Alveolar Rhabdomyosarcoma of the Lip in an Adult with Clear Cell Features

Abstract

Rhabdomyosarcoma, which occurs in the head and neck, genitourinary tract and deep soft tissue of the extremities and typically presents in childhood or adolescence, is a malignant mesenchymal tumor showing differentiation of skeletal muscle. 1,2 Less than 3% of rhabdomyosarcoma cases present in adults. Although rhabdomyosarcoma frequently occurs in the head and neck region, involvement of the lips is very rare; only 8 cases have been reported in the English literature. 3-10 Conventionally, rhabdomyosarcoma is categorized into embryonal, alveolar and pleomorphic subtypes. 11 We report a case of alveolar rhabdomyosarcoma with clear cell features presenting as a perioral subcutaneous nodule on the upper lip of a 58-year-old woman. A review of the literature and possible differential diagnoses are described.