Mucosa-associated lymphoid tissue lymphoma of the lung with cold-reacting autoantibody-mediated hemolytic anemia.

Mucosa-associated lymphoid tissue lymphoma (MALT-oma) of the lung is a rare low-grade B cell lymphoma arising from bronchus-associated lymphoid tissue. This report concerns a 39-year-old woman with bilateral diffuse alveolar consolidations and cold-reacting autoantibody-mediated hemolytic anemia. Open-lung biopsy showed angulated lymphoid cells with lymphoepithelial lesions. Immunocytochemistry revealed that the lymphoid cells were positive for CD19, CD20, and IgM (lambda), which was consistent with immunophenotype of MALToma. The serum immunoelectrophoresis demonstrated IgM (lambda) monoclonal gammopathy. The association of cold-reacting auto-antibody-mediated hemolytic anemia with MALToma, to our knowledge, has never been reported before in the English language.