This case report concerns an embryonal rhabdomyosarcoma of the testis
lit a 31-yr-old white male patient who underwent radical left orchiect
omy, followed by combined irradiation and chemotherapy and who 2 yr la
ter presented with dyspnea at rest, nonproductive cough, and lower bac
k pain for 1 wk. Chest radiographs demonstrated a bilateral pleural ef
fusion and diffuse infiltrating lesion of the pleurae, mimicking a mes
othelioma. The pleural fluid displayed noncohesive, malignant, small,
round cells about 2-5 times larger than mature lymphocyes. They had la
rge, darkly staining, pleomorphic nuclei and bubbly cytoplasm with poo
rly defined borders. The diagnosis of embryonal rhabdomyosarcoma was s
upported by a positive myosin immunostaining and ultrastructural findi
ngs of intracytoplasmic actin and myosin-type microfilaments. Our case
is also notable in that the tumor. was a pure rhabdomyosarcoma involv
ing a testicular origin, and the patient is the oldest reported in the
literature. (C) 1997 Wiley-Liss, Inc.