(1231) Familial Adenomatous Polyposis-Associated Juvenile Nasopharyngeal Angiofibroma Managed with a Novel Embolic Agent

Introduction: Juvenile nasopharyngeal angiofibroma (JNA) is a benign but highly vascular tumor that primarily affects male adolescents and can present significant surgical challenges due to its locally invasive nature. JNA associated with familial adenomatous polyposis (FAP) has been described in the literature, though the association has not been well established.

Methods: This case report describes a 20-year-old male with a history of FAP and prior left pterygoid osteoma extraction who presented with nasal congestion and recurrent epistaxis. FAP had been confirmed six months prior through genetic testing identifying a pathogenic APC variant in the setting of affected family members. Diagnostic imaging, preoperative embolization, and endoscopic surgical resection were performed. Preoperative embolization included direct embolization using a novel, non-confirming embolic agent combined with 25% n-butyl cyanoacrylate (n-BCA) glue, followed by transarterial embolization of a distal internal maxillary artery branch. Endoscopic endonasal debulking and resection were completed 24 hours later.

Results: CT demonstrated a left-sided, vascular nasopharyngeal mass with extension to the medial pterygoid and sphenoid bases, raising suspicion for a UPMC Grade 1 JNA. Pathology of the mass confirmed a 4 cm nasopharyngeal angiofibroma positive for beta-catenin and androgen receptors.

Conclusions: This case is important because FAP-associated JNA is rare, and recognition of this relationship can guide earlier diagnosis and highlight the role of APC-related pathways in tumor development. The successful use of a novel embolic agent also demonstrates its potential value in managing highly vascular skull base tumors.