日本人のCLLならびに類縁疾患の特徴

抄録

The clinical and cytological features of 73 patients with chronic (mature) B-cell leukemias were studied. Large lymphocytes or cleft cells were often seen in patients referred to us as chronic lymphocytic leukemia (CLL). Immunophenotypical and histopathological studies were performed and the diagnosis of leukemic phase of non-Hodgkin's lymphoma (follicular lymphoma; FL and intermediate lymphocytic lymphoma; ILL) was made in a significant portion of the patients and only ten cases were diagnosed as CLL including mixed cell type.
Although hairy cell leukemia (HCL) is quite rare in Japan, a disproportionally large number of patients were referred to our laboratory. Typical HCL seen in Western countries, was found in nine cases. On the other hand, most (29 cases) showed cytologic features distinct from typical HCL and were classified into HCL-Japanese Variant (HCL-J). Morphology of HCL-J cells in May-Giemsa stained films resembled large CLL lymphocytes, but several features shared by typical HCL and HCL-J including typical hairy morphology under phase contrast microscopy, CD11c⁺, L30^- phenotype and the histology distinguished the disease from CLL and other B-cell leukemias. In two cases, the cells displayed prominent nucleoli and surface villi, the features consistent with those described for HCL Variant (prolymphocytic variant). Some patients were differentiated from HCL and were diagnosed as leukemic phase of ILL with large spleens or splenic lymphoma with villous lymphocytes (SLVL). Under phase contrast, fine cytoplasmic processes were obseved in ILL cells. Surface morphology of SLVL cells considerably varied from cell to cell; some displayed prominent cytoplasmic projections similar to those of hairy cells, while others had a few, short villi or lacked villi even by phase contrast microscopy. The spleen histology showed prominent involvement in the white pulp with the features of lymphoplasmacytic lymphoma.