Not all cases of idiopathic thrombocytopenic purpura [correction of pupura] are what they might first seem.

We present the case of a patient diagnosed as having presumed idiopathic thrombocytopenic purpura (ITP) who subsequently developed chronic myelomonocytic leukaemia (CMML) after an interval of 16 months. A variety of peripheral cytopenias are commonly seen in myelodysplastic disorders (MDS), and autoimmune phenomena, including secondary ITP, are well described, especially in cases of CMML. We would advocate evaluation for possible MDS/CMML by morphological examination of the peripheral blood/bone marrow in adult patients presenting with isolated thrombocytopenia, especially if there is subsequent development of additional peripheral cytopenias, monocytosis or hepatosplenomegaly.