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Synovial sarcoma (SS) is a soft-tissue malignancy that most often affects patients aged between 15 and 40 years, and the prognosis for patients with metastatic disease is generally poor. This study was performed to evaluate checkpoint blockade immunotherapy markers in SS, including tumor mutational burden (TMB), DNA mismatch repair (MMR) status, and PDL-1 (programmed cell death ligand 1), PD1 (programmed cell death 1), and CD8 expression by normal-tumor paired whole-exome sequencing (WES) and immunohistochemistry (IHC). Outcomes evaluated included event-free and overall survival. Twenty one (21) FISH (Fluorescence In Situ Hybridization)-confirmed SS cases (11 F, 10 M) were studied, with age ranging from 8 to 89 years at diagnosis and follow-up ranging from 1 to 16 years. TMB (n = 16) ranged from 0.83 to 212/Mb (median, 1.7). Only one case showed a high TMB of 212/Mb and missense variants of MMR genes in the primary tumor, while the other 15 cases had a low TMB of less than 5/Mb. IHC was performed on all 21 tumor samples for PD-L1, PD1, CD8, and MMR proteins. PD-L1 membranous staining was detected in 3 of 21 cases (14.3%), ranging from 1 to 5% for tumor proportion score and 1-10 for combined positive score. PD1 was detected in 15 of 21 cases (71.4%), ranging from 1 to 25/HPF (high power field) (median, 2). CD8 stain was seen in all cases, ranging from 2 to 60/HPF (median, 5). PD1 staining results correlated with CD8 staining results (P 0.0001). No correlation of TMB or IHC markers was found with survival. No fixed pattern of TMB or IHCs between primary and metastatic tumors was observed; there was no correlation between TMB or IHCs and age, location, or diagnosis subtype. All of the cases tested showed retained expression of MMR proteins. The results show that for SS, a tumor with strong driver translocation, most cases have a low TMB, but occasionally a high TMB may be present, as observed in 1 of the 16 (6.25%) cases. The demonstration of a subgroup of SS cases with high TMB might explain the 10% response rate to checkpoint immunotherapy observed in clinical trials in patients with SS.

Tumor-infiltrating lymphocytes (TILs) in primary melanomas are thought to represent the host antitumor immune response, but controversy exists over whether TILs offer independent prognostication of survival. We studied a cohort of 1241 patients with primary melanoma to assess the association of absent, nonbrisk, and brisk TIL grade with survival outcomes. We tested whether quantitative TIL counts using immunohistochemical lymphocyte markers CD3, CD45, and FOXP3 add prognostic value to TIL grading compared with histology alone in 15% of the cohort. To assess for intergroup immunologic heterogeneity among TIL grades, we investigated differential expression of 594 immunoregulatory genes in 67 primary melanomas. On histologic evaluation of 1241 primary melanomas, TILs were graded as absent (n=388, 31%), nonbrisk (n=330, 27%), and brisk (n=523, 42%). Patients with brisk TILs had improved recurrence-free survival (P=.025) and overall survival (P=.006) compared with patients with nonbrisk and absent TILs, for which there were no differences in recurrence-free survival (P=.40) or overall survival (P=.41). TIL quantitation by immunohistochemistry did not improve prognostication compared with TIL grading on hematoxylin and eosin-stained sections. Melanomas with nonbrisk and absent TILs share similar immunoregulatory gene expression profiles. In contrast, melanomas with brisk TILs demonstrate upregulation of T-cell activation pathways and inhibition of upstream immune checkpoint regulators. The presence of TILs in primary melanomas represents a heterogeneous group, and caution in prognostic interpretation is warranted. Melanomas with brisk TILs are defined by an immunostimulatory gene expression profile and improved prognosis compared with melanomas with nonbrisk or absent TILs.

Summary Cherubism is a rare genetic disease characterized by bilateral giant cell reparative granuloma of the jaws consisting of a fibrotic stroma with giant multinucleated cells (GMCs) and osteoclastic features. Cherubism severity is highly variable, and recurrence after surgery is the most important risk. Currently, there are no prognostic indicators. The aims of this study were to evaluate the osteoclastogenesis phenotype by histologic examination of nuclear factor of activated T cells 1 (NFATc1) localization and tartrate-resistant acid phosphatase (TRAP) activity and to correlate the results to disease aggressiveness to define prognostic indicators. Based on cherubism evolution 1 year after surgery, 3 classes of cherubism aggressiveness were identified: mild (group A), moderate (group B), and severe (group C). Histologically, in grade A and B cherubism lesions, GMCs were negative for both TRAP activity and NFATc1 nuclear localization. In contrast, in grade C cherubism lesions, GMCs were all positive for TRAP activity and NFATc1 nuclear localization and displayed osteoclast-like features. Other histopathologic findings were not different among the 3 groups. Our results establish that TRAP activity and NFTAc1 nuclear localization are associated with aggressive cherubism and therefore could be added to routine pathologic examination to aid in prognosis and management of the disease. The finding of NFATc1 nuclear localization in aggressive tumors supports the addition of anticalcineurin treatment to the therapeutic arsenal for cherubism.

