COMPARATIVE MICROCYTOMETRIC ANALYSIS OF EUROPEAN PERIPHERAL T‐CELL MALIGNANT LYMPHOMAS (EPTL) AND ADULT T‐CELL LEUKEMIA/LYMPHOMAS (ATLL) IN JAPAN

A simultaneous microcytometric analysis of nuclear DNA content and size was performed in 8 European peripheral T cell lymphomas (EPTL) and 8 adult T‐cell leukemia/lymphomas (ATLL), comparing their patterns on the nuclear density scattergram (NDS) of DNA content versus nuclear size. The intermingling lymphocytes with or without irregular‐shaped nuclei in EPTL and ATLL were interpreted as stimulated reactive. Medium‐sized cell‐dominated T‐zone lymphomas and ATLL pleomorphic medium‐sized cell type showed two distribution patterns in the diploid range. The first was oblique zonal cluster (OZC) with the second high concentration in the middle part of it, suggesting mixed proliferation with stimulated reactive lymphocytes, and the second was the high concentration in the lower region of the NDS with some cells corresponding to the growth fraction. In large cell‐dominated T‐zone lymphomas and ATLL pleomorphic large cell type, the third decreasing pattern in the cell density from the lower part of the OZC to its upper part was found upto the hypertetraploid range. The wide distribution on DNS and giant cells with aneuploid high DNA content were found only in the pleomorphic large cell type and the pleomorphic medium‐sized and large cell type of ATLL. The T‐immunoblastic type of EPTL showed the third pattern and the pleomorphic large cell type of EPTL, characteristic in the clear cytoplasm, showed the second pattern.