(1002) A Rare Case of Pediatric Sinonasal Myxoma With Extraconal Intraorbital Extension

Introduction: Sinonasal myxoma is a rare, benign tumor arising from mesenchymal tissue. Sinonasal myxomas typically present with nonspecific symptoms of nasal obstruction, facial pain, epistaxis, and headache. Due to its rarity, diagnosis requires a high clinical index of suspicion.

Methods: We report the case of an 18-month-old male with sinonasal myxoma presenting to our institution. The study was IRB exempt and all data were collected from the Electronic Medical Record.

Results: An 18-month-old male presented with 3-month history of right facial swelling of the infraorbital region initially treated as otitis media. Physical exam reveled right infraorbital swelling without erythema or induration. Magnetic resonance imaging (MRI) revealed a maxillary sinus mass with extraconal intraorbital extension. Biopsy confirmed low-grade myxoid spindle cell neoplasm. Definitive treatment involved complete excision of the mass via Weber-Fergusson incision and maxillectomy, with reconstruction with rib graft and right adipofascial ALT free flap. The patient recovered from the surgery without postoperative complications. At 4 months postoperatively, he had an abscess at the maxillectomy site within the free flap tissue which was treated with needle aspiration and antibiotic therapy with resolution confirmed via imaging and clinical exam. At 8-month follow-up, he had an excellent cosmetic result, no functional deficits including no issues with his dentition or vision, and MRI showed no evidence of recurrent tumor.

Conclusions: Sinonasal myxomas are very rare benign neoplasms of the maxillary sinus, with an average age of presentation of 15.4 months old. Here, we present the case of an 18-month-old male with infraorbital extension of sinonasal myxoma, requiring complete excision and reconstruction using an ALT free flap and rib graft reconstruction of orbital rim. Successful treatment in this case required a multi-disciplinary approach resulting in excellent tumor control and functional/cosmetic outcome. Sinonasal myxoma should remain on the differential for a child presenting with a sinonasal based facial mass.