Alveolar rhabdomyosarcoma arising in the nasal cavity of a 3-year-old child.

A 3-year-old girl had a large exophytic mass protruding from the nares, of seven months' duration. Routine microscopic studies demonstrated a tumor composed of solid sheets of small cells, with scattered foci lining alveola-like spaces. Immunohistochemical studies demonstrated the presence of desmin and myoglobin, and the absence of prekeratin, neuron-specific enolase, and leukocyte common antigen. These observations are consistent with the diagnosis of alveolar rhabdomyosarcoma.