The Diagnostic Dilemma of a Rare Solid Aneurysmal Bone Cyst Imitating Monostotic Fibrous Dysplasia of the Mandible: Case Report

An aneurysmal bone cyst is a benign bone lesion that typically affects long tubular bones and the spine, with the extremely rare cranio-maxillofacial (CMF) involvement. In the CMF region, they have non-specific features causing rapid expansion of the involved bone with thinned out cortices and facial asymmetry. We present an absolute rare, solid variant of aneurysmal bone cyst which mimicked clinical and radiological presentations of fibrous dysplasia in a child, which was eventually confirmed with histopathology. Considering the age, the lesion was surgically treated via curettage and peripheral ostectomy with no recurrence and good bone healing noted till 18 months follow up. In the surgical management of a solid aneurysmal bone cyst, factors such as the patient's age, the lesion's location and extent, as well as any aesthetic and functional limitations should always be considered.