Pleural effusion cytology of embryonal rhabdomyosarcoma

This case report concerns an embryonal rhabdomyosarcoma of the testis in a 31-yr-old white male patient who underwent radical left orchiectomy, followed by combined irradiation and chemotherapy, and who 2 yr later presented with dyspnea at rest, nonproductive cough, and lower back pain for 1 wk. Chest radiographs demonstrated a bilateral pleural effusion and diffuse infiltrating lesion of the pleurae, mimicking a mesothelioma. The pleural fluid displayed noncohesive, malignant, small, round cells about 2-5 times larger than mature lymphocytes. They had large, darkly stained, pleomorphic nuclei and bubbly cytoplasm with poorly defined borders. The diagnosis of embryonal rhabdomyosarcoma was supported by a positive myosin immunostaining and ultrastructural findings of intracytoplasmic actin and myosin-type microfilaments. Our case is also notable in that the tumor was a pure rhabdomyosarcoma involving a testicular origin, and the patient is the oldest reported in the literature.