Massive Solitary Fibrous Tumor (SFT) of the Infratemporal and Pterygomaxillary Fossa Treated by Combined Endoscopic Approach

Abstract

Solitary fibrous tumors (SFTs) were first described as spindle-cell tumors originating from the pleura. Until recently, there was some debate with regards to the name and origin of these tumors and the distinctions with the term haemangiopericytomas (HPCs), a rare type of vascular tumor . Morphological, immunohistochemical and clinical features of HPCs were not specific for one entity. With the exception of myopericytoma, infantile myofibromatosis and HPC-like lesions of the sinonasal tract showing myoid differentiation, all other HPC-like lesions are best considered as subtypes of SFT. Due to their mesenchymal origin, we are now aware that SFTs may involve several extrapleural sites including soft tissues or meninges. When SFTs involve the skull base and show malignant histological characteristics, they can be an important challenge for the surgical team. We report a case of a 54-year-old man complaining of poor vision and facial pain that had worsened over the last year. Computed tomography and magnetic resonance imaging indicated a large mass, involving the right infratemporal and pterygomaxillary fossa. A biopsy proved positive for a solitary fibrous tumor with malignant features. Surgery was performed using a combined approach of frontotemporal craniotomy and nasal endoscopy. The subtotal resection, conducted due to nodularity on the dura mater, was a success and was complemented by postoperative radiation therapy. Follow-up MRIs showed no recurrence of the tumor. To the authors’ knowledge, this is the first reported case of a massive SFT involving this region, treated with minimal invasive surgery without any facial osteotomies.