Primary cutaneous alveolar rhabdomyosarcoma, an uncommon entity

Although secondary rhabdomyosarcoma (RMS) of the skin is not uncommon, the primary type is rare. RMS arising on subcutaneous tissue in an adult is sorely uncommon. It usually affects the skin of the face. Among the four histologic subtypes, the alveolar variant is the least frequently presented variant. Here, the authors introduce a patient with primary cutaneous alveolar RMS of the scalp. The tumor manifested as an immense plaque-like lesion confined to the scalp. The diagnosis was made by histological and immunohistochemical features of the biopsied specimen. Immunohistochemistry stains revealed that the tumor cells were positive for Desmin and negative for HMB45 and CD34. Surgery combined with adjuvant chemotherapy seems to be the best treatment. If complete resection of the lesion is not possible, radiotherapy is recommended. This case demonstrates that primary cutaneous RMS should be considered in the assessment of peculiar malignant tumors of the skin, and proper ancillary studies will be helpful.