Giant pediatric aneurysmal bone cyst of the occipital bone: a case report and review of the literature

Aneurysmal bone cyst (ABC) is a rare tumor-like vascular bone lesion that usually affects the metaphyses of the long bone. Cranial ABCs are uncommon, and occipitoparietal bone involvement is extremely rare. This lesion was first described by Jaffe and Lichtenstein in 1942. The precise etiology and pathophysiology of ABCs remain uncertain.
A 7-year-old boy with a history of occipital swelling, headache, and recurrent bleeding at the swelling site following trivial trauma presented to the clinic. Computed tomography revealed a huge, expansile, multiloculated cystic lesion. The patient had en-bloc resection of the mass and cranioplasty. Histopathology confirmed the diagnosis of ABC. The patient remained stable with no recurrence at the 6-month follow-up. Differentiation of ABC from other osteolytic lesions of the cranium is difficult. However, a computed tomography scan showed the characteristics of the lesion. A high index of suspicion and imaging are important to diagnose ABC of the cranium as an extremely rare entity.