Alveolar Rhabdomyosarcoma of the Paranasal Cavity in an Adult Woman

Abstract

Alveolar rhabdomyosarcoma (RMS) is extremely rare in adults older than 45 years and may be very difficult to distinguish from other primitive round cell neoplasms without immunohistochemistry and/or genetic studies. In adults, the differential diagnosis of small round cell tumors of the head and neck region includes small cell carcinoma, lymphomas and neuroepithelial tumors, such as esthesioneuroblastoma and, as last choice, rhabdomyosarcoma. Initial immunoprofiling may not include myogenic markers. Moreover, aberrant expression of epithelial and neuroendocrine markers in alveolar RMS may be a potentially serious diagnostic pitfall. In this report, we describe the clinico-pathological features of a case of paranasal alveolar RMS in a 61-year-old woman with no previous history of neoplasia and discuss the differential diagnosis of small round cell tumor in the nasal/paranasal cavity.