Surgical and Clinical Outcomes of Intracranial, Craniofacial, and Spinal Solitary Fibrous Tumors: A 15-year Institutional Case Series

Introduction: Solitary fibrous tumors (SFTs), formerly hemangiopericytomas, are rare, aggressive mesenchymal malignancies molecularly characterized by a NAB2-STAT6 gene fusion and associated with elevated recurrence rates and the potential for distal metastasis. We report our institutional experience managing intracranial, craniofacial, and spinal SFTs while analyzing trends in long-term follow-up data to help optimize treatment of these rare tumors.

Methods: A retrospective chart review was conducted from 2009-2023, which identified 24 histopathologically confirmed intracranial, craniofacial, and spinal SFT cases.

Results: Twenty-four SFT cases were identified with a mean age of 54.1 years and an equal gender distribution. Tumors were primarily intracranial (n=11, 45.8%), followed by craniofacial (n=7, 29.2%), and spinal (n=6, 25%). Initial presenting symptoms most frequently involved focal neurological deficits (n=15, 62.5%) and headaches (n=7, 29.2%). Mean overall follow-up was 42.5 months. Seven patients (29.2%) already had a known history of SFT on presentation. Surgical resection was the primary treatment in 22 patients (91.6%), with gross total resection (GTR) achieved in 15 (62.5%) based on postoperative imaging. Preoperative tumor embolization was performed in 7 cases. Pathology revealed WHO Grade 2 tumors in 13 patients (54.2%) and WHO Grade 3 tumors in 11 patients (45.8%). Postoperative management varied across the cohort; the majority of patients were observed only (n=15, 62.5%), 8 patients (33.3%) received radiation therapy, usually intensity-modulated radiation therapy, and 3 patients (12.5%) received systemic chemotherapy. There were 4 recurrences and 4 new extracranial metastases observed during follow-up. Mean progression-free survival was 57 months, with GTR significantly prolonging progression free survival.

Conclusion : Our institutional experience provides insights into the recurrence rate, metastatic potential, and overall clinical outcomes of intracranial, craniofacial, and spinal SFTs. There was notably improved progression-free survival after GTR across cases. Pooled or multi-institutional cohort analysis remains necessary to elucidate the impact of adjuvant treatments on these rare tumors.