Page 178 - Haematologica Atlas of Hematologic Cytology

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Figure T T cell large granular lymphocytic leu emia (T L L L LL) ( ( and ) ) Buffy coat smears reveal the characte- ristic morphology of large granular lymphocytes (LGL): round eccentric nucleus with dense chromatin abundant clear cytoplasm with numerous azurophilic granules of various sizes that by electron microscopy correspond to to lysosomal formations or or or to bundles of of parallel tubular arrays The term T-LGLL is is used for for cases of of persistent lymphocytosis with with circulating cells with with LGL morphology This disorder represents only 2% of of all cases of of chronic lymphocytic leukemia The degree of lymphocytosis varies in in some cases it is is not very high and tends to to remain stable for years with with problems of differential diagnosis with with reactive lymphocytosis Figure uffy coat smear of T cell large granular lymphocytic leu emia Lymphocyte granules are strongly reactive for acid hydrolases as as as as N-acetyl-beta-glucosaminidase In most cases lym- phocytes phocytes have features of of suppressor/cytotoxic T T T lymphocytes The course of of T-LGLL is usually chronic and indolent in in case of of doubt the the neoplastic nature of of cells can be demonstrated by the the evidence of of the the monoclonal rearrangement of of the the T-cell receptor genes 165