Search

Context Neonatal severe hyperparathyroidism (NSHPT) is rare and potentially lethal. It is usually from homozygous or heterozygous germline-inactivating CASR variant(s). NSHPT shows a puzzling range of serum calcium and parathyroid hormone (PTH) levels. Optimal therapy is unclear. Evidence acquisition We categorized genotype/phenotype pairings related to CASRs. For the 2 pairings in NSHPT, each of 57 cases of neonatal severe hyperparathyroidism required calcium, PTH, upper normal PTH, and dosage of a germline pathogenic CASR variant. Evidence synthesis Homozygous and heterozygous NSHPT are 2 among a spectrum of 9 genotype/phenotype pairings relating to CASRs and NSHPT. For the 2 NSHPT pairings, expressions differ in CASR allelic dosage, CASR variant severity, and sufficiency of maternofetal calcium fluxes. Homozygous dosage of CASR variants was generally more aggressive than heterozygous. Among heterozygotes, high-grade CASR variants in vitro were more pathogenic in vivo than low-grade variants. Fetal calcium insufficiency as from maternal hypoparathyroidism caused fetal secondary hyperparathyroidism, which persisted and was reversible in neonates. Among NSHPT pairings, calcium and PTH were higher in CASR homozygotes than in heterozygotes. Extreme hypercalcemia (above 4.5 mM; normal 2.2–2.6 mM) is a robust biomarker, occurring only in homozygotes (83% of that pairing). It could occur during the first week. Conclusions In NSHPT pairings, the homozygotes for pathogenic CASR variants show higher calcium and PTH levels than heterozygotes. Calcium levels above 4.5 mM among NSHPT are frequent and unique only to most homozygotes. This cutoff supports early and robust diagnosis of CASR dosage. Thereby, it promotes definitive total parathyroidectomy in most homozygotes.

PURPOSE: Parathyroid cancer is a rare tumor associated with poor prognosis particularly when disseminated. While chemotherapy and/or radiotherapy are of no clinical value in disseminated disease, immunotherapy should be considered. SUBJECT AND RESULTS: A patient with CDC73-associated metastatic parathyroid carcinoma was treated with combined anti-hPTH immunotherapy and surgery. CONCLUSIONS: Following five courses of anti-hPTH immunotherapy and subsequent surgery, a 12-year long remission of disseminated parathyroid cancer is reported. This case further supports the ever-expanding spectrum of cancers that may benefit from immunotherapy.

Context: Neonatal severe hyperparathyroidism (NSHPT) is a rare and life-threatening emergency. It includes generalized hyperparathyroid bone disease and respiratory distress from combinations among a narrowed thorax, rib fractures, hypotonia, and biochemical disturbances. Successful therapy is compatible with long life and a healthy prognosis. However, neuromotor retardation may persist after otherwise successful therapy. The time and amplitude of hypercalcemia likely correlate with irreversible neuromotor retardation; thus, early intervention seems critical in many cases. NSHPT is usually caused by homozygous or heterozygous pathogenic variant(s) of the CASR; a heterozygous variant of this gene is also the usual cause of familial hypocalciuric hypercalcemia (FHH or FHH1). Homozygotes and heterozygotes with NSHPT are often not distinguished in the current literature. In theory, their management should differ. Optimum treatment in homozygotes is early total parathyroidectomy with induction of postoperative hypoparathyroidism. Optimal management of heterozygotes is more complex. It consists in temporizing measures and varies from careful observation without surgery, to bisphosphonates and/or calcimimetics, and to subtotal parathyroidectomy. The heterozygotes can then develop into healthy babies with asymptomatic FHH1. Evidence Acquisition: Each case met strict criteria for “severe” and neonatal disease. We analyzed the core biochemical parameters of the maximal serum calcium and maximal PTH. To compare different immunoassays, PTH was analyzed as a ratio (thus without units) of the raw data divided by the upper limit of its normal range. Each case also required information about the allelic dosage of the pathogenic or likely pathogenic CASR variant(s). Evidence Synthesis: There were 36 cases with homozygous pathogenic CASR variants and 21 cases with heterozygous pathogenic or likely pathogenic variants. Maximal serum calcium was far higher in homozygotes 5.8 +/- 1.5 versus 3.2 +/- 0.2 (P Conclusions: Extreme hypercalcemia greater than 4.5 mM was newly identified as a conservative cutoff that was 100% predictive of homozygosity for pathogenic CASR variants. Extreme hypercalcemia in NSHPT is an early, facile, rapid, and inexpensive determinant of homozygosity for pathogenic variants of the CASR. It should be sought and used to promote early and definitive total parathyroidectomy, whenever it is identified in NSHPT.

Background Loss-of-function germline MEN1 gene mutations account for 75–95% of patients with multiple endocrine neoplasia type 1 (MEN1). It has been postulated that mutations in non-coding regions of MEN1 might occur in some of the remaining patients; however, this hypothesis has not yet been fully investigated. Objective To sequence for the entire MEN1 including promoter, exons and introns in a large MEN1 cohort and determine the mutation profile. Methods and patients A target next-generation sequencing (tNGS) assay comprising 7.2 kb of the full MEN1 was developed to investigate germline mutations in 76 unrelated MEN1 probands (49 familial, 27 sporadic). tNGS results were validated by Sanger sequencing (SS), and multiplex ligation-dependent probe amplification (MLPA) assay was applied when no mutations were identifiable by both tNGS and SS. Results Germline MEN1 variants were verified in coding region and splicing sites of 57/76 patients (74%) by both tNGS and SS (100% reproducibility). Thirty-eight different pathogenic or likely pathogenic variants were identified, including 13 new and six recurrent variants. Three large deletions were detected by MLPA only. No mutation was detected in 16 patients. In untranslated, regulatory or in deep intronic MEN1 regions of the 76 MEN1 cases, no point or short indel pathogenic variants were found in untranslated, although 33 benign/likely benign and three new VUS variants were detected. Conclusions Our study documents that point or short indel mutations in non-coding regions of MEN1 are very rare events. Also, tNGS proved to be a highly effective technology for routine genetic MEN1 testing.

Background Approximately 10% of patients with primary hyperparathyroidism (PHPT) have hereditary disease. Hereditary PHPT may be syndromic (MEN1, 2, and 4 and hyperparathyroidism-jaw tumor syndrome) or non-syndromic (familial isolated PHPT). There are limited data on the probability of testing positive for genetic mutation based on clinical presentation. The aim of this study was to determine potential associations between clinical and biochemical features and mutation in susceptibility genes for PHPT in patients with a family history of PHPT. Study Design A retrospective analysis of 657 patients who had an initial parathyroidectomy for PHPT at a tertiary referral center. Logistic regression analyses were performed in 205 patients with a family history of PHPT to identify factors associated with a positive genetic test. Results Of 657 patients, 205 (31.2%) had a family history of PHPT. Of those 205 patients, 123 (60%) had a germline mutation detected (91 MEN1 , 14 CDC73 , and 18 GCM2 ). In univariate analysis, younger age (45 years and younger), male sex, multigland disease, and parathyroid carcinoma were associated with positive germline mutation; biochemical cure after an initial parathyroidectomy was less frequent in patients with familial PHPT (96.2% vs 89.2%; p = 0.005). In multivariable analysis, age 45 years and younger, male sex, and multigland disease were independent factors associated with positive genetic testing. Conclusions In addition to a family history of PHPT, male sex, age 45 years and younger, and presence of multigland disease, should prompt physicians to offer the opportunity for genetic counseling and testing, as it could influence the management of patients with PHPT.

