An Aggressive Maxillary Antral Aneurysmal Bone Cyst in a Young Woman: Unusual Presentation in an Uncommon Location

Background: Aneurysmal bone cyst (ABC) is a rare, osteolytic and cystic bone tumour that uncommonly involves the jaw bones. Adolescents and young adults are commonly affected. It usually presents as a primary neoplasm but sometimes as a secondary disease, in association with other pathological entities. Case Presentation: We report an aneurysmal bone cyst of the maxillary antrum in a 30-year-old woman who presented on account of painful right maxillary swelling of 6 months' duration. Computerized tomographic scan revealed right maxillary antral wall destruction by an expanding cystic mass. Histopathologic evaluation revealed an irregularly shaped cystic to fleshy tissue, and transection felt hard to gritty, revealing nodular to cystic and haemorrhagic areas. Microscopic findings showed multiple blood- filled to empty cysts delineated by thin to thick fibrous septae lined by myofibroblastic spindle cells with a wall having scattered osteoclast-like giant cells and inflammatory cells. Conclusion: We recommend close follow-up of the patient because of the relatively high rate of recurrences for the incompletely excised tumours.