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Gonadoblastomas are composed of nests of neoplastic germ cells and sex cord derivatives surrounded by ovarian-type stroma. These tumors are found almost exclusively in persons with gonadal dysgenesis associated with a Y chromosome or Y chromosome fragment, and accordingly, the Y chromosome has been implicated in gonadoblastoma oncogenesis. To evaluate this association, we used two-color fluorescence in situ hybridization with chromosome-specific probes to determine the distribution of the X and Y chromosomes in the tumor nests and surrounding stromal cells in paraffin tissue sections of three gonadoblastomas in two patients with gonadal dysgenesis and 45,X/46,XY mosaicism. Statistical analysis of the data from the fluorescence in situ hybridization demonstrated that in all three gonadoblastomas, the proportion of nuclei with a Y chromosome signal was significantly higher in the tumor cells than in the nontumoral cells of the surrounding stroma (P<.001). These results suggest that Y chromosome material participates in gonadoblastoma tumorigenesis.

Hepatic explant specimens from 171 patients with cirrhosis were examined to determine the incidence of periodic acid-Schiff (PAS)-positive diastase-resistant globules (PDRGs) in end-stage hepatic disease and whether the globules bear a specific relationship to the alpha1-antitrypsin (A1AT) phenotype or to causes of hepatic disease other than A1AT deficiency. PAS-positive diastase-resistant globules were detected in 17 (10%) of the hepatic explant specimens, and the globules in all of these cases were strongly immunoreactive for A1AT. In the 17 patients with PDRGs, the cirrhosis was attributed preoperatively to A1AT deficiency (3 patients), ethanol abuse, viral hepatitis, or both (10 patients), cryptogenic cirrhosis (3 patients), and autoimmune hepatitis (1 patient). The A1AT isoelectric phenotypes classified according to the protease inhibitor (Pi) nomenclature for 16 of these patients were as follows: Pi ZZ (3 patients), Pi SS (1 patient), Pi MZ (8 patients), and Pi MM (4 patients). Because PDRGs were seen in a variety of A1AT phenotypes, serum electrophoretic analysis, not histologic examination, is required for the correct diagnosis of an A1AT abnormality. Furthermore, although PDRGs were seen in a variety of hepatic diseases, the majority of patients with globules had an undetected A1AT abnormality. Accordingly, on identification of hepatocytic PDRGs, the clinician should be alerted to the possibility of an unsuspected A1AT abnormality even in the presence of other causes of hepatic disease.

Using the polymerase chain reaction (PCR), it has been recently reported that the Epstein-Barr virus (EBV) is present in the majority of Schneiderian sinonasal papillomas (SNP) of the inverted type and may play a role in the pathogenesis of these lesions. The reported prevalence rates of human papillomavirus (HPV) in different types of SNP is also controversial and in need of clarification. Twenty-eight SNP from 27 patients were histologically classified and evaluated for evidence of EBV using PCR and 2 different sensitive and specific in situ hybridization (ISH) procedures for EBER1. Similarly, two methods of ISH were also used for the detection of HPV, using biotinylated DNA probes sensitive for 14 different HPV types as well as more sensitive and specific radioactive RNA probes for HPV types 6, 11, and 16. Polymerase chain reaction was successful in 19 papillomas, including 12 of 19 inverted SNP, 1 of 1 inverted SNP with squamous cell carcinoma, 4 of 5 fungiform SNP, and 2 of 3 oncocytic lesions. Southern blot hybridization of PCR products showed the presence of EBV DNA in two lesions, including one inverted SNP and the single inverted SNP with squamous cell carcinoma. By both DNA- and RNA-mRNA ISH, positivity for EBER was detected in rare stomal lymphocytes but not the overlying epithelium in the inverted SNP with SCC. The remaining cases, including the other inverted SNP positive for EBV by PCR, were completely negative by both ISH techniques. Human papillomavirus was detected by ISH in 1 of 19 (5%) inverted, 1 of 1 (100%) inverted with squamous cancer, 5 of 5 (100%) fungiform, and 0 of 3 (0%) oncocytic SNP. Three SNP contained HPV 6 (all fungiform), three SNP labeled for HPV 11 (two fungiform and the inverted SNP with squamous cancer), and one inverted SNP contained HPV 16. Of the five fungiform SNP, four showed foci of koilocytosis. The results indicate that EBV is not present in sinonasal papillomas. The presence of EBV positive stromal lymphocytes in these lesions may account for a proportion of PCR-positive cases. Oncocytic SNP are unassociated with HPV, whereas inverted SNP contain HPV in a minority of cases. In contrast, fungiform SNP are consistently associated with HPV types 6 and 11 and usually show histologic evidence of viral infection.