Introduction Multiple endocrine neoplasia type 1 (MEN1) is complex with regard to clinical expressions, management, and molecular pathways. Advances are being made broadly and in focused aspects. Selected topics are presented for their developments since publication of the most recent MEN1 consensus guidelines 6 years ago. Methods Topics were selected for clinical impact or broad interest or both. For each topic, information was obtained from original reports and reviews. Results The selected topics are as follows: tumor behavior and breast cancer in MEN1; foregut neuroectoderm tumor screening, biomarkers periodically to detect tumor emergence of foregut neuroectoderm tumors, 68Ga dotatate positron emission tomography/computed tomography for pancreatic and duodenal neuroectodermal tumor imaging, and glucagon-like peptide-1 receptor scintigraphy for insulinoma; therapy, the size of pancreatic neuroendocrine tumor (NET) as one criterion for surgery, minimally invasive surgery of pancreatic NETs, and 177Lu dotatate therapy; MEN1 gene, the search for the MEN1/menin pathway and MEN1 or GCM2 mutation in familial isolated hyperparathyroidism, and MEN1 mutation-positive vs mutation-negative cases of MEN1 are different. Conclusions MEN1 topics are a rich and fast-moving area. Important highlights stand out, and major and rapid advances will continue into the near future.

Familial hypocalciuric hypercalcemia (FHH) causes lifelong hypercalcemia with features that overlap with typical primary hyperparathyroidism (PHPT). The incompleteness of this overlap has led to divergent nomenclatures for FHH. I compare two nomenclatures. One sets FHH as an entity distinct from PHPT. The other groups FHH with PHPT but conditions FHH as atypical PHPT. I analyzed selected articles about calcium-sensing receptors, FHH, PHPT, CASR, GNA11, and AP2S1. FHH usually results from a heterozygous germline inactivating mutation of the CASR, and less frequently from mutation of GNA11 or AP2S1. The CASR encodes the calcium-sensing receptors. These are highly expressed on parathyroid cells, where they sense serum calcium concentration and regulate suppression of PTH secretion by serum calcium. Their mutated expression in the kidney in FHH causes increased renal tubular reabsorption of calcium (hypocalciuria). Many FHH features are shared with PHPT and thus support FHH as a form of PHPT. These include a driver mutation expressed mainly in the parathyroid cells. The mutation causes a parathyroid cell insensitivity to extracellular calcium in vivo and in vitro, a right-shift of the set point for suppression of PTH secretion by calcium. Serum PTH is normal or mildly elevated; ie, it is not appropriately suppressed by hypercalcemia. Total parathyroidectomy causes hypoparathyroidism and durable remission of hypercalcemia. Some other features are not shared with PHPT and could support FHH as a distinct entity. These include onset of hypercalcemia in the first week of life, frequent persistence of hypercalcemia after subtotal parathyroidectomy, and hypocalciuria. The features supporting FHH as a form of PHPT are stronger than those favoring FHH as a distinct entity. Classifying FHH as an atypical form of PHPT represents compact nomenclature and supports current concepts of pathophysiology of FHH and PHPT. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Context: Familial hypocalciuric hypercalcemia (FHH) causes lifelong hypercalcemia that even persists after subtotal parathyroidectomy. Symptoms are usually mild. Past recommendations have often been for monitoring and against surgical or pharmacologic treatments. Methods: Review of publications about FHH, calcium-sensing receptors (CaSRs), and calcimimetics. Results: FHH reflects heterozygous germline mutation of CASR, GNA11, or AP2S1. These mutations inactivate the CaSRs in the parathyroid cell. Thereby, they shift the serum calcium set point to higher values and cause hypercalcemia. Calcimimetic drugs enhance the effects of calcium on the CaSRs and thereby inhibit the parathyroid cell. Calcimimetic drugs are indicated in adults with primary hyperparathyroidism without a good surgical option. Calcimimetic safety and efficacy are not established in children younger than age 18 years. Recent case reports have described treatment of FHH with calcimimetics. Success was classified as combinations of subjective improvements and decreases of serum calcium levels, but not necessarily into the normal range. Treatment was successful in 14 of 16 cases (88%). Conclusion: Deductions based on these case reports have limitations. For example, failures of therapy may not have been reported. Cost of the drug might be rate limiting. Calcimimetics can be offered to adults with FHH and those in whom the serum calcium level is >0.25 mM (1 mg/dL) beyond the upper limit of normal or with possible symptoms of hypercalcemia. Calcimimetics can now be offered to more adults with FHH., Treatment with a calcimimetic was successful in 14 of 16 reported cases of FHH. Calcimimetics can be used in more cases of FHH.

ObjectiveTo determine the association between neuroendocrine tumor (NET) biomarker levels and the extent of disease as assessed by68Ga DOTATATE PET/CT imaging.DesignA retrospective analysis of a prospective database of patients with NETs.MethodsFasting plasma chromogranin A (CgA), neuron-specific enolase (NSE), gastrin, glucagon, vasoactive intestinal peptide (VIP) and pancreatic polypeptide (PP), and 24-h urinary 5-hydroxyindoleacetic acid (5-HIAA) levels were measured. Correlation between biomarkers and total68Ga-DOTATATE-avid tumor volume (TV) was analyzed.ResultsThe analysis included 232 patients. In patients with pancreatic NETs (n = 112),68Ga-DOTATATE TV correlated with CgA (r = 0.6,P = 0.001, Spearman). In patients with multiple endocrine neoplasia type 1 (n = 39),68Ga-DOTATATE TV correlated with glucagon (r = 0.5,P = 0.01) and PP levels (r = 0.5,P = 0.049). In patients with von Hippel–Lindau (n = 24), plasma VIP (r = 0.5,P = 0.02) and PP levels (r = 0.7,P 68Ga-DOTATATE TV. In patients with small intestine NET (SINET,n = 74),68Ga-DOTATATE TV correlated with CgA (r = 0.5,P = 0.02) and 5-HIAA levels (r = 0.7,P P = 0.001).68Ga-DOTATATE TV in patients with NET of unknown primary (n = 16) and those with NET of other primary location (n = 30) correlated with 5-HIAA levels (r = 0.8,P = 0.002 andr = 0.7,P = 0.02 respectively).ConclusionsOur data supports the use of specific NET biomarkers based on the site of the primary NET and the presence of hereditary syndrome-associated NET. High urinary 5-HIAA levels indicate the presence of metastatic disease in patients with SINET.

Context: Germline gain-of-function variants in the transcription factor GCM2 were found in 18% of kindreds with familial isolated hyperparathyroidism (FIHP). These variants [c.1136T>A (p.Leu379Gln) and c.1181A>C (p.Tyr394Ser)] were located in a 17-amino acid transcriptional inhibitory domain named C-terminal conserved inhibitory domain (CCID). Objective: We investigated the ethnicity of individuals with germline variants in the GCM2 CCID in our primary hyperparathyroidism (PHPT) patient samples and in the Genome Aggregation Database. Design: Ethnicity information was obtained from an in-house clinical database and genetic counseling. Sanger sequencing of blood DNA was used to determine the genotype of the GCM2 CCID region. Luciferase reporter assays were performed to determine the functional impact of GCM2 variants. Setting and Patients: National Institute of Diabetes and Digestive and Kidney Diseases endocrine clinic is a service that accepts PHPT referral patients. Results: The GCM2 p.Tyr394Ser variant was found in 41% [95% confidence interval (CI), 22% to 64%] of Ashkenazi Jewish (AJ) kindreds with FIHP and in 27% (95% CI, 17% to 40%) of AJ patients with sporadic PHPT. The p.Tyr394Ser variant was also found in sporadic PHPT patients of European ancestry, but at a lower prevalence. The p.Leu379Gln variant was found in 8% (95% CI, 1% to 26%) of European kindreds with FIHP and 0.5% (95% CI, 0% to 3.0%) of sporadic PHPT cases of European ancestry. The sporadic PHPT patients with GCM2-activating variants often had multigland involvement or postoperative recurrent or persistent disease. Conclusions: Specific GCM2-activating variants enriched among various ethnic backgrounds could contribute to a large number of cases with FIHP or sporadic PHPT., Specific GCM2 activating variants enriched in various ethnic backgrounds could contribute to a large number of cases with familial isolated hyperparathyroidism or sporadic primary hyperparathyroidism.

