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Background: Functional imaging with 68Ga-DOTATATE PET-CT is widely employed to detect both primary and metastatic pheochromocytomas and paragangliomas (PGL), but its results may be occasionally misleading as in the case here reported. Case Presentation: We report here a 75-year-old woman with an interaortocaval PGL that was diagnosed after a hypertensive crisis occurring during the resection of a kidney tumor. 68Ga-DOTATATE PET-CT disclosed pathologic uptake in the abdomen and at the iliac crest. After the resection of the abdominal tumor, with the histological confirmation of PGL, arterial blood pressure and metanephrine levels were normalized. Genetic testing was negative. Thereafter, the bone lesion increased in size and became painful, requiring multiple medications. A selective biopsy disclosed a metastatic lesion arising from the renal tumor. Conclusion: The false-positive result of 68Ga-DOTATATE PET-CT is discussed.

A 24-years old female was admitted for acute renal failure, melanoderma, hyponatremia, and hyperkalemia. The clinical suspicion of Addison’s disease was confirmed by laboratory test and the appropriate replacement therapy with corticosteroids and fludrocortisone was started. In the meantime primary hypothyroidism and diabetes mellitus type 1 were disclosed and treated, thus fulfilling a diagnosis of autoimmune polyendocrine syndrome type 2. Eighteen months later she was admitted for right-sided heart failure. The work-up allowed to diagnose pulmonary arterial hypertension. Here, we report the clinical course and discuss the putative link between these two rare diseases.

Summary We describe the 20-year course of a 63-year-old male with a macroprolactinoma that acquired resistance to treatment and aggressive behavior after a 4-year successful treatment with cabergoline. He was submitted to multiple surgical resections by a skilled surgeon, fractionated radiotherapy and was eventually treated with temozolomide. After a first 6-month standard cycle, a relapse occurred and he was treated again successfully. Learning points: Prolactinomas are the most frequent type of pituitary adenoma. They usually have a benign course. In most cases dopamine-agonist drugs, mainly cabergoline, are first-line (and usually only) treatment. Occasionally prolactinomas can have or acquire resistance to treatment and/or aggressive behavior. Temozolomide (TMZ), an oral alkylating drug, can be effective in such aggressive tumors. Multimodal treatment (surgery, radiation, cabergoline and TMZ) is warranted in aggressive pituitary tumors. We describe here successful rechallenge with TMZ after relapse occurring 18 months after a first TMZ cycle.

A 69-year-old male was admitted for severe hyponatremia disclosed after an accidental fall. He was anticoagulated from 2 months after the implantation of a biologic aortic valve prosthesis. The work-up disclosed adrenal failure and MRI showed bilateral adrenal hemorrhage. Clinical picture and lab parameters normalized quickly after the appropriate replacement treatment. Anticoagulation excess should be added to the list of drugs potentially causing hyponatremia. Learning points: Hyponatremia requires a complete and timely workup in order to start an appropriate treatment for the improvement of clinical conditions. History is crucial: a detailed list of drugs potentially causing hyponatremia should be collected. Anticoagulants should be added to the list, mostly in the event of excessive anticoagulation. Intra-adrenal hemorrhage is a rare cause of hyponatremia and adrenal failure. The ACTH test is still the gold standard for the diagnosis of hypoadrenalism. Background Hyponatremia is a frequent event in elderly inpatients that requires a complete workup for the establishment of diagnosis and the start of an appropriate causal treatment (1). In the management of hyponatremia, it is of utmost importance to discriminate the time course, i.e. an acute vs chronic onset, and then to avoid two main errors: a delay in treatment and an overzealous rapid correction, causing hyponatremic encephalopathy and osmotic demyelination syndrome, respectively, both with an ominous prognosis (2, 3).