Epstein-Barr virus (EBV) has been implicated in the pathogenesis of a variety of lymphoproliferative disorders and several epithelial neoplasms, including undifferentiated nasopharyngeal carcinoma (UNPC; lymphoepithelioma). Lymphoepithelioma-like carcinomas (LEC) are tumors with morphologic features identical to UNPC that occur outside the nasopharynx. To determine whether EBV is associated with LEC, the authors conducted a comprehensive literature review of all pathologically documented LEC reported to date in the English literature. In summary, EBV is associated consistently with LEC from only four anatomic sites: stomach, salivary gland, lung, and thymus. Racial and/or geographic factors influence the association of EBV with LEC in some of these organs. Specifically, the association of EBV with LEC of the salivary gland and lung is restricted to Asian patients, whereas the association of EBV with gastric and thymic LEC is independent of race. The presence or absence of EBV in LEC does not appear to be prognotically important in those cases studies to date.

The interobserver reproducibility of the Nottingham modification of the Bloom and Richardson histologic grading scheme for invasive breast carcinoma was tested. Six surgical pathologists from four institutions independently evaluated histologic grade and each of its three components for 75 infiltrating ductal carcinomas. The number of slides per case ranged from one to nine (median 3). Pairwise kappa values for agreement ranged from moderate to substantial (0.43-0.74) for histologic grade. Generalized kappa values indicated substantial agreement for tubule formation (0.64), moderate agreement for mitotic count (0.52), and near moderate agreement for nuclear pleomorphism (0.40). Normalizing the mitotic counts per mm2 showed only slight improvement in agreement over the published range of mitotic counts for three different field areas. The results suggest that steps to discriminate between categories for nuclear pleomorphism would likely be of benefit for improving the interobserver reproducibility of histologic grade. Nevertheless, the Nottingham modification of the Bloom and Richardson grading system is recommended as a suitable scheme for evaluating invasive breast carcinomas in the routine clinical setting.

The existence of angiosarcoma of the thyroid gland and its relation to angiomatoid carcinoma have been debated. The authors reviewed eight angiomatoid thyroid neoplasms. Controls consisted of six sarcomatoid thyroid carcinomas without angiomatoid features and an angiosarcoma metastatic to the thyroid gland. All eight angiomatoid neoplasms consisted of epithelioid cells with prominent eosinophilic cytoplasm lining vascularlike spaces. All eight expressed vimentin. Four tumors were predominantly angiosarcomalike neoplasms, based on staining for factor VIII-related antigen (three of four), CD31 (four of four), CD34 (one of four), and Ulex europaeus I lectin (four of four); they lacked epithelial markers other than cytokeratin (two of four). Four tumors were designated as angiomatoid carcinomas, based on staining for multiple epithelial markers: cytokeratin (four of four), epithelial membrane antigen (three of four), thyroglobulin (three of four). Three angiomatoid carcinomas also expressed or labeled with one or more vascular markers: CD34 (one of four), CD31 (two of four), Ulex europaeus I lectin (one of four), factor VIII-related antigen (one of four). The metastatic angiosarcoma to the thyroid gland labeled for factor VIII-related antigen, vimentin, CD31, and with Ulex europaeus I lectin. It did not express CD34. The six sarcomatoid carcinomas without angiomatoid features stained for cytokeratin (four of six), epithelial membrane antigen (one of six), and vimentin (six of six). None labeled for thyroglobulin, factor VIII-related antigen, CD31, CD34, or with Ulex europaeus I lectin. Angiomatoid carcinomas of the thyroid gland exhibit both epithelial and endothelial features. "Angiosarcoma" may represent the extreme in this spectrum of endothelial differentiation. All tumors behaved in a similar clinical fashion characterized by persistent local disease, widespread metastases and poor prognosis.

