"Prolymphocytic leukemia" （Galtonら）に近似せると考えられる異型リンパ球の著増を来した2例

Case 1: A 38-year-old housewife was admitted to our clinic on January 1973 because of fever and lymphocytosis of 4-months' duration. Leukocytosis (25,500/m㎥) with a marked lymphocytosis (70%) was present in peripheral blood. Twenty-four out of this 70% of lymphocytes were markedly atypical, showing indented or lobated nuclei and rather abundant basophilic cytoplasm. These cells were also seen in bone marrow in 2.6%. Phase contrast and electron microscopic observation revealed these cells to be rather mature atypical lymphocytes. Negative Paul-Bunnell test, low antibody titer for EB virus, and poor blstogenesis to stimulation by phytohemaggulutinin and T-cell nature of these lymphocytes were demonstrated. Prominent hepatosplenomegaly was characteristic though lymphoadenopathy was absent. Peripheral leukocyte counts increased progressively up to 20.4×10(4)/m㎥ while blasts were scarecely seen. In spite of administering Neocarzinostatin, vincristine and prednisolone. the patient died of pneumonia three months after admission. Necropsy using a Silverman needle revealed cytomegalic inclusion bodies in the lung and massive infiltration of, what appeared to be, atypical lymphocytes into the liver, spleen and kidney. Case 2: A 56-year-old male was admitted to the Okayama University Hospital at Misasa on March 1974, complaining of high temperature of 2-weeks' duration. Leukocyte counts in peripheral blood was 7,550/m㎥ with atypical lymphocytes, which were quite similar in shapes as well as in maturities to those seen in the Case 1 and were seen in 23.5%, whereas they were 7.8% in the bone marrow. Fever continued without responding to various antibiotics and prednisolone. Leukocyte counts were increased up to 23,600/m㎥ within two weeks and he died of massive interstitial pneumonia one month after the admission. Necropsy with a Silverman needle revealed cytomegalic inclusion bodies in the lung and infiltrations of atypical lymphocytes into the liver, spleen and kidney. Infectious mononucleosis can be ruled out on the basis of progressive and fatal clinical courses and other specific laboratory findings, although infection by Herpes type virus might play some role at the terminal stage of the disease. As the increase of atypical lymphocytes is so prominent in the peripheral blood and bone marrow, these 2 cases probably belong to lymphocytic leukemia; acute lymphocytic leukemia can easily be omitted because no blasts were seen. On the other hand, these cases cannot be categorized as conventional chronic lymphocytic leukemia in various points, showing atypical lymphocytes with variegated shapes and sizes, much shorter surviving time than that and poor response to therapy. Differentiation of these cases from "lymphosarcoma cell leukemia" is also made by their shorter clinical courses than that leukemia and absence of very characteristic nucleoli seen in that leukemia. Maturity of the cells from our cases also differ from those in lymphosarcoma cell leukemia; cells in our cases are maturer than those of that leukemia. "Prolymphocytic leukemia" reported by Galton et al. may be a disease entity to be most compatible with our cases. Marked lymphocytosis, short survival time, poor response to therapy, hepatosplenomegaly and absence of peripheral lymphoadenopathy accord well with the clinical features described by them. The characteristic cells, however, in the peripheral blood of prolymphocytic leukemia are somewhat different from those seen in our cases. The cells of that leukemia have a large vesicular nucleolus in almost every cases without appreciable clefts, indentations or lobations of nucleus, whereas less conspicuous nucleoli and more irregular nuclei in shape were frequently observed in our cases than in prolymphocytic leukemia. Incidentally, Akihama et al. reported a case quite resembling our cases, and proposed a new clinical entity which should be differentiated from chronic lymphocytic leukemia due to several reasons as stated before. Because of, however, the lack of proper autopsies and limited numbers of cases experienced so far, it will be too premature to state that these 3 cases, including that of Akihama et al., should be regarded as a new clinical entity. Further studies on the similar cases to ours will be needed to decide as to whether or not our 2 cases are indeed a variant of prolymphocytic leukemia.