Diffuse mineralization of forearm extraskeletal chondroma.

We report on the clinical, histologic, and radiologic features - including CT and MRI - of extraskeletal chondroma in a rare case of diffuse calcification of the chondroid matrix. T2-weighted MR imaging showed a well-demarcated mass of low signal intensity in the left flexor digitalis profundus, with a slight surrounding intramuscular edema. Histopathological examination revealed a heavily calcified soft-tissue chondroma generating macrophagic foreign body reaction. Knowledge of this unusual pattern of mineralization may help in the radiological diagnosis of extraskeletal chondroma.