Unusual radiographic presentation of an aneurysmal bone cyst of the mandible

An 11-year-old girl was referred because of a painless firm swelling in the right posterior mandible that had started 2 months previously. A panoramic radiograph showed a nonspecific finding of a tiny discreet shadow following the lower border of the mandible, without any radiographic signs of radiolucency in the affected area or discontinuity of the lower border. However, multislice computed tomography (MSCT) findings were suggestive of an aneurysmal bone cyst, and histopathological findings revealed a diagnosis of aneurysmal bone cyst. Complete surgical excision followed by extensive cortical bone curettage was done, and no recurrence has been observed in the past 5 years. A differential diagnosis list is included, and extended with fibrous dysplasia according to the radiographic findings. To the best of our knowledge, this is the first case of a jaw aneurysmal bone cyst with unusual initial radiographic findings. Furthermore, a ground-glass appearance on MSCT scans suggested fibrous dysplasia. The present case highlights the need for accurate differential diagnosis of the lesion described to obtain the correct diagnosis in a timely manner and plan the appropriate treatment.