Background: Metyrapone is a steroidogenesis inhibitor approved in Europe for the treatment of endogenous Cushing’s syndrome (CS) based on observational retrospective studies published over more than 50 years. We present data from the first prospective study designed to confirm metyrapone efficacy and good tolerance in patients with CS. Methods: This single arm, open-label, multicenter, international trial enrolled 50 patients with CS who had three baseline 24 hours urine free cortisol (UFC) values at least 50% above the upper limit of normal (ULN=165 nmol/24h). Metyrapone was titrated over 12 weeks (W12) to achieve normal urine (mean of 3 values, mUFC) and serum cortisol levels. Patients whose mUFC did not exceed 2-fold the ULN could enter a 6-month extension period. The primary efficacy endpoint was the proportion of patients with mUFC ≤ ULN at W12 assessed in a central laboratory using LC-MS/MS. The most important secondary endpoint was mUFC decrease of ≥ 50% at W12. Results: At baseline: mean age was 47 years, median mUFC (range) was 570 (291 - 8476) nmol/24h (3.5 x ULN). Hypercortisolism was in 96% of patients either moderate (mUFC ≥ 2xULN; < 5x ULN) in 63% or severe (≥5 x ULN) in 33%. Hypertension (69%) and diabetes mellitus (47%) were the most common comorbidities. At W12: 47% (23/ 49) met primary endpoint. Another 40% (19 / 49) had mUFC ≤ 2xULN. Median percentage decrease in mUFC from baseline to W12 was -74%. Secondary endpoint was met by 80% of patients who had a mUFC decrease of 50%. Final median metyrapone dose was 1500 (250; 5500) mg/day. Physical signs and symptoms were normalized or improved in 66% of patients. Circulating cholesterol, HbA1C and fasting glucose and insulin improved with median decrease of 12%, 3%, 5% and 9% respectively and median systolic and diastolic blood pressure also decreased by 4 and 5mmHg respectively. Among patients with antihypertensive treatments, 10 (31%) had a decrease in number of drugs and 5 (16%) had an increase in number of drugs during the study. Median ACTH increased by 11 % from baseline. Twenty six (52%) patients experienced mild to moderate study drug related adverse events (AEs). One patient discontinued before W12 because of an unrelated SAE on day 2 (pneumonia with septic shock). The most common AEs were nausea (24%), decreased appetite (18%), fatigue (14%), headache (10%), peripheral edema (6.0%), hypokalemia (6.0%) and hypertension (6.0%). Reversible adrenal insufficiency occurred in 6 (12%) patients. Few patients 14% (7/50) experienced at least one AE that led to a dose interruption or dose adjustment. Cushing Quality of Life Questionnaire increased of 10 points from baseline which is close to minimal clinically important difference = 10.1. Conclusions: This prospective study in patients with CS confirms that metyrapone effectively lowers UFC levels with a tolerability profile similar to the previously reported safety profile and improves QoL, at Week 12.

Simultaneous bilateral inferior petrosal sinus sampling (BIPSS) plays a crucial role in the diagnostic work-up of Cushing’s syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88–100% and 67–100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50–70%) makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres.

Key Clinical Message This case shows efficacy of low-dose pasireotide in biochemical and clinical control of severe hypercortisolism and in tumor volume reduction in a patient with an ACTH-secreting macroadenoma. The drug may be an option for long-term treatment in some patients where control of tumor mass is an important clinical endpoint.

About 35% of patients with pheochromocytoma/paraganglioma carry a germline mutation in one of the 10 main susceptibility genes. The recent introduction of next-generation sequencing will allow the analysis of all these genes in one run. When positive, the analysis is generally unequivocal due to the association between a germline mutation and a concordant clinical presentation or positive family history. When genetic analysis reveals a novel mutation with no clinical correlates, particularly in the presence of a missense variant, the question arises whether the mutation is pathogenic or a rare polymorphism.We report the case of a 35-year-old patient operated for a pheochromocytoma who turned out to be a carrier of a novel SDHD (succinate dehydrogenase subunit D) missense mutation. With no positive family history or clinical correlates, we decided to perform additional analyses to test the clinical significance of the mutation.We performed in silico analysis, tissue loss of heterozygosity analysis, immunohistochemistry, Western blot analysis, SDH enzymatic assay, and measurement of the succinate/fumarate concentration ratio in the tumor tissue by tandem mass spectrometry.Although the in silico analysis gave contradictory results according to the different methods, all the other tests demonstrated that the SDH complex was conserved and normally active. We therefore came to the conclusion that the variant was a nonpathogenic polymorphism.Advancements in technology facilitate genetic analysis of patients with pheochromocytoma but also offer new challenges to the clinician who, in some cases, needs clinical correlates and/or functional tests to give significance to the results of the genetic assay.

Paragangliomas (PGLs) are rare neuroendocrine tumours. About 30-40 % of these tumours are mutated in one of the different susceptibility genes, including those encoding the different subunits of the succinate dehydrogenase, a complex involved both in the tricarboxylic acid cycle and in the oxygen transport chain. The aim of this work was to investigate whether SDHB mutations may account for alterations in cell metabolism and functions. Since human PGL cell lines are not available, we used the neuroblastoma cell line (SK-N-AS) stably transfected with the wild-type human SDHB or different SDHB-mutated constructs carrying some significant mutations found in our patients affected by PGLs. Similarly to succinate dehydrogenase (SDH)-mutated tumour cells, mutated SK-N-AS clones showed reduced SDH enzyme activity. All clones showed normal citrate synthase activity, reduced oxygen consumption and reduced carbonic anhydride production, thus demonstrating a decreased in mitochondrial metabolism. In two of the three mutated SK-N-AS, we also found an increase in HIF1α expression. Surprisingly and unexpectedly, in all the SDHB-mutated clones, we found a significant decrease in glucose uptake and in lactate culture medium concentration, suggesting also a decrease of cytosolic metabolism. Finally, we found that these energetic changes were associated to an increase in cell proliferation and migration. Overall, these data demonstrate that although SDHB mutations significantly downregulate both mitochondrial and cytoplasmic cellular metabolism, these mutations are associated to an upregulation of some cellular functions, such as growth rate and invasiveness.

