Embryonal rhabdomyosarcoma of the paranasal sinuses: a case report and review of literature.

Embryonal rhabdomyosarcoma (ERMS) is a rare malignancy with a poor outcome. In this article, we describe a case of ERMS in the paranasal sinuses from a 60-year-old male patient. ERMS derived from the paranasal sinuses is extremely rare. The diagnosis of ERMS must be based on histological findings and immunohistochemical findings. In this case, microscopic observation showed tumor cells were arranged in flocked sheets, cord-like and acinar-like by hyperplastic fibrous tissue. And ERMS tissues were immunopositive for myogenin, desmin, MSA, CD56, vimentin, CD99, Syn and Ki-67 (40%+), and immunonegative for CK, EMA, LCA, GFAP, NSE, S-100, HMB-45 and Melan-A. Here, the patient was treated with multimodal therapy including endoscopic surgery, chemotherapy and radiation, but the patient's postoperative recovery is not too smooth.