Cholesterol granuloma of the orbit--pathogenesis and surgical management.

Abstract

Cholesterol granuloma of the orbit is a rare entity, and its pathogenesis is still poorly understood. We report on 6 cases including one patient who had been examined by X-ray prior to the tumor's clinical manifestation. All tumors were located in the superior temporal orbit. Histologically, they revealed the typical features of a cholesterol granuloma without any epithelial elements. They infiltrated the bone but left the soft tissues largely intact. Complete surgical removal of the granulomatous mass was attempted in each case, and particular attention was given to thorough abrasion of the bone. Only 2 patients reported a previous trauma. In one of them, retrospective evaluation of the X-ray scan taken a few hours after his accident revealed no definite changes in the orbital bone at the site of the future tumor. The only recurrence developed in a patient in whom the bony base of the tumor had not been drilled out completely. The origin of orbital cholesterol granuloma remains unknown. According to our data and those available in the literature, trauma is not a precondition but may accelerate growth. Some non-epithelial malformation in the bone, with a predelection in the temporal upper quadrant, might be the origin. To prevent a recurrence it appears essential to totally erase the tumor from its bony bed.