An 80-year-old white man underwent pylorus-preserving pancreaticoduodenectomy after presenting with obstructive jaundice and a dilated biliary tree on cholangiopancreatography. Histologic evaluation of the specimen revealed synchronous autoimmune pancreatitis (lymphoplasmacytic sclerosing pancreatitis) and infiltrating ductal adenocarcinoma of the pancreas. The mixed inflammatory infiltrate centered on the pancreatic ducts was associated with acinar loss, parenchymal fibrosis, and obliterative venulitis. Immunohistochemical labeling with an antibody to IgG4 revealed greater than 50 IgG4-positive plasma cells per high power field. Although not appreciated grossly, pancreatic intraepithelial neoplasia-3 and a neurotropic infiltrating poorly differentiated adenocarcinoma of the pancreas were also present. This case highlights the importance of carefully evaluating patients with autoimmune pancreatitis to rule out an underlying neoplasm and the importance of following those who were treated nonsurgically until the disease fully resolves.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. GISTs express KIT and show gain-of-function KIT mutations. Most of these mutations affect the KIT juxtamembrane domain, but other KIT domains are mutated at a lower frequency. In this study, frequency of GCC TAT insertion mutation (1530ins6) in KIT exon 9 (extracellular domain) and its possible clinicopathologic significance was investigated. Screening of 520 GISTs identified 26 cases with 1530ins6 KIT mutation and confirmed the previously reported low frequency of this type of KIT mutation among GISTs of different locations. Of the 26 tumors with 1530ins6 KIT mutation studied, 21 originated from the small intestine, 1 from the colon, and 3 from the rectum. In 1 case, primary small intestinal versus colonic localization could not be clearly established because of intra-abdominal dissemination. No distinctive morphological features were identified for the cohort of tumors defined by 1530ins6 KIT mutations. Most of the tumors showed predominant spindle cell morphology, and a few cases had epithelioid or pleomorphic histological features. Following previously published criteria based on tumor size and mitotic rate, 22 of 26 (85%) tumors were classified as malignant or potentially malignant, and 4 (15%) were classified as probably benign. A malignant clinical course was documented in 18 of 19 tumors from the malignant category. The survival times of 11 patients who died of disseminated GISTs ranged from 1 month to 105 months (median survival time, 26 months). In contrast, 2 of 4 GISTs assigned as probably benign tumors with follow-up information had long disease-free survival. GISTs carrying 1530ins6 occur exclusively in the intestinal location, and a great majority of these tumors follow a malignant course.

Synovial sarcoma, which has a wide spectrum of biologic behavior, warrants accurate grading to assess the patient's prognosis. We studied the clinicopathologic and immunohistochemical features of 44 cases of synovial sarcoma in patients treated primarily or secondarily at the National Cancer Center, Tokyo, to identify independent prognostic factors. There were local recurrences in 16 patients (36%), and 25 (57%) developed metastases, primarily to the lungs. The estimated cumulative 5-year and 10-year survival rates were 68% and 41%, respectively. Variables associated with an adverse outcome included tumor size > 6.7 cm; initial treatment outside the National Cancer Center; poorly differentiated subtype; high nuclear atypia; mitosis count > 27/10 high-power fields; tumor necrosis; absence of stromal calcification; nuclear expression of beta-catenin, which was found in 25 cases (57%); Ki-67 (MIB-1) index > 27%; and histologic grade 3. Nuclear accumulation of beta-catenin as a cell-signaling event may play an important role in the progression of synovial sarcoma and therefore might be predictive of short survival. However, multivariate analysis clearly showed that only histologic grade, as defined by using categorized variables for the MIB-1 index and tumor necrosis, was an independent prognostic factor. Most variables were correlated with lung metastasis and histologic grade. High-grade synovial sarcoma assessed by a histologic grading system based on the proliferative activity of the neoplastic cells can be viewed as high risk with the patients most likely to die of disease within 10 years after surgery and in need of improved chemotherapy. HUM PATHOL 32:257-263.