Twenty-one lobular capillary hemangiomas (LCH), including lesions from six pregnant patients, were examined by immunohistochemical analysis. Antibodies to estrogen and progesterone receptor proteins were used to determine whether these steroid hormones play a direct role in LCH development and growth. All 21 LCHs were negative for both receptor proteins. Contrary to the association of LCH with pregnancy and oral contraceptive use, the absence of these steroid receptors strongly suggests that estrogen or progesterone are not directly involved in the formation of these lesions. All 21 LCHs were stained with Ulex europaeus lectin and with a panel of antibodies directed against cytokeratin, vimentin, Factor VIII, collagen Type IV, and muscle-specific actin. Endothelial cells in LCH, both in cellular proliferations with poorly formed lumens and in well-formed capillaries, were labeled by Factor VIII, Ulex europaeus lectin, and vimentin. A population of concentrically arranged, perivascular spindle-shaped cells was highlighted by positive staining for muscle-specific actin, collagen Type IV, and vimentin. The spindled cells were associated with both well-developed and immature vessels in all lesions. The appearance, immunophenotype, and location of these cells is consistent with a pericytic origin. Although the intimate association of both endothelial cells and pericytes suggests a reactive, as opposed to neoplastic, origin, other benign vascular tumors traditionally considered neoplastic have a similar bicellular composition. Accordingly, the findings neither support nor refute a neoplastic origin for LCH.

Localized herpetic lymphadenitis is an extremely uncommon complication of herpes simplex virus (HSV) infection. The authors report two cases of localized herpetic lymphadenitis, both showing well-circumscribed areas of necrosis containing cells with diagnostic intranuclear inclusions. Electron microscopic studies in both cases revealed characteristic viral particles, and in situ hybridization studies using a herpes simplex genomic probe demonstrated HSV DNA in both specimens. Immunohistochemical studies demonstrated that the cells containing the inclusions were stromal, not lymphoid, cells. Combining the current two cases with the six well-documented cases previously reported in the literature, seven of the eight cases of HSV lymphadenitis have developed in inguinal lymph nodes, with four occurring in patients with previously or subsequently diagnosed hematopoietic malignancies, including both patients in the current series.

The clinicopathologic, immunohistochemical, and flow cytometric characteristics of 34 cases of mammary carcinoma with metaplasia were compared with those of 20 cases of pure sarcoma of the breast. All 20 of the latter tumors showed the pattern of malignant fibrous histiocytoma. There were 20 cases of carcinoma with mesenchymal metaplasia, 7 cases of carcinoma with mixed epithelial (squamous) and mesenchymal metaplasia, and 7 cases of carcinoma with epithelial metaplasia (four mixed ductal/squamous and three pure squamous cell carcinomas). No patient with pure sarcoma had lymph node metastases develop; all nodal metastases were found in patients who had carcinoma with metaplasia, although in one case the carcinomatous component was seen only within a lymph node metastasis. Epithelial antigens were found not only within the epithelial elements of all cases of carcinoma, but also within the apparent mesenchymal elements of 44% of the carcinomas showing divergent differentiation. Flow cytometric analysis of eight cases of carcinoma with mesenchymal metaplasia showed aneuploidy/tetraploidy in six neoplasms. For patient management purposes, the distinction of pure sarcoma from carcinoma with metaplasia is important, but additional subclassification of carcinoma with metaplasia is of greater biologic than clinical interest.

Five previously unreported cases of adrenal pseudocysts are described that demonstrate a wider range of histologic appearances than has been previously recognized in these lesions. One pseudocyst removed from an asymptomatic 59-year-old female contained intracystic nests of cytologically malignant cells of unknown origin. Workup revealed a left breast mass, which on biopsy showed an infiltrating ductal carcinoma with neoplastic cells that were cytologically similar to those found within the cyst contents. Four other pseudocysts are described with variable numbers of intracystic vascular structures and benign adrenal cortical cells. In addition, intracystic mature adipose tissue was observed in all four cases, with myelolipomatous metaplasia found in one. Awareness of the wide histologic variability of these lesions should improve diagnostic accuracy and allow distinction from adrenocortical neoplasia and myelolipoma.