46,XX gonadal dysgenesis, gonadoblastoma, dysgerminoma, and tumor markers

JRT Mendesa, R Delcelob, SAP Pontea, V Freitasc, ITN Verreschi a.

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

Gonadoblastoma, a mixed germ cell-sex-cord-stromal tumor, is a common tumor in patients with streak gonads under Y-chromosome material (Y-chm) influence. It is composed of germ cells resembling seminoma cells, and immature Sertoli cells, with peripheral Leydig-like-cells. Gonadoblastoma is considered an in situ germ cell tumor since it gives rise to a malignant germ cell tumor, Dysgerminoma. Exceptionally both tumors occur in dysgenetic gonads without Y-chm. Others factors like WT1 (Wilms Tu gene), and hormones, such as inhibin (Ih) and mullerian inhibiting substance (MIS), might be implicated in tumorigenesis. A 20-years-old woman 46,XX without Y-chm by PCR is described with primary amenorrhea, normal height, rudimentary uterus and streak gonads, in which histopathological analysis disclosed a focal gonadoblastoma with dysgerminoma associated to hillus cell hyperplasia in the left gonad. Testosterone production, WT1, Ih, p53, and MIS expression were searched by immunohistochemical methods. The smaller cells of the gonadoblastoma were positive for Ih, all cellular components were positive for MIS, less than 20% of cells were positive for WT-1 and, the cells were negative for T and p53. A few cells of dysgerminoma were positive for WT1, and negative for all others markers. Results were different from that observed in literature. Malignancy arising in the gonadal tissue is always of concern in patients with gonadoblastoma. In the present case dysgerminoma developed in a 46,XX milieu, in the absence of Y-chm pointing to the possibility of other markers alone or associated to the high levels of FSH.

KEY WORDS: Gonadal Dysgenesis, Gonadoblastoma, Dysgerminoma, Tumor Markers.

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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.