Necrosis and hemorrhage are uncommon. Microscopically, seminomas consist of sheets of large clear cells, divided by delicate vascular septae with lymphocytic infiltration. Granulomatous areas and multinucleated giant cells can occur. Spermatocytic seminomas are uncommon and usually affect men over age 60. Grossly, they are larger then classic seminomas.
Embryonal carcinomas tend to show gross necrosis and hemorrhage.
They usually occur in the third decade. Microscopically, embryonal carcinomas are large, pleomorphic cells, most commonly glandular but also tubular, alveolar, papillary and solid patterns. The neoplastic cells contain basophilic cytoplasm with large pleomorphic nuclei and solitary prominent nucleoli. Cell borders are usually indistinct. Mitoses are common.