ContextFamilial isolated hyperparathyroidism (FIHP) is defined as familial primary hyperparathyroidism (FH) without a characteristic extraparathyroidal feature of a more complex hyperparathyroid syndrome. New concepts of FIHP have been developed within this definition. FIHP has been difficult to study due to small kindreds and mildly symptomatic cases.Evidence AcquisitionSearches were through PubMed for FIHP, other FH syndromes, and the gene(s) mutated in each.Evidence SynthesisWithin its definition, the current concept of FIHP has clinical and mutational components that can include incomplete expressions of multiple endocrine neoplasia type 1 (MEN1) familial hypocalciuric hypercalcemia, hyperparathyroidism-jaw tumor syndromes, or their mutations. Newest concepts of FIHP focus on kindreds without mutation of the MEN1, CASR, or CDC73 genes; 17% have germline activating mutation of the gene for the GCM2 transcription factor. The FIHP kindreds with or without GCM2 mutation contain a median of only two cases of primary hyperparathyroidism. The small kindred size in both subgroups of FIHP is probably caused by a low rate of screening among relatives. Persons with FIHP and GCM2 mutation present as adults with mild hypercalcemia and multiple parathyroid tumors.ConclusionThe current concept of FIHP led to a focus on small kindreds without mutation of MEN1, CASR, or CDC73. These assisted in identifying germline activating GCM2 mutations in 17% of kindreds. Clinical and mutational characterization in more cases is needed to determine if there are any unique clinical features of FIHP, with or without mutation of GCM2.

Six syndromes of familial hyperparathyroidism are compared: 1) Familial hypocalciuric hypercalcemia (FHH) expresses primary hyperparathyroidism (PHPT) beginning at birth with lifelong hypercalcemia. There is nonsuppressed PTH secretion from outwardly normal parathyroid glands. It reflects germline heterozygous mutation in CASR, GNA11, or AP2S1. 2) Neonatal severe primary hyperparathyroidism is severest of the six syndromes. It requires urgent total parathyroidectomy in infancy. It usually reflects biallelic inactivation of the CASR. 3) Multiple endocrine neoplasia type 1 (MEN1) is most frequently expressed as PHPT with asymmetric enlargement of 3–4 parathyroids. Benign or malignant tumors may occur among 30 other tissues. It is predisposed by germline inactivation of MEN1 or rarely by inactivation of a cyclin dependent kinase inhibitor, and then termed MEN4. 4) Multiple endocrine neoplasia type 2A from RET activating mutation rarely presents as familial hyperparathyroidism, because medullary thyroid cancer and pheochromocytoma are more prominent. 5) Hyperparathyroidism-jaw tumor syndrome (HPT-JT) has frequent PHPT and benign jaw tumors. Twenty percent develop parathyroid cancer. It is predisposed by inactivating mutation in CDC73. 6) Familial isolated hyperparathyroidism causes multiple parathyroid tumors. It can be an incomplete expression of FHH, MEN1, HPT-JT or even of relatives without a shared driver mutation. However, in 20% of families it reflects GCM2 activating mutation. Five of the PHPT syndromes reflect overgrowth of parathyroid tissue; in contrast, familial hypocalciuric hypercalcemia reflects dysregulation of PTH secretion with little or no parathyroid overgrowth. These differences underlie major differences in clinical expression.

Hereditary primary hyperparathyroidism may be syndromic or nonsyndromic (familial isolated hyperparathyroidism). Recently, germline activating mutations in the GCM2 gene were identified in a subset of familial isolated hyperparathyroidism. This study examined the clinical and biochemical characteristics and the treatment outcomes of GCM2 mutation-positive familial isolated hyperparathyroidism as compared to sporadic primary hyperparathyroidism.We performed a retrospective analysis of clinical features, parathyroid pathology, and operative outcomes in 18 patients with GCM2 germline mutations and 457 patients with sporadic primary hyperparathyroidism.Age at diagnosis, sex distribution, race/ethnicity, and preoperative serum calcium concentrations were similar between the 2 groups. The preoperative serum levels of intact parathyroid hormone was greater in patients with GCM2-associated primary hyperparathyroidism (239 ± 394 vs 136 ± 113, P = .005) as were rates of multigland disease and parathyroid carcinoma in the GCM2 group (78% vs 14.3%, P .001 and 5% vs 0%, P = .04, respectively), but the biochemical cure rate was less in the GCM2 group (86% vs 99%, P .001).GCM2-associated primary hyperparathyroidism patients have greater preoperative parathyroid hormone levels, a greater rate of multigland disease, a lesser rate of biochemical cure, and a substantial risk of parathyroid carcinoma. Knowledge of these clinical characteristics could optimize the surgical management of GCM2-associated familial isolated hyperparathyroidism.

Summary Objective In patients with multiple endocrine neoplasia type 1 (MEN1), Cushing’s syndrome (CS) from endogenous hypercortisolism can result from pituitary, adrenal or other endocrine tumours. The purpose of this study was to characterize the range of presentations of CS in a large series of MEN1 patients. Design Retrospective review of NIH Clinical Center inpatient records over an approximately 40-year period. Patients Nineteen patients (eight males, 11 females) with CS and MEN1. Measurements Biochemical, imaging, surgical and pathological findings. Results An aetiology was determined for 14 of the 19 patients with CS and MEN1: 11 (79%) had Cushing’s disease (CD) and three (21%) had ACTH-independent CS owing to adrenal tumours, frequencies indistinguishable from sporadic CS. Three of 11 MEN1 patients with CD (27%) had additional non-ACTH-secreting pituitary microadenomas identified at surgery, an incidence 10-fold higher than in sporadic CD. Ninety-one per cent of MEN1 patients with CD were cured after surgery. Two of three MEN1 patients with ACTH-independent CS (67%) had adrenocortical carcinoma. One patient with adrenal cancer and another with adrenal adenoma were cured by unilateral adrenalectomy. No case of ectopic ACTH secretion was identified in our patient cohort. The aetiology of CS could not be defined in five patients; in three of these, hypercortisolism appeared to resolve spontaneously. Conclusions The tumour multiplicity of MEN1 can be reflected in the anterior pituitary, MEN1-associated ACTH-independent CS may be associated with aggressive adrenocortical disease and an aetiology for CS in MEN1 may be elusive in a substantial minority of patients.

Background: At the Third International Workshop on Asymptomatic Primary Hyperparathyroidism (PHPT) in May 2008, recent data on the disease were reviewed. We present the results of a literature review on issues arising from the clinical presentation and natural history of PHPT. Methods: Questions were developed by the International Task Force on PHPT. A comprehensive literature search for relevant studies was reviewed, and the questions of the International Task Force were addressed by the Consensus Panel. Conclusions: 1) Data on the extent and nature of cardiovascular involvement in those with mild disease are too limited to provide a complete picture. 2) Patients with mild PHPT have neuropsychological complaints. Although some symptoms may improve with surgery, available data remain inconsistent on their precise nature and reversibility. 3) Surgery leads to long-term gains in spine, hip, and radius bone mineral density (BMD). Because some patients have early disease progression and others lose BMD after 8–10 yr, regular monitoring (serum calcium and three-site BMD) is essential in those followed without surgery. Patients may present with normocalcemic PHPT (normal serum calcium with elevated PTH concentrations; no secondary cause for hyperparathyroidism). Data on the incidence and natural history of this phenotype are limited. 4) In the absence of kidney stones, data do not support the use of marked hypercalciuria (>10 mmol/d or 400 mg/d) as an indication for surgery for patients. 5) Patients with bone density T-score −2.5 or less at the lumbar spine, hip, or distal one third radius should have surgery.

