Bony lesions in systemic mastocytosis: scintigraphic evaluation.

Bone, bone marrow and gallium citrate Ga 67 scans were performed on a patient with systemic mastocytosis and bony involvement to evaluate their diagnostic value in such patients. The bone scan revealed increased tracer concentration in the involved areas. These abnormalities were less prominent than those on the roentgenograms, suggesting that only a part of the roentgenographic abnormalities were associated with reactive bone formation. Bone scanning may be less sensitive than roentgenograms to detect the full extent of the bony lesions of systemic mastocytosis. The bone marrow scan revealed a normal central marrow with peripheral marrow expansion. Possibly, the central marrow infiltration by mast cells was sufficient to interfere with its hemopoietic function to a degree that made it necessary to reactivate peripheral marrow tissue. There was no significant 67Ga accumulation in the bony lesions of systemic mastocytosis.