Five hundred consecutive breast carcinomas from the first screening round of the Breast Cancer Detection Demonstration Project were studied quantitatively and semiquantitatively for features relevant to the diagnosis of tubular carcinoma. Tubularity was defined as the proportion of tumor cells that were adjacent to an open lumen. Nuclear morphology and mitotic activity were graded 1 to 3, and the presence of apocrine snouts as absent, few, common, or prominent. In plots and statistical cluster analysis, tubular carcinoma appears as part of a continuous spectrum of morphologies and not as a distinct entity. In multivariate analysis, apocrine snouts had no significant association with either nodal status or deaths of breast cancer. Tumors with 70% or greater tubularity by our definition and mitosis and nuclear grades 1 were not associated with either nodal metastases or deaths of breast cancer. The question is raised whether tubular carcinoma at the benign end of a spectrum shades into benign glandular proliferations, with particular reference to microglandular adenosis. A uniform and precise definition of tubularity is needed for the attainment of sufficient collective experience to delimit tubular carcinoma both from more aggressive carcinomas and from benign proliferations.

Predicting tumor behavior in meningiomas based on histology alone has been problematic. This study retrospectively compares histology and MIB-1 (cell proliferation marker) labeling indices (LI) in benign, aggressive, and malignant meningiomas. Six histological features, including mitoses, necrosis, loss of pattern, hypervascularity/hemosiderin deposition, prominent nucleoli, and nuclear pleomorphism, were compared in 90 meningiomas (Fisher's exact test). Tumors with two or more of the above features were designated as aggressive meningiomas. Malignant meningiomas were characterized by brain invasion or metastasis. The MIB-1 LIs (% positive tumor cell nuclei) were compared between the three groups (Kruskal-Wallis test, Wilcoxon two-sample test). Of the benign meningiomas (n=37; mean age, 54 years), 41% had one of the six histological features, with nuclear pleomorphism (n=10) being the most frequent. The aggressive tumors (n=29; mean age, 61 years) were characterized by nuclear pleomorphism (n=28), mitoses (n=20), necrosis (n=16), loss of pattern (n=16), prominent nucleoli (n=6), and hypervascularity/hemosiderin deposition (n=5). Malignant tumors (n=24; mean age, 59 years) were characterized by nuclear pleomorphism (n=22), mitoses (n=21), loss of pattern (n=21), necrosis (n=21), nucleoli (n=17), and hypervascularity/hemosiderin deposition (n=3). Significant differences were found between the aggressive and malignant groups with regard to loss of pattern, necrosis, and nucleoli (P=.0043, .011, and .00029, respectively). Mean MIB-1 LIs for the benign, aggressive, and malignant groups were 1.0% (range, 0 to 5.5%),5.5% (range, 0.1 to 32.5%), and 12.0% (range, 0.3 to 32.5%), respectively. Differences in the mean MIB-1 LI between groups were statistically significant, with P values of

The mitotic index (MI) and the Ki-67 labeling index (LI) are both understood to measure cellular proliferation, but their relationship is poorly defined. We determined the mitotic index in hematoxylin and eosin-stained paraffin sections of 189 consecutive carcinomas and performed immunohistochemistry on sections from the corresponding blocks using the Ki-67-specific monoclonal antibody Ki-S5. The distributions of MI and LI in the entire series were clearly different, the former fitting a Poisson function in contrast to a broad-tailed unspecific distribution of the latter. Both indices were closely correlated in mammary carcinomas and non-small cell lung cancers, and to a slightly lesser extent in colorectal adenocarcinomas. No significant association was found in small cell lung cancers. In squamous cell carcinomas, the two parameters were inversely correlated. A good agreement between MI and LI values was observed in well-differentiated and moderately well-differentiated cancers regardless of their histological type, whereas in poorly differentiated carcinomas the correlation was not significant. We conclude that MI and LI measure different proliferation characteristics. Their relationship appears to depend on the tumor type and the degree of differentiation. Rather than artifacts due to processing or evaluation techniques, specific differences in cell cycle kinetics are likely to account for these discrepancies.

Typical and atypical carcinoids (TC, ATC) and small (SCLC) and large cell neuroendocrine carcinomas (LCNEC) constitute the spectrum of neuroendocrine lung tumors. Chromosomal aberrations have not been studied in LCNEC and only rarely in carcinoids. Only SCLCs have been investigated frequently for chromosomal aberrations. We compared three typical and four atypical carcinoids, one atypical carcinoid/SCLC mixed type, three SCLC, and three LCNEC for chromosomal gains and losses using comparative genomic hybridization. Typical carcinoids showed either no changes or only few chromosomal gains. Atypical carcinoids appeared genetically heterogeneous: One case had no aberrations, and three cases had few aberrations; two of them showed a deletion of 11q. SCLC and LCNEC were characterized by many gains and losses, especially similar changes of 3p, 5q, 5p, and 13q. Although ATC resemble LCNEC morphologically, there were no similarities at the genetic level. We have found a reciprocal relationship of prognosis and the amount of aberrations. TCs and ATCs with few chromosomal changes have the best prognosis, whereas SCLCs and LCNECs were generally characterized by a great amount of aberrations and worst prognosis. There was no unbalanced aberration common in all types of neuroendocrine tumors of the lung.

