Juvenile psammomatoid ossifying fibroma with aneurysmal bone cyst in the posterior mandible.

Aneurysmal bone cysts (ABCs) are a rare benign lesion seen as locally destructive, rapidly expansile, and mostly affecting the long bones and vertebrae. The association of ABCs with juvenile psammomatoid ossifying fibroma (PsJOF) is predominantly seen in the extragnathic region, and it is extremely rare with only a few cases reported so far in the mandible. Here, we report one such case of a hybrid lesion in a seven-year-old boy, who presented with a solitary swelling of the left mandible showing partial obliteration of buccal vestibular sulcus, which shows juvenile psammomatoid ossifying fibroma as a pre-exsiting lesion, transforming into an ABC. Such hybrid lesions are usually misdiagnosed and have been sparsely reported in the dental literature.