Extraskeletal chondromas.

1. Extraskeletal chondromas occur in three variants: (a) as multiple nodules of synovial chondromatosis within a joint, (b) as a solitary lesion in association with articulations, within or adjacent to them, and (c) as an isolated cartilagenous lesion in the soft tissues, mostly of the hands and feet. 2. There are no histological characteristics which could differentiate articular, para-articular and soft tissue chondromas among themselves. 3. The latter two groups of extraskeletal chondromas are rare and frequently exhibit areas of immature cartilage with worrisome histologic features which could mislead the pathologist to an overdiagnosis of chondrosarcoma. 4. As a general rule, no matter how worrisome the histologic appearance of an extraskeletal, well delimited cartilagenous tumor may be, metastasis have not been recorded. Local recurrences are not infrequent after inadequate surgical removal; however, the tumor can always be controlled by adequate wide re-exision or resection. 5. Two cases of extraskeletal chondromas, one para-articular in the knee and the other in the soft tissue of the arm, have been presented with an exhaustive review of the literature on the subject. 6. It is of interest to note that our para-articular chondroma represents the first case reported in the literature where computerized tomography was utilized in the diagnosis. 7. The location of a soft tissue chondroma in the upper arm is extremely rare and only one previous case has been reported in said location.