Five syndromes share predominantly hyperplastic glands with a primary excess of hormones: neonatal severe primary hyperparathyroidism, from homozygous mutatedCASR, begins severelyin utero; congenital non-autoimmune thyrotoxicosis, from mutatedTSHR, varies from severe with fetal onset to mild with adult onset; familial male-limited precocious puberty, from mutatedLHR, expresses testosterone oversecretion in young boys; hereditary ovarian hyperstimulation syndrome, from mutatedFSHR, expresses symptomatic systemic vascular permeabilities during pregnancy; and familial hyperaldosteronism type IIIA, from mutatedKCNJ5, presents in young children with hypertension and hypokalemia. The grouping of these five syndromes highlights predominant hyperplasia as a stable tissue endpoint and as their tissue stage for all of the hormone excess. Comparisons were made among this and two other groups of syndromes, forming a continuum of gland staging: predominant oversecretions express little or no hyperplasia; predominant hyperplasias express little or no neoplasia; and predominant neoplasias express nodules, adenomas, or cancers. Hyperplasias may progress (5 of 5) to neoplastic stages while predominant oversecretions rarely do (1 of 6; frequencies differPPP

The past six decades have witnessed the initial clinical descriptions of neonatal severe hyperparathyroidism (NSHPT) and familial hypocalciuric hypercalcemia (FHH), biochemical and physiologic studies suggesting abnormal calcium sensing by parathyroid glands and kidneys, and finally the description of three distinct molecular causes of FHH. FHH1 results from heterozygous inactivating mutations in the extracellular calcium-sensing receptor (CaSR), usually manifesting as mild to moderate resistance of parathyroid and kidney to calcium, mild PTH-dependent hypercalcemia, and relative hypocalciuria. NSHPT is caused by more severe calcium resistance owing to heterozygous, compound heterozygous, or homozygous CaSR mutations. Recent studies have identified the molecular bases for two additional forms of FHH linked to chromosome 19, FHH2 and FHH3, caused by mutations in downstream proteins in the CaSR signaling pathway. Further studies will likely further expand the range of clinical presentations of FHH, enhance our diagnosis of these conditions, and improve therapies for treating NSHPT and the occasional FHH patients requiring medical or surgical therapy.

Each multiple endocrine neoplasia (MEN) syndrome expresses striking features of hormone oversecretion from its own characteristic group of tissues. Additional expressions include non-hormonal tumours in each MEN syndrome and selected cancers in some syndromes. The complexity of its stereotyped features results in difficult management issues that often justify cooperation across multiple specialties. MEN syndromes, though rare, have long received intense study as models for more common diseases. The syndromal nature often with a large pedigree has promoted recent discovery of the main gene that differs for each of the six MEN syndromes. Each mutant gene has been introduced into clinical decision-making and into further clarification of tumorigenesis. This mini-symposium is related to the 9th International Workshop on Multiple Endocrine Neoplasia in June 2004; it consists of six manuscripts. They report new developments in clinical practices and in basic understandings about this rapidly advancing field.

No variant of multiple endocrine neoplasia type 1 (MEN1) has been reproducible among families. We examined two large kindreds with MEN1 variants, and we compared these to past reports. The two kindreds were followed up for 20-30 yr with MEN1 tumors in 30 members. Results in cases from two kindreds were that 93% showed parathyroid adenoma, 40% pituitary tumor (always prolactinoma), and 27% enteropancreatic endocrine tumor. The latter included 10% insulinoma, 7% nonfunctioning islet tumor, but only 10% gastrinoma. Compared with prior large series, this lower prevalence of gastrinoma (10% vs. 42%, P < 0.01) and higher prevalence of prolactinoma (40% vs. 22%, P < 0.01) define this variant. Many possible biases of retrospective analyses were excluded as possible explanations. Previously sequenced DNA showed no characteristic MEN1 mutation in these two kindreds and in a third, reported previously; the lack of any shared MEN1 mutation also excluded common ancestry for MEN1 among the three kindreds. The causes for differences between this variant and typical MEN1 are unknown. In conclusion, this variant shows more frequent prolactinoma and less frequent gastrinoma than typical MEN1; the variant is reproducible among kindreds. MEN1 carriers in such families should have periodic monitoring adjusted for the expected penetrance of tumors.

To date, data on pituitary adenomas in MEN type 1 (MEN1) still have to be evaluated. We analyzed the data of a large series of 324 MEN1 patients from a French and Belgian multicenter study. Data on pituitary disease were compared with those from 110 non-MEN1 patients with pituitary adenomas, matched for age, year of diagnosis, and follow-up period. Genetic analysis of the MEN1 gene was performed in 197 of the MEN1 patients. In our MEN1 series, pituitary disease occurred in 136 of 324 (42%), less frequently than hyperparathyroidism (95%, P < 0.001) and endocrine enteropancreatic tumors (54%, P < 0.01). Mean age of onset of pituitary tumors was 38.0 ± 15.3 yr (range, 12-83 yr). Pituitary disease was associated with hyperparathyroidism in 90% of cases, with enteropancreatic tumors in 47%, with adrenal tumors in 16%, and with thoracic neuroendocrine tumors in 4%. Pituitary disease was the initial lesion of MEN1 in 17% of all MEN1 patients. MEN1 pituitary adenomas were significantly more frequent in women than in men (50% vs. 31%, P < 0.001). Among the 136 pituitary adenomas, there were 85 prolactinomas and 12 GH-secreting, 6 ACTH-secreting, 13 cosecreting, and 20 nonsecreting tumors. Eighty-five percent of MEN1-related pituitary lesions were macroadenomas (vs. 42% in non-MEN1 patients, P < 0.001), including 32% of invasive cases. Among secreting adenomas, hormonal hypersecretion was normalized, after treatment, in only 42% (vs. 90% in non-MEN1 patients, P < 0.001), with a median follow-up of 11.4 yr. No correlation was found between the type of MENI germ-line mutation and the presence or absence of pituitary adenoma. Our study, based on a large group of MEN1 patients, shows that pituitary adenomas occur in 42% of the cases and are characterized by a larger size and a more aggressive presentation than without MEN1.

Primary hyperparathyroidism (PHPT) is a common endocrine disease caused by parathyroid tumors (adenoma or hyperplasia). The hypersecreting parathyroid tumor elevates serum parathyroid hormone level, which causes hypercalcemia and the classical symptoms of PHPT, including kidney stones, osteoporosis, and neuromuscular symptoms associated with hypercalcemia, such as muscle weakness, drowsiness, and depression. Familial PHPT occurs in an isolated nonsyndromal form, termed familial isolated hyperparathyroidism (FIHP), or as part of a syndrome, such as multiple endocrine neoplasia type 1 or hyperparathyroidism-jaw tumor syndrome. We performed exome sequencing on germline DNA of eight index cases from eight unrelated kindreds with FIHP. Rare variants were identified (minor allele frequency Citation Format: Bin Guan, James M. Welch, Julie C. Sapp, Hua Ling, Meghana Vemulapalli, Yulong Li, Jennifer J. Johnston, Electron Kebebew, Leslie G. Biesecker, William F. Simonds, Stephen J. Marx, Sunita K. Agarwal. Germline activating mutations in the proto-oncogene GCM2 in primary hyperparathyroidism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5646. doi:10.1158/1538-7445.AM2017-5646

Context:Most syndromes with benign primary excess of a hormone show positive coupling of hormone secretion to size or proliferation in the affected hormone secretory tissue. Syndromes that lack this coupling seem rare and have not been examined for unifying features among each other.Evidence Acquisition:Selected clinical and basic features were analyzed from original reports and reviews. We examined indices of excess secretion of a hormone and indices of size of secretory tissue within the following three syndromes, each suggestive of uncoupling between these two indices: familial hypocalciuric hypercalcemia, congenital diazoxide-resistant hyperinsulinism, and congenital primary hyperaldosteronism type III (with G151E mutation of the KCNJ5 gene).Evidence Synthesis:Some unifying features among the three syndromes were different from features present among common tumors secreting the same hormone. The unifying and distinguishing features included: 1) expression of hormone excess as early as the first days of life; 2) normal size of tissue that oversecretes a hormone; 3) diffuse histologic expression in the hormonal tissue; 4) resistance to treatment by subtotal ablation of the hormone-secreting tissue; 5) causation by a germline mutation; 6) low potential of the same mutation to cause a tumor by somatic mutation; and 7) expression of the mutated molecule in a pathway between sensing of a serum metabolite and secretion of hormone regulating that metabolite.Conclusion:Some shared clinical and basic features of uncoupling of secretion from size in a hormonal tissue characterize three uncommon states of hormone excess. These features differ importantly from features of common hormonal neoplasm of that tissue.

