電顕上Zipper様構造を認め，Common ALL抗原陽性，表面免疫グロブリン陰性であったHairy Cell Leukemiaの1例

抄録

A 78-year-old male presented with splenomegaly. Leukocyte count was 15,700/μl (abnormal lymphocyte 22%), and bone marrow was normocellular (abnormal lymphocyte 10.75%). Cytochemistry revealed peroxidase negative, acid phosphatase (AP) positive, tartrate resistant AP negative. Analysis of cell surface markers revealed OKT3^-, OKT9⁺, OKT10⁺, Ial⁺, B1⁺, J5⁺, M1⁺, s^-Ig^- and Fcγ⁺, The abnormal lymphocytes were larger than those of CLL and PLL; ultrastructural mean diameter being 9.7 μm. They had ruffled membranes, many long villi and zipper-like structures. Ribosome-lamellar complex was not observed. Negativity for surface immunoglobulin and positivity for common ALL antigen were distinct from ordinary characteristics of surface markers of HCL cells. From these and ultrastructural findings, it was suggested that the abnormal lymphocytes of this case was committed in the immature B-lymphocyte near pre-B cell. Zipper-like structure has been already reported in HCL cells. It should be further investigated whether this structure is specific to HCL.