RESOLUTIVE PANCYTOPENIA WITH EFFECTIVE TR EATMENT OF HYPERTHYROIDISM

Hyperthyroidism can be associated with various haematological disorder s related to several mechanisms, These disorders might be related to t he reduced life-span of whole blood components and/or to an autoimmune mechanism, Only one case of pancytopenia has yet been reported, The o bservation of 3 new personal cases (1 toxic adenoma and 2 Graves' dise ase) led us to review the pathogeny of haematological disorders found in hyperthyroidism. Only one patient had antineutrophil autoantibodies , Direct and indirect Coomb's test, and Dixon's test were negative, In all patients, bone marrow aspiration was unable to demonstrate pernic ious anaemia or myelodysplastic syndrome, Two patients presented cytol ogical signs of macrophage activation with eosinophilia, These cytolog ical features were compatible with an immuno-allergy mechanism, All ha ematological disorders disappeared when patients became euthyroid, In all cases, the haematological abnormalities were quite mild and might have gone unnoticed, Thus, it can be suggested that the frequency of p ancytopenia in hyperthyroidism is underestimated.