Noradrenaline and adrenaline are the final mediators of sympathoadrenal activity. They exert complex direct and indirect actions on glucose metabolism. Increases in plasma catecholamines - as in patients with pheochromocytoma - as well as in sympathetic activity, causing increased noradrenaline release by the sympathetic nerve terminals, cause an increase in blood glucose. Patients affected by pheochromocytoma are often affected by glucose intolerance or diabetes which generally ameliorates or disappears after surgery. These patients are characterized by a condition of insulin resistance while plasma insulin concentrations may be decreased or increased, depending on the type of adrenergic receptor, α or β - which are preferentially activated by circulating catecholamines. Activation of adrenergic receptors may also derive from a chronic increase in sympathoadrenal activity which is present in various conditions (i.e. obesity) associated with type 2 diabetes. Experimental evidence suggests that sympathetic hyperactivity may be a pathogenic factor for type 2 diabetes as well as for the occurrence of diabetic complications. Interestingly, dopamine agonists, which exert multiple actions including a decrease in sympathetic activation, have recently been found to be of benefit in the treatment of type 2 diabetes.

Head and neck paragangliomas (HNPGLs) are neural crest-derived tumors. In comparison with paragangliomas located in the abdomen and the chest, which are generally catecholamine secreting (sPGLs) and sympathetic in origin, HNPGLs are, in fact, parasympathetic in origin and are generally nonsecreting. Overall, 79 consecutive patients with HNPGL were examined for mutations in SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, MAX, and TMEM127 genes by PCR/sequencing. According to a detailed family history (FH) and clinical, laboratory (including metanephrines), and instrumental examinations, patients were divided into three groups: a) patients with a positive FH for HNPGL (index cases only), b) patients with a negative FH and multiple HNPGLs (synchronous or metachronous) or HNPGL associated with an sPGL, and c) patients with negative FH and single HNPGL. The ten patients in group a) proved to be SDHD mutation carriers. The 16 patients in group b) proved to be SDHD mutation carriers. Among the 53 patients in group c), ten presented with germ-line mutations (three SDHB, three SDHD, two VHL, and two SDHAF2). An sPGL was found at diagnosis or followed up in five patients (6.3%), all were SDHD mutation carriers. No SDHC, SDHA, MAX, and TMEM127 mutations were found. In SDHD mutation carriers, none of the patients affected by HNPGL associated with sPGL presented missense mutations. In conclusion, a positive FH or the presence of multiple HNPGLs is a strong predictor for germ-line mutations, which are also present in 18.8% of patients carefully classified as sporadic. The most frequently mutated gene so far is SDHD but others, including SDHB, SDHAF2, and VHL, may also be affected.

Malignant pheochromocytomas/paragangliomas are rare tumors with a poor prognosis. Malignancy is diagnosed by the development of metastases as evidenced by recurrences in sites normally devoid of chromaffin tissue. Histopathological, biochemical, molecular and genetic markers offer only information on potential risk of metastatic spread. Large size, extraadrenal location, dopamine secretion,SDHBmutations, a PASS score higher than 6, a high Ki-67 index are indexes for potential malignancy. Metastases can be present at first diagnosis or occur years after primary surgery. Measurement of plasma and/or urinary metanephrine, normetanephrine and metoxytyramine are recommended for biochemical diagnosis. Anatomical and functional imaging using different radionuclides are necessary for localization of tumor and metastases. Metastatic pheochromocytomas/paragangliomas is incurable. When possible, surgical debulking of primary tumor is recommended as well as surgical or radiosurgical removal of metastases. I-131-MIBG radiotherapy is the treatment of choice although results are limited. Chemotherapy is reserved to more advanced disease stages. Recent genetic studies have highlighted the main pathways involved in pheochromocytomas/paragangliomas pathogenesis thus suggesting the use of targeted therapy which, nevertheless, has still to be validated. Large cooperative studies on tissue specimens and clinical trials in large cohorts of patients are necessary to achieve better therapeutic tools and improve patient prognosis.