Case 4

This is a CT study of the head, showing symmetrical expansion of the mandible. There is a lytic lesion at the mental protuberance which is expansile and causing thinning of the cortex, with internal thin bony septations giving a multiloculated appearance.  

The medullary bone of the body and rami of the mandible shows alternating areas of lysis and ground glass density matrix.

There is no periosteal reaction.

These features are characteristic of cherubism.

The differential diagnosis includes ameloblastoma- however, this typically does not involve the rami of the mandible.

Other considerations include craniofacial fibrous dysplasia, central giant cell granuloma and Brown’s tumours of hyperparathyroidism- though these are typically not bilateral and symmetrical.