Peripheral Blood -- Lymphocytosis


The CBC showed a normochromic normocytic anemia, leucocytosis and mild thrombocytopenia. The peripheral smear Figs 1, 2, 3, 4 and 5) showed a lymphocytosis, with most of the cells classified as atypical lymphocytes. These were small to intermediate in size and blastic-appearing, with a high nucleo-cytoplasmic ratio (N:C), primarily condensed nuclear chromatin and variably prominent nucleoli. The nuclear contours were rounded or slightly convoluted. The cytoplasm was scanty, slightly basophilic, and vacuolated. No granules were seen. Some cells were very large with slightly more open chromatin and prominent small nucleoli, while others had very prominent nuclear grooves or clefts. The RBC morphology was remarkable for 1+ anisocytosis, 1+ macrocytes and 1+ microcytes.


The bone marrow aspirate smears were cellular (Figs 6, 7, 8 and 9) and biopsy (Figs 10, 11, 12, 13 and 14) was markedly hypercellular (greater than 90%), with an extensive diffuse lymphoid infiltrate. The cellularity consisted mostly of lymphoid cells (classified as blasts) which were variable in size from intermediate to very large with a high N:C ratio, condensed chromatin and indistinct nucleoli. Nuclear contours were rounded as well as irregular or slightly clefted. Vacuoles were occasionally noted in the cytoplasm. Increased mitotic activity was present. Erythroid elements were rarely seen. Myeloid maturation was present and was megaloblastoid. Megakaryocytes were present in normal to focally decreased numbers. The bony trabeculae were unremarkable.

In order to further characterize the lymphoid cells, paraffin section immunohistologic studies were performed on the bone marrow biopsy. The following results were found:





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