Hemangiopericytoma (HPC) is an uncommon vascular neoplasm thought to be derived from pericytes. Prediction of patient outcome is difficult based what is currently known about these tumors and histological parameters alone. We compiled 27 cases of HPC and evaluated the spectrum of histological features to investigate whether there was any correlation between histology, immunostaining, prognostic markers, and patient outcome. The following parameters were evaluated: vasculature, histological pattern (solid, myxoid, trabecular, alveolar), degree of cellular pleomorphism, necrosis, mitoses, and giant cell content. Immunohistochemistry was performed to determine the reactivity for CD 31, CD34, vimentin, actin, cytokeratin, S100, actin, and SMA. Proliferative rate was analyzed using antibodies to PCNA and MIB1. Patient's age ranged from 8 months to 75 years (mean, 35; median, 31). Twenty of 27 cases were located in the extremities. The tumors were grossly described as lobulated and well circumscribed (n=12) and nonencapsulated (n=15). By histology, the characteristic ramifying or staghorn vasculature pattern was seen in all cases. A solid histological pattern was mixed with an alveolar pattern in three cases, trabecular pattern in six cases, and myxoid pattern in two cases. Tumor cells were uniform, polygonal to spindle-shaped, often with vesicular nuclei. Tumor giant cells were present in 9 of 27 cases; necrosis, in 11 of 27. Mitoses ranged from 0 to 14 per 10 high-power fields (HPF). Cellular pleomorphism was 1+ in nine cases, 2+ in 12 cases, and 3+ in six cases. Immunohistochemistry showed reactivity for CD34 and vimentin in all cases. Actin was focally positive in one case, and SMA was focally positive in another. CD 31, cytokeratin, and S100 were uniformly nonreactive. Proliferative index measured by PCNA and MIBI ranged between less than 1% and 40% of tumor cells. Follow-up was available in 22 cases and ranged from 1 year to 15 years. Seven patients had metastases, and two recurred locally. Thirteen patients had no evidence of disease at last checkup. Parameters associated with recurrences or metastases include a trabecular pattern, the presence of necrosis, mitoses, vascular invasion, and cellular pleomorphism. Features associated with an aggressive biological behavior can be identified histologically. There was some, but not total, correlation between proliferative markers and tumor aggressiveness.

Metastatic uveal melanoma is profoundly chemoresistant and has a very poor outcome. We have previously shown that the MDR1 gene and its gene product P-glycoprotein (P-gp), which are known to cause drug resistance in cancer cells, are expressed in ocular melanoma. Overexpression of MDR1 has been associated with a poor survival in some tumor types treated by chemotherapy and in some untreated tumours. To assess whether MDR1 expression is of prognostic value in uveal melanoma, we evaluated the expression of MDR1 by immunohistochemistry in 108 cases. Three semiquantitative grades were used to evaluate positive staining. We detected MDR1 expression in 80% of cases; 28% showed grade I staining; 30%, grade II staining; and 22%, grade III staining. There was a statistically significant association ( P = .004) between MDR1 expression by tumor cells and shorter survival times ( n = 96), which was most striking at grade III levels of expression. Multivariate analysis showed that MDR1 expression is an independent prognostic indicator of poor survival. We conclude that (1) MDR1 may be involved in chemoresistance and tumor propagation in primary uveal melanoma, and (2) increasing levels of expression are prognostically significant and may prove a useful marker of tumor invasiveness, independent of established prognostic factors.

Immunohistochemical expression of p53, Bc12, vimentin, and S100 protein-positive Langerhans cell was evaluated in 50 endometrial carcinomas (6 stage I, 14 stage II, 20 stage III, and 10 stage IV), in an attempt to use these markers as predictors of survival. Monoclonal antibodies to p53, Bcl-2, vimentin, and S100 proteins were applied to paraffin-embedded sections of endometrial adenocarcinoma, using the avidin-biotin peroxidase complex technique (ABC). All 20 patients with stage I and II carcinomas were alive with a mean follow-up of 3 years. Of 30 patients with stage III and IV carcinomas, 13 died of tumor (3-year survival, 57%; SE, 10%), eight were alive with tumor, and nine were alive with no evidence of tumor (mean follow-up, 46 months). Strong p53 positivity was present in 11 carcinomas (22%), including nine high-stage and two low-stage tumors. Bcl-2 positivity was identified in 33 tumors (66%). These tumors were mostly low stage; however, no correlation was found between Bcl-2 expression and prognosis. Vimentin positivity (P.001), and tumor infiltration by a large number of S100 protein-positive Langerhans cells (P.05) were associated with low-stage tumors. Vimentin was expressed in 23 carcinomas, including 70% of low-stage tumors and 20% of high-stage tumors. Most high-grade carcinomas were Langerhans cell depleted; most low-grade carcinomas showed50 S100 protein-positive Langerhans cells/10 high-power fields. Our results indicate that Langerhans cell infiltration and vimentin positivity of tumor cells are favorable prognostic factors in endometrial carcinomas.

