RESUMO
The number of well-documented true giant cell tumours arising in any of the craniofacial bones is small, but they do exist. A 19 year old female, Ms. KS, presented with complain of progressive enlargement of facial bones especially jaw bones, then orbit symmetrically since the age of 7. There was bilateral gross enlargement of mandible, maxilla, orbital walls, causing displacement of eye medially and upwards. The visual acuity of both eyes were 6/36 and 6/18 with best correction. Extra ocular movements were restricted because of bony growth and conjunctiva over inferior fornix were keratinized due to exposure. Fine needle aspiration (FNAC) from the side of bony growth showed plenty of osteoclasts with multinucleated giant cells. The level of serum alkaline phosphatase were highly increased. She underwent orbitotomy and a part of tissue was sent for biopsy which revealed multiples of mononucleargiant cells and tumour cells.