Ovarian sertoli-leydig cell tumors with pseudoendometrioid tubules (pseudoendometrioid sertoli-leydig cell tumors).

The propensity for ovarian endometrioid adenocarcinomas to morphologically mimic Sertoli, Sertoli-Leydig, and granulosa cell tumors, is well known. The converse situation, mimicry of an endometrioid neoplasm by a sex cord-stromal tumor, has not been emphasized. In this report, we describe 9 ovarian Sertoli-Leydig cell tumors (5 well differentiated, 4 of intermediate differentiation) with areas containing hollow, sometimes dilated, tubules which resemble endometrioid glands; we refer to these as pseudoendometrioid tubules. The age of the patients ranged from 14 to 57. The tumors, all of which were unilateral except for one, ranged from 3.5 to 19 cm and were variously described as tan, pale, yellow, or gold. The proportion of the tumor made up of pseudoendometrioid tubules ranged from 10% to >90%. When widespread, their presence sometimes resulted in consideration of a borderline endometrioid adenofibroma or a well-differentiated endometrioid adenocarcinoma. However, all the neoplasms contained typical Sertoli tubules and one or more of the characteristic patterns of Sertoli-Leydig cell tumors as well as Leydig cells, although the latter cells were inconspicuous in some cases. Immunohistochemistry, performed in 4 cases, showed that the pseudoendometrioid tubules, as well as the more typical Sertoli cell elements, were either positive for alpha inhibin (3 of 4 cases) or calretinin (3 of 4 cases) or both, although sometimes focally so. These elements were negative with epithelial membrane antigen and cytokeratin 7. In all 4 cases, the pseudoendometrioid tubules were positive with the broad spectrum cytokeratin AE1/3. This report illustrates the potential for ovarian Sertoli-Leydig cell tumors to contain tubules with a pseudoendometrioid appearance which mimic a borderline or malignant endometrioid neoplasm. The presence of more typical Sertoli cell elements and Leydig cells, an absence of squamous elements, endometriosis or associated adenofibroma, and the characteristic immunophenotype assist in diagnosis.