The aim of this study was to investigate the expression of bcl-2, p53 oncoproteins, and Ki-67 antigen in a series of transitional cell bladder carcinomas and its relation to the traditional prognostic indicators and patient's survival. One hundred six cases with transitional cell carcinoma (TCC) were examined for detection of bcl-2, p53 proteins, and Ki-67 antigen (MIB1 antibody). Bcl-2 immunohistochemical positivity was observed in 52% of TCCs and in 57% of low-grade and 44% of high-grade TCCs. Bcl-2 was also detected in normal urothelium and dysplastic lesions with basal cell expression, and negative staining was observed in carcinomas in situ. Tumor stage showed a significant inverse correlation with overall bcl-2 positivity. The loss of bcl-2 protein expression in higher-stage TCCs was statistically significant (Pt = .01). p53 protein was overexpressed in 50% of TCCs and more frequently in invasive and in carcinomas in situ than in superficial TCCs (Pt = .03). In contrast, detection of p53 was not observed in normal and dysplastic urothelium. p53 positivity was related to the degree of differentiation and to the stage of the disease (Pf = .01 and Pt = .03, respectively). Concerning Ki-67 antigen, its expression was found in 57.5% of TCCs. There was a strong overall correlation of Ki-67 with tumor stage (Pt = .002) and grade (Pf = .002). Univariate statistical analysis showed that the expression of p53 and Ki-67 was significantly correlated to poor prognosis (P = .02, P = .02, respectively). On multivariate analysis, none of these markers but only stage and grade were significantly correlated to prognosis (P = .02, P = .02, respectively). These findings suggest that overexpression of bcl-2 protein may be an early event in tumorigenesis. Tumors with loss of bcl-2 positivity and overexpression of p53 and Ki-67 had an unfavorable prognosis; however, in multivariate analysis, they had no independent prognostic value.

The DNA content and proliferative index of 61 gastrointestinal stromal tumors (GIST) were measured by image analysis and correlated with the lesion's clinicopathological features and patient's survival. DNA analysis was performed on cytospin single-cell preparations obtained from the paraffin-embedded tissue blocks. MIB-1 was the proliferation marker used on paraffin sections. DNA aneuploidy was detected in 12 tumors (18%), and high MIB-1 index (22%) in 12 lesions (18%). DNA aneuploidy and high MIB-1 index statistically correlated with high mitotic rate (or = 5 x 10 high-power field [HPF]) (P.001) and with the presence of necrosis (P.05). The patient's survival was significantly correlated with DNA ploidy (P.01), MIB-1 index (P.00001), mitotic rate (P.00001), presence of necrosis (P.0001), and size of the tumor (P.01). Multivariate regression analysis showed that only MIB-1 index was an independent parameter in predicting the clinical outcome for patients with GIST. The mitotic rate was the only other independent prognostic factor when MIB-1 index was not allowed to enter the model.

Thirty-nine mammographically detected, (M-detected) small invasive carcinomas of the breast (or = 5 mm) were compared with 78 consecutive clinical cancers (or = 10 mm) for a variety of morphological and biological markers of prognostic importance. There were more tubular carcinomas in the M-detected group (12.8% v 3.8%), but this did not reach statistical significance. Incidences of other histological types were similar. The types of associated in situ component were similar in the two groups. M-detected cancers were of lower overall grade (P.001), lower architectural and nuclear grades (P = .0164 and P.0001 respectively), and had fewer mitotic cells (P.0001). None showed positive lymph nodes (P.0001). Estrogen and progesterone receptor expression was similar in both groups. M-detected cancers expressed p53 nuclear protein less frequently than clinical cancers (P = .0398), had lower levels of microvessel density (P = .0001), and were more often diploid (P = .0131). S-phase of diploid tumors in the two groups was similar, but S-phase of aneuploid tumors was lower in the M-detected group (P = .0057). Ki67 expression was lower in M-detected cancers (P.0001). In conclusion, M-detected small breast cancers, although invasive, represent an evolutionary phase of breast cancer that generally lacks morphological and biologic markers of aggressive behavior. The presence or absence of these markers, collectively, may explain the influence of tumor size on survival in patients with breast cancer.

