Low-grade sarcoma in classical seminoma - the first case reported.

A 30-year-old male with no previous history of neoplastic disease presented with a 5 cm large testicular tumor. Routine histopathological examination and immunohistochemical investigation showed a classical seminoma with a contiguous 8 mm large nodule. The nodule was separated from the tunica albuginea by tubuli seminiferi showing intratesticular germ cell neoplasi not otherwise specified (NOS). The nodule was composed of spindle cells with low-grade nuclear atypia, nuclear and cytoplasmic S100 protein immunoreactivity in 15% of the cells and a proliferative activity of up to 20%. No other germ cell tumor components were found. To the best of our knowledge, we herein present the first tumor of a pure classical seminoma with an associated low-grade sarcomatous component.