Objective: We report an unusual presentation of telangiectatic osteosarcoma of distal femur in a preadolescent boy.

Methods: A 9 year old boy fell down heavily while he was on holiday and fractured his distal femur. He was given above knee plaster locally and then transferred him to hospital where he lives normally. He developed increasing pain over next two weeks over fracture site (4 weeks after injury) and was reviewed in clinic. X ray of his femur showed permeative pattern of bone destruction with new bone formation. Subsequent biopsy of his lesion confirmed telangiectatic osteosarcoma. His subsequent MRI scan of thigh and CT scan of his chest showed pulmonary metastasis and dissemination of tumour to proximal femur. He never noticed any pain, discomfort or swelling before fracture and until four weeks after fracture apart from symptoms of fracture. Retrospective review of his x ray which was taken at the time of fracture demonstrated not very obvious osteolytic lesion in distal femur.

Conclusion: Telangiectatic osteosarcoma is a rare subtype of osteosarcoma and represents nearly 2% of all osteosarcomas. The incidence peaks in early to mid-adolescence and is not commonly encountered in very young and preadolescent patients.

Osteosarcoma usually presents with pain at night and precedes tumour by weeks or months. Some times there may be only a history of a tired feeling, a slight limp or a history of trauma.

Our case did not have any symptoms at all until two weeks before the presentation. The fracture made the tumour extra compartmental and led to metastasis and poor prognosis. We should always aware of this possibility of rare presentation when we see a preadolescent patient with increasing pain following fracture.