Introduction A 69 year gentleman who presented to the emergency department with complaints of fatigue and bleeding since 2 days. On examination he was pale and had multiple significant lymphadenopathy in the cervical and the inguinal region largest measuring 2x2 cm. His routine biochemistry and hematological investigations were done. His hemoglobin was 8.8 g/dl and total WBC count was 16.69 thous/µl and platelet 24 thous/µl. peripheral smear examination showed many atypical (65%) lymphoid cells which are medium to large sized with significant nuclear cleaving and prominent nucleoli in a few. LDH was increased to 450 IU. And other routine biochemistry investigations were normal. Bone marrow aspirate and bone marrow biopsy was done along with flowcytometry Immunophenotyping.Bone marrow aspirate was a dry tap and only imprint smears were obtained. Imprint smears are cellular with many (74%) atypical medium to large lymphoid cells with nuclear cleaving and prominent nucleoli. Features were consistent with leukemic spillover of a Non-Hodgkin’s lymphomaFlow cytometry findings – Flow cytometry Immunophenotyping showed a population of B cells which expressed CD20, CD38, CD5, HLADR, CD23, CD49d, CD22, CD24 and showed Lambda light chain restriction. Negative for CD200, C10 and Other markers of immaturity and T and myeloid cell differentiation. The morphologic and immunophenotypic features suggest a possibility of a leukemic spill over of a Mantle cell lymphoma.Bone marrow biopsy was adequate and hypercellular with infiltration by sheets of atypical lymphoid cells which are medium to large sized with few showing prominent nucleoli consistent with infiltration by Non-Hodgkin’s lymphomaLymph node core biopsy from inguinal region done showed sheets of atypical lymphoid cells which are medium to large sized with nuclear indentation. On immunohistochemistry, these cells are positive for CD20, CD5, BCL2, and SOX 11 and negative for CD 23, Cyclin D1, BCL6, MUM1, and C-myc. The morphological and immunoprofile shows features of cyclin D1 negative  mantle cell lymphoma