Primary eosinophilic granuloma invading the skull base: case report and critical review of the literature.

A case of eosinophilic granuloma of the lesser wing of the sphenoid bone is reported. The patient was a 5-year-old white male, with left temporal-frontal headache, left III cranial nerve palsy, left exophthalmos and ptosis caused by an osteolytic lesion of the anterior clinoid process extending to the left optic canal and cavernous sinus. The patient underwent surgical resection of pathologic tissue. Pathologic diagnosis was eosinophilic granuloma of the sphenoid bone. Surgical management, postoperative prognosis and differential diagnosis of eosinophilic granuloma of the skull base are discussed along with a review of the literature.