SMZL stands for "splenic marginal zone lymphoma", a type of lymphoma originating from the spleen.Consequently, this patient had a significantly enlarged spleen of ~20cm (normal is ~10cm). The malignant lymphocytes are morphologically very similar to Hairy cells (HCL) and in terms of localization very similar to those of the Mantle cell lymphoma (primary in the spleen, MCL). Therefore, the final diagnosis relies mainly on the exclusion of the other forms (diagnosis per exclusionem) through morphology, flow cytometry and localization. HCL is excluded by the absence of CD23, CD25 and CD103. MCL by the absence of CD10.