Sphenoid sinus schwannoma with adhesion to the carotid canal

Few reports have been made on the presentation and treatment of schwannomas originating in the sphenoid sinus due to their rarity. We report the case of a 60-year-old woman who presented with a cyst-like mass in the right sphenoid sinus on magnetic resonance imaging. Computed tomography showed a bone defect in the internal carotid artery (ICA) and enlargement of the round foramen on the affected side. A histopathological diagnosis of schwannoma was made, and endoscopic sinus surgery was performed. The anterior part of the tumor could be easily removed by aspiration; however, its adhesion to the ICA was remarkable, and its boundaries were unclear. Although partial paralysis of the maxillary nerve remained, no recurrence occurred for over 10 years. Careful evaluation should be performed to check for bone defects in the nerve to differentially diagnose schwannoma from cystic masses of the sphenoid sinus. Additionally, excision of masses similar to the presented case may expectedly be difficult because of unclear excisional margins and strong capsule adherence to important organs such as the ICA. Moreover, correct imaging, histopathological diagnosis, and appropriate informed consent are essential before surgery.