Immunohistochemical expression of testosterone, mullerian-inhibiting substance, p53, inhibin, and WT-1 in the cells of gonadoblastoma, dysgerminoma, and seminoma.

JRT Mendes a, R Delcelo b, ITN Verreschi a.

a Endocrine Unit, Department of Medicine, b Department of Pathology, Universidade Federal de Sao Paulo UNIFESP-EPM, Brazil.

The present study apprise the possibility that factors controlling sex organ development might be implicated in tumorigenesis of gonadoblastomas, seminomas and dysgerminomas even in the absence of Y-chromosome (Y-chm) influence. Ten patients from the files of the Department of Pathology-UNIFESP and one from a private laboratory were selected through a survey of archival, formol-fixed, paraffin-embedded tissues where six gonadoblastomas, four seminomas, and five dysgerminomas were disclosed. Each tumor was immunohistochemically evaluated by peroxidase-antiperoxidase method for the detection of testosterone (T), p53, WT-1 (Wilms Tu gene), MIS (mullerian inhibiting substance), and Ih (inhibin), using specific antibodies. All tumors were negative for T; six gonadoblastomas and four dysgerminoma were positive and all seminomas were Ih negative; four gonadoblastomas, three dysgerminomas and two seminomas were p53 positive; four gonadoblastomas, all dysgerminomas and two seminomas were WT-1 positive; two gonadoblastomas, all dysgerminomas and one seminoma were MIS negative. Gonadoblastoma gives rise to a malignant germ cell tumor, dysgeminoma which is indistinguishable from the testicular seminoma. With few exceptions, gonadoblastomas have been found in patients with dysgenetic gonads and Y-chm. Dysgerminomas developed in individuals with a normal 46,XX or with a single 45,X cell line and no evidence of Y-chm. For this reason, all patients with or without Y-chm and dysgenetic gonad need a prophylatic gonadectomy. In the absence of Y-chm, others markers could be applied to determine if a patient will need prophylatic gonadectomy. Ih, a useful histologic marker for sex-cord stromal tumor, could be the choice.

KEY WORDS: Immunohistochemistry, gonadoblastoma, dysgerminoma, seminoma.

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Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Paris, France; February 9 - 12, 2002; in the section on Diagnostic Markers.