[Intratumoral hemorrhage of cholesterol granuloma in the frontal bone showing rapid progressive symptoms: a case report].

A 30-year-old man developed an exopthalmus in his right eye and diplopia at upward gaze those were progressive in two days. On admission, his upper eye lid in the right eye swelled and upward gaze was limited in the right eye. CT scan showed an osteolytic lesion in the right frontorbital bone. MR imaging showed a high signal tumor in both T1- and T2-weighted imaging with sharp margin and no enhancement. Right frontal craniotomy was performed and the cystic tumor consisting of old hematoma, and soft tissue surrounding the cyst was totally removed. The orbital roof had a large defect and tumor compressed periorbita. Neither communication with the frontal sinus nor mucosa with inflammation were seen. The postoperative course was uneventfull and pathological diagnosis was cholesterol granuloma with hematoma. Orbitofrontal bone is a rare site to have cholesterol granuloma. Most of them are asymptomatic. In our case, intratumoral hemorrhage caused compression on the perioribital, leading to a progressive mass sign. Preoperative differential diagnosis from other orbital tumors, such as epidermoid and lipoma was difficult.