A RETROSPECTIVE ANALYSIS OF BONE-SCAN ABNORMALITIES IN MASTOCYTOSIS -CORRELATION WITH DISEASE CATEGORY AND PROGNOSIS

To investigate the usefulness of bone scintigraphy in systemic mastocy tosis (SM), the scans of 73 patients were retrospectively reviewed and correlated with disease category. Methods: A modification of a previo usly described method for bone scan classification in this disease was used. In addition to the group as a whole, two subsets of patients wi th multiple bone scans were identified for closer analysis: those with (n = 13) and without (n = 12) scintigraphic evidence of progression o f disease. Results: Overall, patients with more aggressive SM tended t o have increasingly abnormal initial bone scans (p2 = 0.0003), althoug h there was a considerable degree of overlap. Of patients undergoing s erial studies, those with scintigraphic progression also tended to hav e more aggressive disease (p2 = 0.006) and a poorer prognosis than tho se with stable bone scans. Conclusions: Both the degree of abnormality on initial bone scan and progression of scintigraphic abnormalities w ith serial scanning appear to correlate with the presence of more aggr essive systemic mastocytosis. Based on the patterns seen, in many case s this may be a reflection of bone marrow expansion, which in turn pro bably reflects increased marrow disease.