[An unusual localisation of osteochondroma. A single case report].

Solitary osteochondroma is a rare benign tumour of the hand arising from the cortical surface. The important differential diagnoses, which should be considered, are Nora's lesion, florid reactive periostitis and Turret exostosis. The authors report an unusual case of osteochondroma of the metacarpal bone with a deficit of extension. The diagnosis was made using imaging techniques and confirmed by histological examination. The treatment is surgical, namely complete excision.