The mitotic index (MI) is the most commonly used quantitative measure in anatomic pathology but has been widely criticized for supposed “irreproducibility.” In this article, the authors show that mitotic figure (MF) counts may be described by a Poisson distribution, give confidence intervals for the MI, and show that the supposed irreproducibility is largely a consequence of the counting techniques. They also show how to obtain the MI to a predetermined level of precision and present an analysis of why mitotic figure counting works, when properly used, despite the inherently low precision of the estimates that are usually obtained.

Grading of tumor malignancy in breast cancer should contribute essential information both for the prospective outcome of the individual patient as well as for TNM staging. In a series of 104 breast cancer patients we tested the prognostic validity and reproducibility of mitotic figure counting compared with TNM staging, Bloom and Richardson grading, DNA single cell cytometry, and morphometry. Four-micrometer thick hematoxylin-eosin-stained routine slides were investigated. Mitotic figures were counted in representative areas of the tumor in 10 159-μm 2 —sized high power fields (HPFs) at a 400× magnification; the median value was seven and the threshold for the 25th percentile was three. This value should replace the common but prognostically invalid threshold of 10. Univariate survival analysis showed that mitotic figure counting allows the identification of three groups of patients (⩽3, 4 to 20, >20 mitoses per HPF) with significantly different survival probabilities ( P P = .0178). Depending on the number of mitotic figures, length of survival was significantly different within the group of TIN0 tumors ( P = .0082) and the group of T1N1 or T2N0 tumors ( P = .0251). In a Cox stepwise regression model mitotic frequency counting added prognostic information to tumor size and was of higher prognostic significance than lymph node status, DNA ploidy, or mean nuclear area. The 95% confidence limit for interobserver reproducibility, tested in 20 cases, was plus/minus 8 mitoses. After quartilization an agreement of 75% was observed.

Benign metastasizing leiomyoma (BML) is a rare condition, characterized by the occurrence of multiple smooth-muscle nodules, most often located in the lung after previous hysterectomy because of histologically benign appearing leiomyoma. Although the condition resembles a metastatic process, case studies provided evidence that it may be the result of an intravenous leiomyomatosis or an independent and multifocal smooth-muscle proliferation. Comparative genomic hybridization and X-chromosome inactivation analysis were used in a case of BML to determine whether pulmonary and uterine tumors are related one to another. A balanced karyotype, previously reported in leiomyomas and an identical X-chromosome inactivation pattern found in all tumorlets, is most consistent with a monoclonal origin of both uterine and pulmonary tumors and the interpretation that pulmonary lesions are metastatic.

Primary synovial sarcoma (SS) of the lung is rare and may create diagnostic challenges. We reviewed 11 cases of pulmonary SS (PSS) confirmed by the presence of a tumor-specific SYT-SSX fusion gene to verify their clinicopathologic features including immunohistochemical and genetical profiles. The tumors occurred in 4 men and 7 women (age 29 to 81 years; mean age, 58; median age, 50), and ranged in size from 2 to 15.5 cm (mean, 9 cm). Of the 11 tumors, 10 were a monophasic fibrous type and 1 was a poorly differentiated type. Mitotic rate ranged from 8 to 43 per 10 high-power fields. All cases showed at least focal immunohistochemical positivity for AE1/AE3, CAM5.2 and/or epithelial membrane antigen. High proliferating cell nuclear antigen labeling index (>20%) was found in 8 of 10 cases (80%). Eight (90%) of 9 cases were negative for E-cadherin, and 1 case (10%) exhibited reduced expression of the molecule. The aberrant expression of beta-catenin within cytoplasm and/or nuclei was observed in 6 of 9 (67%) cases. SYT-SSX1 and SYT-SSX2 fusion gene transcripts were detected in 9 and 2 cases, respectively. In 10 patients with follow-up, 3 (30%) had local recurrences, and 4 (40%) developed distant metastases. Five (50%) patients died of the tumor 1 to 9 years after surgery, and 5 (50%) were alive and disease-free in the period ranging from 3 months to 5.5 years. In conclusion, PSS tends to occur in older patients and shows an aggressive behavior probably due to its anatomical location and large tumor often resulting in incomplete resection and high proliferative activity.

