RIB - Fibrous dysplasia of bone

The specimen consists of a bisected mass firmly adherent to the 6th, 7th and 8th ribs. The mass consists of a variegated tumour which has numerous large multiloculated cysts in the central portion. Several other areas of cyst formation are seen throughout the tumour, these are associated with haemorrhage. The lesion appears to be continuous with the medullary cavity of the ribs. Histologic examination of the specimen showed a dense mass of fibrous tissue containing numerous immature boney trabeculae. The microscopic features are diagnostic of fibrous dysplasia of bone.
The patient, a 62 year old male, presented as an arranged admission for the removal of a mucocoele of the frontal sinus. During the routine preoperative workup a mass was noted on chest x-ray. Review of x-rays showed the mass had been present 25 years earlier, but had been slowly growing over this period. Surgical excision of the mass was undertaken and the patient made an uneventful recovery.