An unusual cause of proptosis: aneurysmal bone cyst of the anterior skull base

Excerpt

A 14-year-old girl presented with mild left-sided proptosis and headache. CT revealed a multiloculated, expansile lesion in the anterior skull base. MRI demonstrated a multicystic, expansile lesion of the anterior skull base (Fig. 1), extending into the anterior cranial fossa, left ethmoid bone and clivus, and filling the left nasal passage. The left orbit was deformed with resultant proptosis. Multiple fluid-fluid levels were seen on the sagittal images (Fig. 2). After administration of gadolinium there was inhomogeneous enhancement of the central septations and the periphery. The lesion was surgically removed and histology confirmed an aneurysmal bone cyst (ABC).

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