[Chronic osteomyelitis - a diagnostic dilemma]

Infective skeletal lesions can mimic bony tumours. Bony lesions without periosteal reactions in adult patients with normal leucocyte counts will have a different differential diagnosis from that of children with bony lesions and a periosteal reaction. In the latter, osteomyelitis should be distinguished from Ewing's sarcoma and osteogenic sarcoma. Due to the difficult preoperative diagnosis a retrospective study was undertaken which included 14 patients with the histological diagnosis of chronic osteomyelitis but normal leucocyte count and no periosteal reaction. Radiographs showed cavities in 82%, infiltration in 12% and sclerosis in 6% of cases. All patients who underwent skeletal scintigraphy studies showed increased uptake in the lesions. Magnetic resonance showed increased signal intensity in T2 images. Ordinary radiographs are still the most valuable primary investigation for skeletal lesions.