Blast Cell Leukaemia Associated with IgA Paraproteinaemia and Bence Jones Protein

Abstract

S ummary . A 47‐yr‐old housewife with myeloblastic leukaemia was found to have IgA type kappa paraproteinaemia and Bence Jones protein type kappa in her serum and urine. The possibility of two neoplastic proliferations involving both the myelocytic and the plasma cellular series was considered. However, electron microscopic and immunofluorescence investigations provided evidence that the blast cells belonged to the plasma cell series. The clinical diagnosis was changed to myeloma with leukaemia, which was confirmed at autopsy. This observation illustrates the contribution of electron microscopy and immunofluorescence to the classification of blast cells, and stresses the value of a search for paraproteins in cases of blast cell leukaemia.