Ovarian-type Tumors (Mullerian Tumors) of the Testis: Clinicopathologic Findings with Recent Advances

Ovarian-type epithelial tumors rarely occur in the human testis and paratesticular region. Histologically, these tumors closely resemble their ovarian counterparts and are therefore classified similarly to ovarian epithelial tumors. Most reported ovarian-type tumor cases are serous tumors, but the full spectrum of ovarian neoplasms has been described, including mucinous, endometrioid, clear cell, and Brenner tumors. In this review, we describe the clinical, morphologic, and immunohistochemical features of Mullerian-type epithelial tumors seen in the testis, with an emphasis on comparison with ovarian tumors. We also discuss theories of pathogenesis, considerations in the differential diagnosis, and recent advances in molecular characterization and therapeutic modalities.