ABSTRACT
This study aimed to report a rare case of occipital aneurysmal bone cysts [ABCs] in an adult patient. ABCs account for 1% of primary bone tumors. They are usually seen in pediatric age and rare in adults. They are benign fibro-osseous lesions, but they also tend to double in size rapidly and destruct the morphology of the bone. They have a tendency to extend to the long bones and vertebral column. The calvarial ABCs are 3%-6% of ABC. They usually affect the frontal and temporal bones of the skull, and cranial nerve findings are frequently seen. In the adulthood, occipital ABCs are extremely rare. Sixteen cases of occipital ABC, average age 15 years, have been reported in the literature. A 50-year-old female patient was admitted to the clinic with the history of an occipital mass lesion, which had been growing for 6 months. Magnetic resonance imaging and computed tomography of the cranium revealed an irregular-shaped destructive lesion of 55 × 18 × 28 mm3 in the diploe part of the occipital bone. The mass with an approximately 6 cm radius, and 1 cm normal bone edge was completely excised. Because of total resection, no adjuvant therapy was performed. Neither recurrence nor residual lesion was observed in the postoperative 24 months