MYOSITIS-OSSIFICANS CIRCUMSCRIPTA WITHOUT A HISTORY OF TRAUMA IN A CHILD - REPORT OF ONE CASE MIMICKING A MALIGNANT-TUMOR

A ten years nine months old girl was admited to hospital for a painful inflammatory tumour of the right popliteal area. There was a calcific ation on X-ray and computerised angiography showed a tumour. MRI showe d a heterogenous irregular mass. This looked like a malignant tumour.A t surgical biopsy: it was a circonscripta myositis ossificans. This be nign tumour of soft tissues, rare in children (25 cases in the literat ure), had a spontaneous favourable evolution. Differential diagnosis w ith malignant tumour is well known, but is still difficult. Biopsy is necessary in doubtful cases. We had to remove the mass because of acut e pain.