This is a consensus statement from an international group, mostly of clinical endocrinologists. MEN1 and MEN2 are hereditary cancer syndromes. The commonest tumors secrete PTH or gastrin in MEN1, and calcitonin or catecholamines in MEN2. Management strategies improved after the discoveries of their genes. MEN1 has no clear syndromic variants. Tumor monitoring in MEN1 carriers includes biochemical tests yearly and imaging tests less often. Neck surgery includes subtotal or total parathyroidectomy, parathyroid cryopreservation, and thymectomy. Proton pump inhibitors or somatostatin analogs are the main management for oversecretion of entero-pancreatic hormones, except insulin. The roles for surgery of most entero-pancreatic tumors present several controversies: exclusion of most operations on gastrinomas and indications for surgery on other tumors. Each MEN1 family probably has an inactivating MEN1 germline mutation. Testing for a germline MEN1 mutation gives useful information, but rarely mandates an intervention. The most distinctive MEN2 variants are MEN2A, MEN2B, and familial medullary thyroid cancer (MTC). They vary in aggressiveness of MTC and spectrum of disturbed organs. Mortality in MEN2 is greater from MTC than from pheochromocytoma. Thyroidectomy, during childhood if possible, is the goal in all MEN2 carriers to prevent or cure MTC. Each MEN2 index case probably has an activating germline RET mutation. RET testing has replaced calcitonin testing to diagnose the MEN2 carrier state. The specific RET codon mutation correlates with the MEN2 syndromic variant, the age of onset of MTC, and the aggressiveness of MTC; consequently, that mutation should guide major management decisions, such as whether and when to perform thyroidectomy.

Multiple endocrine neoplasia type 1 (MEN 1) is associated with parathyroid, enteropancreatic, pituitary, and other tumors. The MEN1 gene, a tumor suppressor, is located on chromosome 11. Affected individuals inherit a mutated MEN1 allele, and tumorigenesis in specific tissues follows inactivation of the remaining MEN1 allele. MEN 1-associated endocrine tumors usually become clinically evident in late adolescence or young adulthood, as high levels of PTH, gastrin, or PRL. Because each of these tumors can usually be controlled with medications and/or surgery, MEN 1 has been regarded mainly as a treatable endocrinopathy of adults. Unlike in MEN 2, early testing of children in MEN 1 families is not recommended. We report a 2.3-cm pituitary macroadenoma in a 5-yr-old boy with familial MEN 1. He presented with growth acceleration, acromegaloid features, and hyperprolactinemia. We tested systematically to see whether his pituitary tumor had causes similar to or different from a typical MEN 1 tumor. Germ line DNA of the propositus and his affected relatives revealed a heterozygous point mutation in the MEN1 gene, which leads to a His139Asp (H139D) amino acid substitution. The patient had no other detectable germ-line mutations on either MEN1 allele. DNA sequencing and fluorescent in situ hybridization with a MEN1 genomic DNA sequence probe each demonstrated one copy of the MEN1 gene to be deleted in the pituitary tumor and not in normal DNA, proving MEN1 "second hit" as a tumor cause. Gsalpha mutation, common in nonhereditary GH-producing tumors, was not detected in this tumor. We conclude that this pituitary macroadenoma showed molecular genetic features of a typical MEN 1-associated tumor. This patient represents the earliest presentation of any morbid endocrine tumor in MEN 1. A better understanding of early onset MEN 1 disease is needed to formulate recommendations for early MEN 1 genetic testing.

Multiple endocrine neoplasia type 1 (MEN1) gene mutations are reported in some gastrinomas occurring in patients without MEN1 as well as in some other pancreatic endocrine tumors (PETs). In some inherited syndromes phenotype-genotype correlations exist for disease severity, location, or other manifestations. The purpose of the present study was to correlate mutations of the MEN1 gene in a large cohort of patients with sporadic gastrinomas to disease activity, tumor location, extent, and growth pattern. DNA was extracted from frozen gastrinomas from 51 patients and screened by dideoxyfinger-printing (ddF) for abnormalities in the 9 coding exons and adjacent splice junctions of the MEN1 gene. Tumor DNA exhibiting abnormal ddF patterns was sequenced for mutations. The findings were correlated with clinical manifestations of the disease, primary tumor site, disease extent, and tumor growth postoperatively. Tumor growth was determined by serial imaging studies. Sixteen different MEN1 gene mutations in the 51 sporadic gastrinomas (31%) were identified (11 truncating, 4 missense, and 1 in-frame deletion). Nine of the 16 mutations were located in exon 2 compared to 7 of 16 in the remaining 8 coding exons (P = 0.005 on a per nucleotide basis). Primary pancreatic or lymph node gastrinomas with a mutation had only exon 2 mutations, whereas duodenal tumors uncommonly harbored exon 2 mutations (P = 0.011). Similarly, small primary tumors (

Hereditary endocrine hyperfunction is categorized here as neoplastic or not neoplastic. The disorders and their mutated genes are subdivided further by hyperfunctional hormone secretory tissue (Table 1). For example, the parathyroids hyperfunction in at least three hereditary neoplastic syndromes [multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 2a (MEN2a), and hyperparathyroidism-jaw tumor syndrome (HPT-JT)], each associated with one distinct gene (1, 2) or locus (3–5). Alternately, the parathyroids can be overactive in two hereditary non-neoplastic syndromes–familial hypocalciuric hypercalcemia (FHH) or neonatal severe primary hyperparathyroidism (NSHPT). Either is usually caused by mutations of the CaSR gene (6–9); two other undiscovered genes account for FHH in a few families (10, 11). A similar classification dichotomy applies to hereditary hyperfunction of pancreatic islet b cells (1, 12–17), of thyrocytes (18–23), or of Leydig cells (19, 24–26) (Table 1). For didactic purposes, this analysis omits endocrine tissue without separate hereditary disorders in each of the two categories. For example, hereditary pheochromocytoma may arise from neoplasia with germline mutation of VHL (12), RET (2), or NF1, but apparently not from non-neoplastic processes. This analysis also excludes dysfunctions outside the hyperfunctional endocrine tissue (for example, hereditary hyperandrogenism can be caused by activation of the CRF/ACTH axis secondary to defective cortisol synthesis).

Adrenocortical tumors occur as sporadic tumors, as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome or as part of other hereditary disorders. We recently cloned the MEN1 gene, a tumor-suppressor gene located on chromosome 11q13. Subsequently, we showed that sequential somatic inactivation of both alleles of the MEN1 gene contributes to the development of some sporadic endocrine neoplasms (parathyroid, enteropancreatic neuroendocrine, bronchial carcinoid, and pituitary tumors). We now studied whether somatic inactivation of the MEN1 gene contributes to the pathogenesis of sporadic adrenocortical neoplasms. Seven adrenocortical carcinomas, 2 adrenocortical carcinoma cell lines, and 11 aldosterone-secreting, 8 cortisol-secreting, and 5 nonsecreting benign adrenocortical tumors were studied. Seven tumors (5 of 5 carcinomas, 2 of 21 nonsecreting benign adenomas; P < 0.001) exhibited loss of heterozygosity on 11q13. All 33 tumors and cell lines were screened for mutation throughout the MEN1 open-reading frame and adjacent splice junctions. None exhibited a mutation within the MEN1-coding region. We conclude that somatic MEN1 mutation within the MEN1-coding region does not occur commonly in sporadic adrenocortical tumors, although the majority of adrenocortical carcinomas exhibit 11q13 loss of heterozygosity.

Asymptomatic primary hyperparathyroidism (PHPT) is routinely encountered in clinical practices of endocrinology throughout the world. This report distills an update of current information about diagnostics, clinical features, and management of this disease into a set of revised guidelines.Participants, representing an international constituency, with interest and expertise in various facets of asymptomatic PHPT constituted four Workshop Panels that developed key questions to be addressed. They then convened in an open 3-day conference September 19-21, 2013, in Florence, Italy, when a series of presentations and discussions addressed these questions. A smaller subcommittee, the Expert Panel, then met in closed session to reach an evidence-based consensus on how to address the questions and data that were aired in the open forum.Preceding the conference, each question was addressed by a relevant, extensive literature search. All presentations and deliberations of the Workshop Panels and the Expert Panel were based upon the latest information gleaned from this literature search.The expert panel considered all the evidence provided by the individual Workshop Panels and then came to consensus.In view of new findings since the last International Workshop on the Management of Asymptomatic PHPT, guidelines for management have been revised. The revised guidelines include: 1) recommendations for more extensive evaluation of the skeletal and renal systems; 2) skeletal and/or renal involvement as determined by further evaluation to become part of the guidelines for surgery; and 3) more specific guidelines for monitoring those who do not meet guidelines for parathyroid surgery. These guidelines should help endocrinologists and surgeons caring for patients with PHPT. A blueprint for future research is proposed to foster additional investigation into issues that remain uncertain or controversial.

