Primary bone marrow lymphoma presenting with cold-type autoimmune hemolytic anemia

We report a rare case of primary bone marrow lymphoma with cold-type autoimmune hemolytic anemia (AIHA). A 70-year-old Japanese woman with suspected liver disorder presented to our hospital with palpitation. On physical examination, she had jaundice and signs of anemia. No lymphadenopathy or hepatosplenomegaly was noted. A direct antiglobulin test was positive for complement C3b and C3d. Anti-IgG testing was negative. Cold agglutinin was positive with a titer of 1:≥8,192, and haptoglobin was absent. A diagnosis of cold-type AIHA was made. Bone marrow biopsy revealed involvement with a population of lymphocytes that were positive for CD20 (L-26), CD79a, and Bcl-2. No lymphoma lesion was detected on computerized tomography or on upper and lower endoscopy. The patient was diagnosed with diffuse large B cell lymphoma (DLBCL) presenting with cold-type AIHA. She was treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone, resulting in complete remission after six cycles. As of 22 months after presentation, no signs of cold-type AIHA or lymphoma were present.