Sclerosing Sertoli cell tumor without expression of typical sex cord stromal tumor markers: case report and literature review.

Sertoli cell tumor is a potential histologic mimic of other tumors, such as seminoma due to similar histology and overlapping clinical presentation. Sclerosing Sertoli cell tumor is a rare sex cord stromal tumor variant, with 16 cases reported in the English literature. We present an unusual case of sclerosing Sertoli cell tumor in a 33-year-old Caucasian male, which was negative or weakly reactive using immunohistochemical markers typically positive in Sertoli cell tumors. The tumor was positive for cytokeratin AE1/AE3, CAM 5.2, vimentin, CD56, CK8, synaptophysin and S100, and negative for inhibin, calretinin, WT1, CD99, CD117, CK5/6, CK7, chromogranin A, placental alkaline phosphatase, neuron specific enolase, D2-40, smooth muscle actin, Melan-A, epithelial membrane antigen and carbonic anhydrase IX. This is the second reported case of a Sertoli cell tumor with reactivity limited to neuroendocrine markers and the first such case of the sclerosing variant. A literature review of sclerosing Sertoli cell tumor, including English and non-English literature, is described. Our case highlights that expected immunohistochemical markers may be negative, and awareness of antigenically unreactive tumors is needed to avoid confusion between Sertoli cell tumor and other entities.