Primary hyperparathyroidism is characterized by hypercalcemia and elevated parathyroid hormone levels. It can be caused by overactivity of one (adenoma or carcinoma) or more (hyperplasia or multiple adenoma) parathyroid glands. Parathyroid adenoma and hyperplasia are usually mono- or oligoclonal neoplasms. To establish whether parathyroid cancer has a genetic composition distinct from parathyroid adenoma, we analyzed 10 adenoma and 10 carcinoma cases by comparative genomic hybridization (CGH). Results show clear differences between the constitution of adenoma and carcinoma genomic DNA. The most frequent genomic alterations in adenoma included deletions on chromosomes 11, 17 (5 of 10 cases), and 22 (7 of 10 cases). In parathyroid carcinoma, frequent chromosomal deletions were on chromosome arm 1p (4 of 10 cases) and chromosome 17 (3 of 10 cases), and gains were on chromosome 5 (3 of 10 cases). Our data indicate that different genetic changes could contribute to the development of parathyroid adenoma and carcinoma; genomic losses predominate in adenoma, and gains along with some losses are found in carcinoma. Furthermore, the CGH results implicate several chromosomal regions that may harbor genes that could be potentially involved in the development of parathyroid adenoma and carcinoma. Published by Elsevier Science Inc.

Dideoxyfingerprinting was used to screen for germline and somatic MEN1 mutations. This method, applied to a panel of germline DNA from 15 probands with multiple endocrine neoplasia type 1 (MEN-1), allowed confident discovery of the MEN1 gene. Germline MEN1 mutation has been found in 47 out of 50 probands with familial MEN-1, in 7 out of 8 cases with sporadic MEN-1, and in 1 out of 3 cases with atypical sporadic MEN-1. Germline MEN1 mutation was not found in any of five probands with familial hyperparathyroidism. Somatic MEN1 mutations were found in 7 out of 33 parathyroid tumours not associated with MEN-1. Allowing for repeating mutations, a total of 47 different germline or somatic MEN1 mutations have been identified. Most predict inactivation of the encoded 'menin' protein. supporting expectations that MEN1 is a tumour suppressor gene. The 16 observed missense mutations were distributed across the gene, suggesting that many domains are important to its as yet unknown functions.

Parathyroid carcinoma is one cause of primary hyperparathyroidism, a condition in which there is hypercalcemia and dysregulated hypersecretion of PTH. In normal, and in some neoplastic parathyroid cells, PTH secretion is mediated by the cell surface calcium-sensing receptor. We describe the first therapeutic use of a novel molecule, a calcimimetic, that has agonist action at the calcium-sensing receptor. A 78-yr-old man with parathyroid carcinoma was admitted with hypercalcemia, markedly elevated PTH, and a change in mental status. He was treated for 17 days with conventional therapy, which included saline hydration, furosemide, pamidronate, and calcitonin. This was ineffective, and on hospital day 18, calcimimetic at a dose of 50 mg, orally, every 6 h was added. On hospital day 25, the dose was increased to 100 mg, orally, every 6 h, and on hospital day 30, saline and furosemide were discontinued. He was discharged on hospital day 40. With several dose adjustments, he has been treated with monotherapy calcimimetic for over 600 days and has not required any other interventions for his parathyroid carcinoma. Mean daily precalcimimetic treatment values of serum ionized calcium and PTH were 1.83 mmol/L and 872 pg/mL, respectively. During hospitalization, at the lower dose of calcimimetic, calcium and PTH decreased to 1.67 mmol/L and 538 pg/mL; with the higher dose they further decreased to 1.51 mmol/L and 444 pg/mL. Since discharge, and despite increasing levels of PTH, serum calcium has remained high, but lower than the admission level and acutely responsive to changes in calcimimetic doses. This compound, a calcimimetic, the first of a new class of compounds with activity at the calcium-sensing receptor, has been used to treat a patient with parathyroid carcinoma. During 2 yr of treatment, no adverse clinical effects have been observed, and it appears to have been effective at controlling hypercalcemia.

Loss of heterozygosity (LOH) for polymorphic markers flanking the multiple endocrine neoplasia type 1 (MEN-1) gene in parathyroid and pancreatic islet tumors from subjects with familial MEN-1 (FMEN-1) has been well documented and has led to the hypothesis that the MEN-1 gene functions as a tumor suppressor. To assess the role of the MEN-1 gene in the pathogenesis of tumors less commonly associated with MEN-1, we employed a large number of highly informative polymorphic markers closely linked to the MEN-1 gene to study a series of 13 such tumors from subjects with FMEN-1 for LOH at 11q13. We were able to identify LOH for 1 or more 11q13 markers in 2 of 3 pituitary tumors, 3 lung carcinoids, and 1 of 2 lipomas. In every case studied, the allele lost represented the normal allele inherited from the unaffected parent. No LOH was detected in 3 skin angiofibromas, an esophageal leiomyoma, or a renal angiomyolipoma despite the presence of at least 2 informative markers for each tumor. Our results suggest that, like that for parathyroid and pancreatic islet tumors, the pathogenesis of pituitary tumors, lung carcinoids, and lipomas occurring in subjects with FMEN-1 probably involves loss of the normal tumor suppressor function of the MEN-1 gene. Our inability to detect 11q13 LOH in skin angiofibromas, leiomyoma, and angiomyolipoma from subjects with FMEN-1 is consistent with the possibility that these neoplasms arose independently by a mechanism unrelated to the MEN-1 gene, but a role for the MEN-1 gene in the pathogenesis of these tumors cannot be definitively excluded until the gene itself is identified and evaluated for small intragenic deletions or point mutations in such tumors.

Context: Multiplicity of hormone-secreting tumors occurs in a substantial portion of hormone-excess states. Multiplicity increases the difficulty of management and drives the selection of special strategies. Evidence Acquisition: This is a synthesis from publications about tumor development and expression, and also about types of clinical strategy for hormone-secreting tumors. Evidence Synthesis: Comparisons were made between patient groups with solitary tumors vs those with multiple tumors. Major themes with clinical relevance emerged. Usually, tumor multiplicity develops from a genetic susceptibility in all cells of a tissue. This applies to hormone-secreting tumors that begin as either polyclonal (such as in the parathyroids of familial hypocalciuric hypercalcemia) or monoclonal tumors (such as in the parathyroids of multiple endocrine neoplasia type 1 [MEN1]). High penetrance of a hereditary tumor frequently results in bilaterality and in several other types of multiplicity. Managements are better for the hormone excess than for the associated cancers. Management strategies can be categorized broadly as ablation that is total, subtotal, or zero. Examples are discussed for each category, and 1 example of each category is named here: 1) total ablation of the entire tissue with effort to replace ablated functions (for example, in C-cell neoplasia of multiple endocrine neoplasia type 2); 2) subtotal ablation with increased likelihood of persistent disease or recurrent disease (for example, in the parathyroid tumors of MEN1); or 3) no ablation of tissue with or without the use of pharmacotherapy (for example, with blockers for secretion of stomach acid in gastrinomas of MEN1). Conclusions: Tumor multiplicity usually arises from defects in all cells of the precursor tissue. Even the optimized managements involve compromises. Still, an understanding of pathophysiology and of therapeutic options should guide optimized management.

