Endoscopic Resection of Solitary Fibrous Tumor of the Anterior Skull Base

Sinonasal glomangiopericytomas, formerly called sinonasal hemangiopericytomas, are rare, vascular tumors with predilection for the sinonasal tract. These soft tissue tumors with hemangiopericytoma-like growth patterns are now divided into three categories: (1) solitary fibrous tumors, (2) lesions showing evidence of myoid/pericytic differentiation, and (3) neoplasms that occasionally display hemangiopericytoma-like features (e.g., synovial sarcoma).

Solitary fibrous tumors are tumors of CD34-positive fibroblasts that often show a prominent hemangiopericytoma-like vascular pattern. They are very uncommon in the sinonasal tract, comprising less than 0.1% of all neoplasms. These tumors can be easily misdiagnosed as sinonasal glomangiopericytomas. Here we describe a patient with sinonasal solitary fibrous tumor eroding and extending into the anterior cranial fossa. The patient had previously undergone transnasal endoscopic resection of a tumor described as a glomangiopericytoma, reportedly confined to the middle turbinate. Ten months later, he presented with an intracranial hemorrhage, and MRI demonstrated a mass eroding into the anterior cranial fossa from the nasal cavity with overlying hemorrhage into the left frontal lobe. The patient was treated with a purely endoscopic endonasal anterior craniofacial resection, including the intracranial portion. Complete resection was obtained with negative margins. The skull base was reconstructed using dural substitutes and nasal septal flaps. No postoperative complications were observed. The patient was discharged at postoperative on day 3. Per our knowledge, this is the first reported skull base solitary fibrous tumor treated with a purely endoscopic approach.