Unusual Findings of Benign Enchondroma in the Ulna on 3-Phase Bone Scintigraphy

Enchondroma is a common benign cartilaginous tumor arising from the medullary cavity, most commonly in the phalanges and metacarpals of the hand. Enchondroma involving the ulna is very rare. Typically, benign enchondroma shows normal or only slightly increased uptake of a bone-seeking agent on delayed bone scintigraphy. Markedly increased activity of enchondroma with pain is most often associated with pathologic fracture or malignant degeneration. The authors present the 3-phase bone scintigraphic findings of a benign enchondroma associated with pain, which showed focal hyperperfusion, hyperemia, and intense bone uptake in the distal right ulna.