Adult embryonal rhabdomyosarcoma in the nasal cavity; a case report with a review of the literature.

Introduction: Rhabdomyosarcoma (RMS) is a primitive malignant soft tissue tumor arising from premature mesenchymal cells. The current study presents a rare case of embryonal rhabdomyosarcoma in the nasal cavity of an adult patient. Case presentation: An 18-year-old female presented with right nasal obstruction for five months. Examination showed a pale soft, painless mass in the right nasal cavity with attachment to the nasal septum at the osteocartilaginous junction. The patient was falsely suspected for bacterial infection, but later histological examination showed undifferentiated small round blue cell tumor with extensive necrosis. Immunohistochemistry confirmed the diagnosis of embryonal RMS. The patient was operated on for endoscopic sinus surgery to remove the mass with additional cleaning of surrounding sinuses. Discussion: Embryonal RMS is a rare type of malignant tumor that mostly affects the head and neck area in children while usually occur in the extremities of adults. Encountering an adult ERMS of the nasal chambers represents a small portion of head and neck cases that lack specific presentations. Conclusion: Adult embryonal RMS of the nasal cavity is exceedingly rare and presents a diagnostic and management challenge, with immunohistochemistry being the only definitive diagnostic method.