Pathology

• SPECIMEN: LEFT TESTIS CLINICAL INFORMATION: None provided. GROSS DESCRIPTION: The specimen is received in 1 container(s). The specimen is received fresh from the Operating Room for frozen section diagnosis, labelled with the patient's name and "L TESTIS", and consists of a testis measuring 10.2 x 5.5 x 2.8 cm. The testis measures 5.5 x 5.2 x 3.1 cm. The spermatic cord measures 5.2 x 0.8 x 0.4 cm. and is grossly unremarkable. On cut surface, the parenchyma is tan and soft. The epididymis is unremarkable. A poorly defined mass, 1.2 x 0.8 x 0.6 cm. in greatest dimension is located in the lower pole of the testis. The lesion appears to be confined within the capsule of the testis. An appendix testis, 1.2 x 0.8 x 0.5 cm. in greatest dimension is present on the superior surface of the testis. The entire margin is inked in black. COMMENTS: Sections of the main tumor mass show an invasive neoplasm composed of nests of moderately sized cells with abundant clear cytoplasm, and nuclei with a diffuse homogeneous chromatin pattern. Numerous lymphocytes are admixed with the tumor. These appearances are consistent with a seminoma. Away from the main invasive tumor mass, numerous seminiferous tubules contain intratubular neoplasm. Tumor also extends in a pagetoid fashion along the rete testis. Here, scattered lymphocytes are admixed with the tumor cells which appear somewhat more anaplastic than in the main invasive tumor component. In addition, a single focus of tumor with a well circumscribed configuration is seen (A6) which has a papillary configuration. The tumor cells here are larger and contain somewhat basophilic cytoplasm and have large nuclei with marginated chromatin and prominent nucleoli. These tumor cells appear, highly pleomorphic in comparison to the seminoma and their configuration is consistent with embryonal carcinoma. Immunostains for cytokeratin are negative within the seminoma (both invasive and intratubular components), and in striking contrast, are positive within the embryonal carcinoma component. Stains for placental alkaline phosphatase are positive within the seminoma, and much reduced staining is seen within the embryonal carcinoma. Staining for epithelial membrane antigen is faintly positive, and for alpha-feto-protein is focally strongly positive. Minimal positivity for vimentin antigen is seen. These immunostains support the interpretation of a mixed germ cell tumor. Sections of the grossly normal testis also show intratubular seminoma. Other seminferous tubules show a reduction in spermatogenesis some containing predominantly Sertoli cells. Peritubular fibrosis is seen. These appearances are suggestive of mal- descended or late testis descent.