The proliferative activity is one of the most important single prognostic parameters in breast cancer diagnosis and the time-honored measure of proliferative activity, the mitotic figure count, is an integral component of most combined prognostic scores. The detection of the cell cycle-specific antigens Ki-67, and the development of anti-Ki-67 antibodies, including the paraffin-reactive antibody MIB-1, have established immunohistochemical detection of cell cycle-specific antigens as a measure of proliferative activity in breast cancer diagnosis. The current study was performed to correlate mitotic figure counts with the proliferative activity as assessed by MIB-1 immunohistochemistry, taking into consideration the interobserver reliability of 5 pathologists in estimating mitotic figure counts. In 32 consecutive invasive ductal breast carcinomas, mitotic figure counts were performed independently by 5 pathologists. Mitotic activity was expressed as number of mitotic figures per 10 high-power fields and in a 3-tier score according to the Scarff Bloom Richardson system. Immunohistochemistry was performed using MIB-1 antibody, heat-induced epitope retrieval, and the standard avidin-biotin-immunoperoxidase method. MIB-1 immunohistochemistry was assessed in 3 representative 20 × fields by semiquantitative estimation (% of tumor cells positive) and by image analysis (number of MIB-1-positive cells/mm 2 ). We found a high degree of interobserver correlation among 4 experienced pathologists, in both mitotic figures per 10 high-power fields and the 3-tier scoring system. We observed significant, albeit weak, correlations between semiquantitative and quantitative MIB-1 immunohistochemistry and the number of mitotic figures per 10 high-power fields ( r between .36 and .53), but this significance was lost in 3 of the 5 observers when mitotic activity was expressed in the 3-tier scoring system. This study confirms mitotic figure counting in the hands of experienced pathologists as a valid, reproducible means of assessing proliferative activity in routine breast cancer diagnosis. The statistically significant, albeit only weak, correlation with MIB-1 immunohistochemistry is in agreement with results obtained by others and suggests that MIB-1 immunohistochemistry cannot be translated by a simple conversion factor into combined prognostic scores to replace the time-honored mitotic figure counts.

To perform a retrospective pilot study of the potential role of mast cells in acute and chronic rejection of the lung allograft, transbronchial biopsies of 29 patients with acute rejection and six patients with bronchiolitis obliterans were stained with antibodies to mast cell tryptase. The number of mast cells per unit area were counted, and compared with a control group of normal lung biopsies stained in a similar fashion. Increasing grades of acute rejection were associated with progressively more mast cells per high-power microscopic field. The presence of bronchiolitis obliterans was accompanied by the greatest numbers of mast cells. Mast cells may play a role in the acute rejection response to the lung allograft and in the development of bronchiolitis obliterans.

Gastrointestinal autonomic nerve tumor (GANT) is a specialized form of stromal neoplasm whose ultrastructural features support a myenteric plexus derivation and provide the basis for its diagnosis. GANT actual frequency, relationship to skeinoid fibers, and CD34 expression status are some of the controversial aspects of this entity. Out of 14 gastrointestinal stromal tumors gathered during a 1-year period, six (42%) instances were diagnosed as GANT by electron microscopic study of at least five ultrathin sections per case. Additionally, GANTs were immunohistochemically investigated with a panel of nine antibodies including CD34. Ultrastructurally, every GANT case showed diagnostic findings and evidence of skeinoid fibers, whereas immunohistochemically all except one were CD34 positive. Immunoreactivity for neuron-specific enolase, synaptophysin, and vimentin was a common occurrence as well. In conclusion, GANT seems to be more frequent than hitherto recognized, skenoid fibers are a regular feature of GANT, and a positive CD34 immunoreaction does not discriminate between GANT and other non-smooth muscle, non-schwannian neoplasms.

Columnar cell carcinoma is a recently described variant of thyroid carcinoma that has been associated with an aggressive clinical course. The authors describe three new cases of columnar cell carcinoma occurring in two women and one man aged 62, 46, and 46 years, respectively. The tumors ranged in size from 1 to 7.5 cm, and two of the tumors were associated with distant metastases. One patient died of disease 39 months after presentation. Another patient is alive with distant metastases 27 months after diagnosis. One patient appears to be a long-term survivor with no evidence of metastasis after follow-up of 22 years. This patient had a tumor that was small (1 cm) and encapsulated. DNA ploidy analysis in two tumors showed diploid DNA content, and there was no elevated S phase. All tumors were positive for thyroglobulin and negative for calcitonin and carcinoembryonic antigen (CEA). These findings support the original observation that columnar cell variants of papillary thyroid carcinoma are usually aggressive neoplasms. There does not appear to be an increased incidence of DNA aneuploidy in columnar cell carcinomas to account for their more aggressive behavior. These tumors occur over a wide age range, can metastasize widely, and are not usually responsive to radioactive iodine or chemotherapy.

