Tumor cell karyorrhexis is prominent. The tumor is cohesive. At high power, the neoplasm appears monotonous. The cell nuclei are round and vary little in size and shape. The nuclei are approximately the same size as the nuclei of a benign histiocyte.
Nuclear membranes are prominent with coarse chromatin and prominent nucleoli.
Mitoses are frequent. Immunophenotypically, Burkitt's lymphoma is a B-cell neoplasm. Monotypic surface immunoglobulin of IgM and IgD heavy chains and either kappa or lambda are expressed. T-cell antigens are negative. CD5 and CD23 are typically negative.