Chondrosarcoma of the hand secondary to multiple enchondromatosis; report of two cases.

Although malignant transformation to chondrosarcoma may occur in some patients with multiple enchondromatosis, this event rarely occurs in the hand. We encountered two patients with chondrosarcoma of the hand secondary to multiple enchondromatosis. One patient was a 27-year-old man and the other, a 76-year-old man. Both patients manifested multiple osteolytic lesions in the hand on the plain radiographs. Severe bone destruction associated with a large soft-tissue swelling of the proximal and middle phalanges of the little finger was seen in case 1. In case 2, tremendous expansion and bone destruction of the middle phalanx of the ring finger was seen. Magnetic resonance images of the tumour in both patients showed low signal intensity on T1-weighted and high signal intensity on T2-weighted images. Amputation was performed in each patient. Histological examination revealed that the tumour was a grade 2 chondrosarcoma in case 1 and a grade 1 chondrosarcoma in case 2 accompanied by enchondromata. From these findings, the diagnosis of chondrosarcoma secondary to multiple enchondromatosis was made. Because quite a few patients with multiple enchondromatosis develop secondary chondrosarcoma, although rarely in the hand, the enchondromata should be curetted, unless impractical, before malignant transformation occurs.