Orbital Rhabdomyosarcoma Masquerading as a Dermoid Cyst: A Case Report and Review of the Literature.

The purpose of this report is to present a case of orbital rhabdomyosarcoma (RMS) masquerading as a dermoid cyst. A six-year-old boy with an unremarkable medical history presented in the outpatient department with a palpable mass in the superonasal region of the right orbit, which had rapidly grown in the past month. The most likely diagnosis was dermoid cyst and the patient was scheduled for surgical excision. A high index of suspicion was raised intraoperatively based on the appearance of the lesion due to the presence of a feeder vessel. The histopathology examination identified alveolar RMS. The patient was referred to a pediatric oncology department and commenced intravenous chemotherapy. RMS may masquerade as various conditions, including dermoid cysts and chalazion. A high index of suspicion should be raised in cases with rapidly growing lesions.