Unusual leptomeningeal dissemination in a child with extracranial metastatic alveolar rhabdomyosarcoma.

The authors describe a 6-year-old boy diagnosed with alveolar rhabdomyosarcoma located in the thigh, with distal metastases to lungs, bones, and bone marrow. A very good partial response to first-line chemotherapy was obtained, but the child developed fatal leptomeningeal dissemination immediately after complete resection of the primary tumor. This case demonstrates the rapidity with which leptomeningeal spread of extracranial metastatic alveolar rhabdomyosarcoma can occur and underscores the importance of diagnostic lumbar puncture and brain radiological investigations at diagnosis, even when the tumors are not in the parameningeal location.