Compressive Optic Neuropathy Caused by a Cholesterol Granuloma of the Sphenoidal Sinus.

Cholesterol granuloma is a foreign body giant cell reaction to cholesterol deposits. The pathology is rarely seen in the paranasal sinuses. In this report we describe a case of compressive optic neuropathy caused by cholesterol granuloma arising from the sphenoidal sinus. A 46-year-old lady presented with painless progressive decrease in vision in her left eye over the past 7 years. Magnetic resonance imaging of the brain and orbit with gadolinium enhancement showed a homogenous T1 and T2 hyperintense lesion causing expansion of the sphenoidal sinus compressing the ethmoidal sinus and also the left optic nerve. An endoscopic marsupialisation of the lesion was performed. Histopathological examination showed multiple characteristic cholesterol clefts surrounded by numerous multinucleated giant cells, histiocytes, lymphocytes, haemosiderin-laden macrophages, and plasma cells. This case emphasises the importance of appropriate neuro-imaging in cases of progressive optic neuropathy: cholesterol granuloma of the paranasal sinuses is a rare cause of optic nerve compression.