Pure alveolar rhabdomyosarcoma of the uterine corpus

Herein is presented a very rare case of alveolar rhabdomyosarcoma in the uterine corpus of a 72-year-old woman. The wall of the uterine corpus was replaced by multiple whitish-yellow, friable nodules, measuring up to 6 cm. Microscopically, the tumor was predominantly composed of round to polygonal cells arranged in an alveolar, papillary or nest pattern intermingled with multinuclear giant cells with abundant eosinophilic cytoplasm. Extensive sampling failed to show epithelial elements. Immunohistochemically, the tumor was positive for striated muscle markers such as myoglobin, myoD1 and myogenin. Metastatic lesions were found in the retroperitoneum and pelvic lymph nodes. The patient was treated by postoperative chemotherapy, but she died of systemic metastases 12 months after surgery.