Arrested pneumatization of the sphenoid sinus: Report of two cases and literature review

Arrested pneumatization of the sphenoid sinus is normal developmental variant. Radiological find-ing on computed tomography (CT) or magnetic resonance image (MRI) may be confused with bony lesions of paranasal sinuses or invasive tumors of the skull base. A 43-year-old woman visited our hospital with headache, and an MRI scan performed at other hospital showed abnormal findings in the right sphenoid sinus. When the additional CT images were evaluated, it was diagnosed as an arrested pneumatization of the sphenoid sinus. A 46-year-old woman visited the neurologist with diplopia and had a brain MRI. Due to abnormal findings in the left sphenoid sinus, the patient was transferred to the otorhinolaryngology department. The left sphenoid sinus lesion was confirmed as an arrested pneumatization on CT and MRI. Both patients decided to follow-up without any special treatment. Differential diagnoses for this developmental variant would reduce treatment cost and exploratory surgery.