Extraskeletal osteochondromas of the wrist.

Extraskeletal osteochondromas of the wrist are described in two patients. They both had painless, slow-growing wrist masses, one palmar and one dorsal. Radiographs demonstrated the presence of an extraskeletal, radiopaque mass. Excisional biopsy showed extraskeletal, firm, calcified masses. Histologic examination revealed mature hyaline cartilage, with extensive ossification consistent with the diagnosis of extraskeletal osteochondroma. The ambiguous nomenclature for this cartilage lesion and the differential diagnosis of extraskeletal calcification are reviewed.