Malignant tenosynovial giant cell tumor of the leg: a radiologic-pathologic correlation and review of the literature.

Malignant tenosynovial giant cell tumor (TGCT) is a rare clinical entity that can arise as a recurrent lesion or can co-exist with a benign TGCT lesion. Malignant TGCT most commonly arises in the lower extremity and tends to be clinically aggressive, with most patients developing recurrent lesions or dying. Much of the literature describes the histopathologic features and classifies this broad group of tumors, with little description of the imaging characteristics of this disease. We present the multimodality appearance of a case of malignant diffuse-type TGCT that recurred 2 months after resection with subsequent rapid clinical progression.