Ovarian granulosa cell tumors (GCTs) behave unpredictably. Stage I patients suffer recurrences many years after treatment, and histopathologic evaluation of the primary GCT offers only a few clues. Grading, in particular, is largely ineffective. Ki67 (MIB-1) and p53 monoclonal antibodies (active on paraffin embedded tissues) provide insight into nuclear proliferation and control, respectively. In this study, the authors hypothesized that these molecular markers will help predict the clinical behavior of GCTs. Paraffin sections from 68 GCTs (arising in 56 patients: 53 primary and 15 recurrent) including 34 typical and 27 diffuse adult, and seven juvenile types were immunostained for Ki67 (MIB-1 clone; Immunotech, Westbrook, ME) and p53 (DO7 clone; Novacastra Laboratories, UK). The Ki67 proliferation index (Ki67PI = percentage immunoreactive on a count of at least 400 nuclei) ranges from 1 to 50% (mean, = 12.2%; median, 9.3%). Nineteen percent of GCTs exhibited focal p53 immunoreactivity; the number of GCTs and proportion of nuclei decorated were as follows: four,1%; seven, 1% to 10%; and one, 20%. Ki67PI was higher in recurrent tumors (P.001) and correlated with mitotic rate (r = .75; P.0001). p53 staining was associated with juvenile type GCTs (P.001) and higher Ki67PI (P.005). Other histopathologic features exhibited no association with p53 staining or Ki67PI. Follow-up was available for 54 of 56 patients: 18 suffered recurrences after 16 to 229 months (mean, 72.1 months; median 59 months), and 36 were disease free 16 to 369 months (mean, 78.2 months; median, 70 months) after diagnosis. Curiously, high Ki67PI and mitotic rates of primary GCT correlated weakly with a disease-free course (P=.03 and .07 respectively). Disease recurrence was associated with stageI (P.0005), vessel invasion in the capsule (P.001), ruptured tumors (P.005), and older patients (P.02). p53 staining and size or subtype of GCT exhibited no prognostic value. For 12 patients, paired primary and first recurrence of GCT showed a striking increase in Ki67PI (P.00005) and mitotic activity (P.02) in the recurrence. p53 expression also appeared (de novo) in two recurrent GCTs. The interpretation of focal p53 staining (10% nuclei decorated in only one GCT) is controversial. Some investigators suggest that this represents overexpression of wild type p53 rather than p53 gene mutation. Primary GCTs exhibit a wide spectrum of proliferative activity, and the seven juvenile GCTs (the most proliferative type) demonstrated no recurrences in this study. Recurrent GCTs displayed a transformation of molecular markers to increased proliferative activity and overexpression of p53, fundamentally, by these markers, a different GCT than the primary one. These findings suggest a molecular basis for the lack of histopathologic predictors for recurrence. Factors other than proliferation of the primary GCT (which relates most closely to grading) either extrinsic to the neoplasm (host dependent) or as yet undetectable must determine malignant behavior.

Glycogenated hepatocyte nuclei are a common finding in liver biopsy specimens from patients presenting with a variety of clinical disorders. Most commonly, glycogenated nuclei from part of a spectrum of pathological changes in the diabetic or obese patient. However, no previous investigation has assessed glycogenated hepatocyte nuclei in a quantitative manner. In this study we used receiver operating characteristic (ROC) analysis to assess quantitatively the strength of glycogenated nuclei as a marker for diabetes and/or obesity. The study population consisted of 102 liver biopsy specimens from the adult population: 20 from diabetic patients, 41 from obese patients, 10 from both obese and diabetic patients, and 31 from neither diabetic nor obese patients. The mean age was 48.5 years with a range of 18 to 80 years. We evaluated the extent of glycogenated nuclei by averaging the number present per high power field over a minimum of 10 high power fields, representing all zones of the liver. The extent of steatosis was graded on a numerical scale from 1 to 10. In ROC analysis perfect tests are associated with an area of 1.0 and completely random tests with an area of 0.5. Receiver operating characteristic analysis showed that glycogenated nuclei are a relatively good test for distinguishing diabetic from nondiabetic patients (area, 0.75), a poor test for distinguishing obese from nonobese patients (area, 0.60), and a fair test for either condition (area, 0.67). In addition, we observed that glycogenated nuclei were preferentially distributed in the periportal "zone 1" of the liver, showed no correlation with steatosis, and had no relation to patient age. For our patient study population the prevalence of diabetes mellitus was 12%. At a cutoff level of four glycogenated nuclei per 400 x high power field, the specificity and sensitivity of glycogenated nuclei as a test for diabetes are 0.98 and 0.30, respectively, with a positive predictive value of 66%.