Adult rhabdomyoma in the parapharyngeal space: report of 2 cases and review of the literature.

Rhabdomyomas are rare benign mesenchymal tumors with skeletal muscle differentiation. They are less commonly encountered than are their malignant counterparts, rhabdomyosarcomas. Rhabdomyomas fall into 2 general categories: cardiac and extracardiac types. Extracardiac rhabdomyomas are among the rarest tumors in humans and can be subclassified as fetal, juvenile, and adult types depending on the individual tumor's degree of differentiation by light microscopy. Adult extracardiac rhabdomyoma has a strong predilection for occurrence in the head and neck, mainly in the area of larynx and pharynx. In this article, 2 cases of parapharyngeal rhabdomyoma are reported together with a review of the world literature.