Fine needle aspiration cytology diagnosis of aneurysmal bone cyst: a case report.

Aneurysmal bone cyst is a relatively rare tumour accounting 1 to 6% of all primary bone tumours. The involvement of clavicle is even rare with incidence of only 3% of all cases of aneurysmal bone cyst. Aneurysmal bone cyst is an expanding osteolytic lesion occurring mostly at metaphyseal ends of the long bones. Although excisional biopsy is diagnostic for aneurysmal bone cyst and FNAC (fine needle aspiration cytology) is mostly inconclusive. Still FNAC can be helpful in pre-operative diagnosis of aneurysmal bone cyst.