Background. Primitive neuroectodermal tissue in teratomas of testis has been reported in the literature. A mixed germ cell tumor of testis with a prominent neuroblastoma component dictating the clinical behavior was found to be unique.
Methods. Tissue sections were stained with hematoxylin and eosin, and immunohistochemical, ultrastructural, cytogenetic, and flow cytometric analyses were performed on the primitive neuroectodermal component of the testicular mass. Follow-up results at 2.5 years are included,
Results. The microscopic findings on hematoxylin and eosin slides showed cells composing the majority of the neoplasm to have features of neuroblastoma. The immunohistochemical stains showed positivity for neuronspecific enolase in the cells comprising the neuroblastoma, and transmission electron microscopic study corroborated these findings by demonstrating microtubules and rare membrane-limited, dense-core granules in the cytoplasm. Flow cytometry showed a hypertetraploid population with a large aneuploid DNA content. Cytogenetics revealed a hypertriploid modal number of 74 chromosomes. The clinical features were dictated by the neuroblastoma component in a fashion similar to that of adult neuroblastomas and responded to the chemotherapeutic regimen designed for treating neuroblastoma.
Conclusions. The neuroblastoma component proved to be more aggressive than the other elements of this neoplasm. This finding suggests that mixed germ cell tumors From the