The ABO blood type system describes the expression of human blood group antigens found on both erythrocytes and normal tissue throughout the body. We recently reported an association between O blood type and the manifestation of pancreatic neuroendocrine tumors in a cohort of patients with Von Hippel-Lindau syndrome.The aim of the study was to determine whether there is an association of ABO blood type with the development of neuroendocrine tumors in patients with multiple endocrine neoplasia, type 1 (MEN-1).A retrospective analysis of 105 patients with MEN-1 was performed. Demographic, clinical, and biochemical data were analyzed by ABO blood type. Fisher's exact test was used to determine association between ABO blood type and manifestation of neuroendocrine tumor.Demographic and clinical characteristics were similar amongst blood type cohorts. We found an association between O blood type and the manifestation of a primary neuroendocrine tumor of the gastrointestinal tract, lung, pancreas, and thymus in patients with MEN-1 (P = 0.01). Sixteen of 17 (94%) metastatic tumors had type-O blood, compared to 32 of 43 (74%) with a benign tumor who had non-O blood type.Our findings suggest an association between O blood type and the manifestation of a primary neuroendocrine tumor in patients with MEN-1. Prospective clinical studies are warranted to see whether patient blood type status may be a useful addition to current screening and surveillance practices.

Due to frequent multiplicity of tumors in multiple endocrine neoplasia type 1, it may be difficult to decide when to stop a parathyroid exploration. A fall of intraoperative serum PTH by a certain percentage during parathyroid surgery is often used as one criterion for ending the operation.We report two patients with primary hyperparathyroidism due to multiple endocrine neoplasia type 1 who had their first parathyroidectomy at the National Institutes of Health. In both cases, two and a half glands were removed, an extensive search was done for an occult parathyroid tumor, and intraoperative PTH decreased markedly to the lower limits of normal, suggesting a successful operation. Despite this, both patients became hypercalcemic within 3 d after the operation and showed persistent primary hyperparathyroidism. Detailed findings suggest the following course: chronic hypercalcemia had caused near total suppression of PTH secretion by an undiscovered parathyroid tumor (sleeping parathyroid tumor). When the hypercalcemia decreased after surgery due to the removal of the dominant parathyroid tumor(s), the abnormal yet previously suppressed tumor rapidly began to oversecrete PTH and thus caused postoperative hypercalcemia.Even a fall of the intraoperative PTH to the lower limits of the normal range cannot guarantee that removal of all parathyroid tumors has been complete in cases with multiple tumors. These findings likely reflect strikingly differing PTH secretory functions among distinct tumors in the same patient, with hypercalcemia at least from a dominant tumor suppressing PTH secretion by one or more other parathyroid tumors.

Objective Some patients with rickets are resistant to vitamin D and its analogues; we therefore assessed whether or not normal mineralization could be achieved in the absence of an intact 1,25(OH)2D3 receptor-effector system, by the use of intravenous high dose calcium infusion, followed by high dose oral calcium. Design We studied two patients with vitamin D dependent rickets type II and with absent responses to either high dose calcitriol or to oral calcium alone. Daily infusions equivalent to up to 1.4 g elemental calcium supplemented with oral phosphate were given for a period of 3.5 months for the elder sister and 2 months in the younger brother. Both patients were then treated by weekly calcium infusions for 5 months, followed by maintenance on oral calcium equivalent to up to 6 g elemental calcium per day. Patients Two siblings of consanguineous parents, a girl aged 28 months and a boy aged 10 months with vitamin D dependent rickets type II. Measurements Measurements of serum and urine calcium, phosphate and serum alkaline phosphatase were obtained before, during and after the calcium infusions. Twenty-four-hour urinary minerals, electrolytes, creatinine clearance, serum PTH and vitamin D metabolites were measured prior to calcium infusion, then repeated at 2-monthly intervals. Glomerular filtration rate, kidney ultrasound and CT scan were done at 6-monthly intervals. A scalp biopsy was done at the end of i.v. calcium treatment. Results The daily infusions of calcium supplemented with oral phosphate resulted in biochemical responses with normalization of calcium and phosphate in 3-5 days, and of alkaline phosphatase and PTH in 1.5-2 months. Radiological evidence of healing was seen in 42 days. A total of 3.5 months of daily calcium infusion in the elder sister and 2 months in the younger brother resulted in complete healing biochemically and radiologically, with improvement in height. The patients are under current follow-up, with no evidence of nephrocalcinosis or deterioration of glomerular filtration rate. Conclusions (a) The use of intravenous high dose calcium infusions followed by high dose oral calcium is an effective method of treatment of vitamin D dependent rickets type II. (b) The treatment was more effective since it was started early in the course of the disease and led to early healing and better growth with prevention of bone deformities. (c) Early treatment may also lead to improvement in alopecia, the mechanism for which needs to be elucidated. Abbreviations 1,25(OH)2D3, 1,25-dihydroxyvitamin D3 (calcitriol); 24-OHase, 25-(OH)D(3),24-hydroxylase; 1 alpha-(OH)D3, 1 alpha-hydroxyvitamin D3; 25(OH)D3, 25-hydroxyvitamin D3; 1 alpha-OHase, 1 alpha-hydroxylase; PTH, parathyroid hormone.

Familial acromegaly may occur as an isolated pituitary disorder or as a feature of hereditary syndromes, such as multiple endocrine neoplasia type 1 (MEN1) or the Carney complex. Herein, we characterized a newly identified kindred with isolated acromegaly and searched for germline mutation in genes that have been associated with endocrine tumors[ i.e. MEN1, Gsα (GNAS1), and Gi2α (GNAI2)], as well as the GHRH receptor (GHRH-R) gene. Genomic DNA was used to amplify exons 2–10 of MEN1, followed by dideoxy fingerprinting mutation analysis and direct sequencing. The GHRH-R gene was analyzed via direct sequencing of PCR-amplified fragments representing the coding exons and intron-exon junctions. To exclude mutation at hot spot areas of GNAS1 and GNAI2, exons 8 and 9 of GNAS1 and exons 5 and 6 of GNAI2 were amplified and screened for mutation via denaturing gradient gel electrophoresis. No mutations were detected in any of the four genes. The present data extend prior reports of the absence of mutation in MEN1, ...

Well-differentiated neuroendocrine tumors (NETs) of the stomach and pancreas represent 2 major subtypes of gastrointestinal NETs. Historically, there has been little consensus on the classification and management of patients with these tumor subtypes. We provide an overview of well-differentiated NETs of the stomach and pancreas and describe consensus guidelines for the treatment of patients with these malignancies.

Context: Germline mutation in the MEN1 gene is the usual cause of multiple endocrine neoplasia type 1 (MEN1). However, the prevalence of identifiable germline MEN1 mutations in familial MEN1 cases is only 70%. Some cases may have a germline mutation in another gene such as the p27 cyclin-dependent kinase inhibitor (CDKI). Objective: The aim of the study was to investigate cases of MEN1 or related states for germline mutations in all CDKI genes. Methods: A total of 196 consecutive index cases were selected with clear or suspected MEN1 and no identifiable germline MEN1 mutation. Every case was analyzed for germline mutation in each of the seven CDKI genes. Results: We identified benign polymorphisms of the CDKI genes and also 15 other initially unclassified sequence variants. After detailed gene/protein analysis, seven of these 15 variants were classified as probably pathological mutations. Three of these seven were probable mutations of p27. The remaining four were probable pathological mutations in three of the other CDKI genes, thereby implicating these three genes in the germline of human tumors. The identification rates for probably pathological mutations among the 196 index cases were similarly low for each of four CDKI genes: p15 (1%), p18 (0.5%), p21 (0.5%), and p27 (1.5%). No characteristic clinical subtype related to MEN1 was identified among the seven index cases and their families. Conclusion: Rare germline mutation in any among four (p15, p18, p21, and p27) of the seven CDKIs is a probable cause of MEN1 or of some related states.

