Analyses of CALR mutations and bone marrow morphology of the first subject. (A) Hematoxylin and eosin stain of initial marrow core biopsy and hypercellular marrow with increased megakaryocytes with variable size and shape and hyperchromatic hypolobate nuclei that are arranged in dense clustering with no overt CLL cells. (B) Reticulin stain of initial marrow biopsy with no significant increase in reticulin fibers. (C) Hematoxylin and eosin stain of follow-up marrow core biopsy after 9 years, showing megakaryocytic histotopography consistent with the prefibrotic stage of primary myelofibrosis. An increased number of small lymphocytes in aggregates are present in the upper right and lower left corners of the field, compatible with CLL (original magnification, ×40). Analysis of CALR mutations in exon 9 was performed by fragment analysis, which is a semiquantitative analysis.3 (D) Fragment analysis of CALR from granulocytes obtained 3 years after diagnosis of type 1 CALR deletion. (E) Fragment analysis data of current granulocyte DNA (9-year follow-up after diagnosis), with the same CALR deletion. (F) Fragment analysis of DNA from CD19+ cells; the type 1 CALR deletion is not present.
