Unclassifiable Malignant Extraovarian Sex Cord-Stromal Tumors: Report of 3 Cases and Review of Extraovarian Sex Cord-Stromal Tumors.

We report 3 cases of primary extraovarian unclassifiable malignant sex cord-stromal tumors. In all cases, the tumors involved the pelvis, peritoneum, and/or omentum and the morphologic features were essentially those of a poorly differentiated malignant neoplasm. A diagnosis of sex cord-stromal tumor was made on the basis of expression of several markers of ovarian sex cord-stromal tumors and exclusion of other neoplasms. In 1 case, an elevated serum testosterone was present at tumor progression. In reporting these cases, we draw attention to the problems in establishing a diagnosis that can be attributed to the extreme rarity of sex cord-stromal tumors in an extraovarian location and the rarity of unclassifiable malignant sex cord-stromal tumors in general, resulting in pathologists not considering this diagnosis. We review sex cord-stromal tumors occurring in an extraovarian location.