Sphenoclival Intraosseous Lipoma: A Typical Lesion at an Atypical Location.

In this report, we present the case of a rare tumor in the sphenoclival region and discuss the potential pitfalls in its diagnosis and management. Intraosseous lipoma is a rare benign tumor, mostly accounting for 0.1% of all bone tumors. The disease is usually asymptomatic and mainly involves the hips, vertebrae, ribs, and metaphysis of the long bones. However, the intraosseous lipoma of the skull is less common, especially with few cases having been reported to involve the sphenoid bone in the literature. We present a rare case of sphenoclival intraosseous lipoma in a 28-year-old female who presented with a history of chronic headache. A non-contrast computed tomography (NCCT) was ordered, which revealed a deviated nasal septum with thickening of bilateral ethmoidal sinuses with mastoiditis and a well-defined fat-containing intraosseous lesion in the clivus with a mean HU~ of -32 with few septations within. The risk of malignant transformation in intraosseous lipoma is very low. The differential diagnosis of intraosseous lipoma includes end stage of infection, infarct lesions, intraosseous meningioma, angiolipoma, and myxofibrous tumors.