An Insidious Source of Chronic Sinusitis and Recurrent Epistaxis: A Rare Case of Skull Base Glomangiopericytoma.

Glomangiopericytoma (GLC) is a rare malignant tumor of the sinonasal cavity that can lead to a variety of non-specific symptoms and consequently cause inaccurate diagnosis and delayed management. This can ultimately cause irreversible damage to the quality of life and result in a poor prognosis. We present the case of a 55-year-old male patient who suffered from the symptoms of chronic rhinosinusitis, anosmia, and multiple episodes of epistaxis with an endoscopic finding of a right-sided polyp-like mass within the sinonasal cavity. Further imaging studies revealed a mass originating from the skull base and a right-sided sphenoid sinus mucocele. Endoscopic endonasal resection and histopathological analysis confirmed a rare skull base GLC. The objective of this case report is to emphasize the diagnostic challenge of GLC due to its rare occurrence and bring awareness to its insidious and malignant nature that hides behind long-term sinonasal symptoms, mimicking chronic rhinosinusitis.