The mechanisms of early calcitriol (1 alpha,25-dihydroxycholecalciferol) effects, including its receptor activation process as well as its "nongenomic" effects, are poorly understood. Calcitriol causes a rapid accumulation of cGMP, dependent on the presence of normal vitamin D receptors (VDRs). We recently developed an immunocytology method based on rapid microwave fixation suitable to detect the locations of agonist-induced intracellular cGMP accumulation. With the same technique we found that calcitriol induces stepwise and rapid reorganization of VDRs. Here we used this technique to study the subcellular compartmentalization of cGMP accumulation after exposure of cells to various steroid-related agonists and to study the spatial relationship between cGMP accumulation and VDRs. Calcitriol (10 nM) within 15 sec caused clumping of VDRs and accumulation of cGMP around VDR clumps; thereafter (up to 5 min), the cGMP accumulation surrounded VDRs throughout their stepwise reorganization. In fibroblasts from subjects with mutations affecting VDR function, we found disruptions of the calcitriol-induced patterns of cGMP accumulation analogous to the disruptions of VDR reorganization. The colocalization of cGMP accumulation with reorganizing VDRs at early moments after calcitriol addition indicates transduction of the cGMP increase by VDRs inside the cell, rather than by components in the plasma membrane. Other steroid-related agonists caused compartmentalized and sequential changes in cGMP accumulation that seemed specific for each class of agonist. Our findings suggest that compartmentalized cGMP accumulation is an early and common step during activation of steroid-related receptors.

Between 1982 and 1989, 145 patients underwent operations for persistent or recurrent primary hyperparathyroidism (HPT). At re-exploration, 15 patients (10.3%) were found to have locally recurrent parathyroid tumors (11 patients with adenoma and 4 with carcinoma). These 15 patients had 28 previous operations at outside institutions for HPT. Patients with locally recurrent HPT secondary to adenoma had a longer disease-free interval than patients with locally recurrent carcinoma. At the time of evaluation at the National Institutes of Health (NIH) for recurrent or persistent HPT, each patient was symptomatic and patients with carcinoma had significantly more symptoms and higher serum levels of calcium and parathyroid hormone than patients with adenoma. Locally recurrent parathyroid neoplasm was correctly localized by preoperative testing in 14 of 15 patients. These 15 patients underwent 18 reoperations at NIH for excision of locally recurrent parathyroid tumors. Following the final reoperation (two patients had more than one procedure), each patient had normal serum levels of calcium. In addition each patient remains biochemically cured (based on normal serum calcium level), with a median follow-up interval of 21 months. Local recurrence of parathyroid adenoma comprises a small but significant proportion of cases of recurrent or persistent HPT and can be indistinguishable from parathyroid carcinoma. Findings suggestive of carcinoma include shorter disease-free interval, higher serum levels of calcium and parathyroid hormone, and histologic appearance. Whether the locally recurrent parathyroid neoplasm is benign or malignant, aggressive surgery can control serum levels of calcium in these patients with acceptable rates of morbidity.

We developed a method for cAMP and cGMP immunocytology based upon fixation by microwave irradiation. Fixation by microwave irradiation prevented three problems found with other fixation methods: nucleotide loss from cells, nucleotide diffusion within cells, and chemical modification of immunologic epitopes. Six agonists (four that stimulate adenylate cyclase and two that stimulate guanylate cyclase) produced cAMP or cGMP accumulation patterns that were agonist-specific, dose-dependent, detectable at physiologic concentrations of hormone, and time-dependent within 15 sec to 30 min. cAMP accumulation after 1 mM forskolin was greatest in the nucleus. Isoproterenol, prostaglandin E2, or calcitonin caused initial accumulation of cAMP along the plasma membrane, but later accumulation was greater in the cytoplasm. With calcitonin the later accumulation of cAMP was selectively perinuclear and along the nuclear membrane. Sodium nitroprusside stimulated cGMP accumulation diffusely throughout the cytoplasm. Atrial natriuretic peptide initiated cGMP accumulation near the plasma membrane, and cGMP accumulation moved from there into the cytoplasm. In conclusion, microwave irradiation preserved cell structure and allowed visualization of expected as well as unsuspected changes in intracellular accumulation patterns of cAMP and cGMP.

Prior studies have given no evidence for regulation of vitamin D receptor (VDR) compartmentalization or subcellular organization. Microwave fixation (9-15 s) and an indirect immunodetection system of avidin-biotin enhancement and phycoerythrin fluorophore resulted in sufficient spatial and temporal resolution to allow analysis of these processes. We studied cultured fibroblasts from normals or from patients with four different types of hereditary defect compromising VDR function (mutant cells). Compartmentalization of VDRs in the absence of 1,25-dihydroxyvitamin D3 (calcitriol) was regulated by serum or estrogen. VDRs were mainly cytoplasmic in cells cultured without serum and phenol red, but VDRs were mainly intranuclear after addition of serum or an estrogen to cells for at least 18 h (slow regulation). Calcitriol initiated a rapid and multistep process (rapid regulation) of reorganization in a portion of VDRs: clumping within 15-45 s, alignment of clumps along fibrils within 30-45 s, perinuclear accumulation of clumps within 45-90 s, and intranuclear accumulation of clumps within 1-3 min. We found similar rapid effects of calcitriol on VDRs in various other types of cultured cells. These sequential VDR pattern changes showed calcitriol dose dependency and calcitriol analogue specificity characteristic for the VDR. In mutant fibroblasts VDR pattern changes after calcitriol were absent or severely disturbed at selected steps. Treatment of normal cells with wheat germ agglutinin, which blocks protein transport through nuclear pores, also blocked calcitriol-dependent translocation of VDRs. We conclude that immunocytology after microwave fixation provides evidence for regulation of VDR organization and localization.

Basic fibroblast growth factor (bFGF) is a potent endothelial cell mitogen found in a variety of normal and tumor tissues. Basic FGF lacks a classical signal sequence, and it is not clear how it is released from cells. bFGF or bFGF-like activity has not been previously demonstrated in plasma. In an earlier study we showed increased mitogenic activity for parathyroid-derived epithelial and mesenchymal cells in plasma of subjects with familial multiple endocrine neoplasia type 1 (FMEN1). In the present study we examined the growth-promoting activity of normal and FMEN1 plasmas [applied to heparin-Sepharose (HS) columns] in parathyroid-derived cloned endothelial cells. FMEN1 plasma HS-adsorbed activity exceeded normal plasma HS-adsorbed activity in 6 of 8 FMEN1 plasma samples. Peak (FMEN1 plasma) HS-adsorbed activity eluted with 0.1-0.3 M NaCl, was completely neutralized by specific antibodies against bFGF, and had an apparent mol wt of 110 kD. Active fractions from FMEN1 plasma prepared by gel filtration in 7 M urea displayed apparent mol wt of about 14-16 kD and showed increased apparent affinity for HS; recovered activity appeared principally in the 3.0-M NaCl eluate. Using a sensitive two-site immunoradiometric assay for bFGF we found 0.4 ng/mL bFGF-like immunoreactivity in the highly purified 3.0-M NaCl eluate from a HS column to which the active components from gel filtration of FMEN1 plasma in 7 M urea were applied. These results imply that bFGF or closely related factors circulate in FMEN1.

One variant of multiple endocrine neoplasia type 1 (MEN1) is defined by sporadic tumors of both the parathyroids and pituitary. The prevalence of identified MEN1 mutations in this variant is lower than in familial MEN1 (7% vs. 90%), suggesting different causes. Recently, one case of this variant had a germline mutation of p27(Kip1)/CDKN1B.The objective was to test p27 in germline DNA from cases with tumors of both the parathyroids and pituitary.Medical record review and sequence analysis in DNA were performed.This study involved an inpatient and outpatient referral program for cases of endocrine tumors.Sixteen index cases had sporadic tumors of two organs, both the parathyroids and the pituitary. There were 18 additional index cases with related features of familial tumors. Five subjects were normal controls. No case had an identified MEN1 mutation.Clinical status of endocrine tumors was tabulated. Sequencing of germline DNA from index cases and control cases for the p27 gene was performed by PCR.Endocrine tumor types and their expressions were measured, as were sequence changes in the p27 gene.Tumor features were documented in index cases and families. One p27 germline single nucleotide change was identified. This predicted a silent substitution of Thr142Thr. Furthermore, there was a normal prevalence of heterozygosity for a common p27 polymorphism, making a large p27 deletion unlikely in all or most of these cases.The MEN1 variant with sporadic parathyroid tumors, sporadic pituitary tumor, and no identified MEN1 mutation is usually not caused by p27 germline mutations. It is usually caused by as yet unknown process(es).