Maxillary Schwannoma: A Case Report

Abstract

Background: A schwannoma is a benign, typically slow-growing tumor originating from Schwann cells in the peripheral nervous system. Although nearly half of all schwannomas manifest in the head and neck, they rarely involve the sinonasal tract, and primary origin within the maxillary region is even more exceptional. Due to a lack of unique clinical symptoms, maxillary schwannomas are frequently misdiagnosed preoperatively as common sinus infections, dental problems, or malignant tumors. Case Presentation: This report details the case of a 34-year-old female who presented with a progressive sequence of right-sided symptoms starting in 2024 with blurred vision, facial numbness, and altered tactile sensation. By early 2026, her condition worsened to include severe nasal blockage, recurrent epistaxis, facial swelling, buccal numbness, diplopia, and proptosis. Advanced diagnostic imaging, including contrast-enhanced MRI and non-contrast CT scans, revealed a large 63 x 43 x 41mm multi-cystic mass originating from the right pterygopalatine fossa. The tumor extended extensively into the right maxillary sinus, causing significant scalloping and erosion of the sinus walls and orbital floor, which resulted in the compression of the extraocular muscles and the optic nerve. An endoscopic biopsy and subsequent histopathological and immunohistochemical examinations confirmed the diagnosis of a benign maxillary sinus schwannoma, demonstrating characteristic spindle cells with nuclear palisading, Verocay bodies, and strong positivity for S-100 protein. Management and Outcome: In April 2026, the patient underwent a successful surgical intervention utilizing a combined transfacial excision and endoscopic clearance under general anesthesia. This dual approach allowed for complete tumor clearance from hidden recesses while managing the complex boundaries of the pterygopalatine fossa and orbital floor. The resulting bony orbital floor defect was reconstructed using a 1.5 mm titanium orbital mesh secured with titanium screws. The patient’s post-operative recovery was largely unremarkable. Expected minor, localized post-operative sequelae included right eye epiphora, a transient burning sensation from digital screens, and occasional mild swelling, which were appropriately managed. Conclusion: Maxillary schwannomas present unique diagnostic and therapeutic challenges due to their insidious onset and tendency to mimic more common inflammatory diseases or aggressive malignancies. This case highlights that multi-modality imaging (MRI and CT) and preoperative biopsy with immunohistochemistry are essential for precise planning and confirmation. Ultimately, a tailored surgical strategy combining transfacial and endoscopic approaches provides maximal tumor clearance and structural reconstruction while ensuring an excellent long-term prognosis.