Source:http://linkedlifedata.com/resource/umls/id/C1266168
NCI: An uncommon malignant tumor arising from the tendon sheath. Morphologically, it is characterized by the presence of a cellular infiltrate reminiscent of a giant cell tumor with prominent malignant characteristics. Recurrent giant cell tumors with a sarcomatous dedifferentiation are included in this category as well.,NCI: A benign giant cell tumor of tendon sheath characterized by a proliferation of synovial-like mononuclear giant cells and multinucleated giant cells with areas of overt malignancy. Alternatively, this may tumor may present as a sarcoma recurring in the site of a previously diagnosed typical giant cell tumor.