"Bone marrow-liver-spleen-type diffuse large B-cell lymphoma" presenting with cold autoimmune hemolytic anemia: a case report.

Introduction: Primary bone marrow diffuse large B-cell lymphoma is a rare clinical entity, and the "bone marrow-liver-spleen" type of diffuse large B-cell lymphoma is rarer, with only a few published cases in literature. Though bone marrow-liver-spleen-type diffuse large B-cell lymphoma has unique presentations such as fever, cytopenias, and hemophagocytic lymphohistiocytosis, no cases with cold autoimmune hemolytic anemia have been reported.

Case presentation: A 39-year-old Sri Lankan woman, previously healthy, presented with shortness of breath, productive cough, and fever for 4 days. Examination revealed pallor, icterus, and massive hepatosplenomegaly with no peripheral lymphadenopathy. Further investigation revealed pancytopenia (hemoglobin 58 g/L, white blood cell count 1.73 × 10⁹/L, platelets 23 × 10⁹/L, a reticulocyte index of 4.43%, and lactate dehydrogenase levels of 1690 U/L). Blood picture analysis was suggestive of hemolytic anemia, which was confirmed by a positive direct antiglobulin test with anti-C3d. The bone marrow biopsy revealed markedly hypercellular marrow with polymorphic infiltrate of mononuclear cells accounting for about 80-85% of nucleated cells. These cells were predominantly medium to large cells in size with scanty cytoplasm, irregular nuclear margins, prominent nucleoli, and many mitotic figures. These mononuclear cells were positive for immunohistochemical markers of CD20, BCL2, and CD10. The Ki-67 index was 24%. In addition, this patient had cold autoimmune hemolytic anemia. Contrast-enhanced computed tomography of the chest, abdomen, and pelvis revealed homogeneously enlarged liver and spleen with no significant lymphadenopathy. These findings were compatible with the diagnosis of bone marrow-liver-spleen-type diffuse large B-cell lymphoma. The patient was referred for specialized oncological management.

Conclusion: Though there are reported cases of primary bone marrow diffuse large B-cell lymphoma presenting with cold autoimmune hemolytic anemia, no such cases of bone marrow-liver-spleen-type diffuse large B-cell lymphoma have been reported. As this unique entity has a rather grim prognosis, it is of utmost importance to identify it early and treat aggressively. Owing to the limited availability of published accounts of this uncommon disease, we believe it is important to document our case to add to the understanding of this rare condition and its various presentations, which can easily be misinterpreted.