Angioimmunoblastic T-cell lymphoma with coexisting plasma cell myeloma: a case report and review of the literature.

Angioimmunoblastic T-cell lymphoma (AITL) is recognized as a distinct clinicopathological subtype of peripheral T-cell lymphomas. Its clinical features include generalized lymphadenopathy, constitutional symptoms, and autoimmune-related findings, such as hemolytic anemia. Pathologically, AITL is characterized by a polymorphous infiltrate in lymph nodes with prominent proliferation of high endothelial venules and follicular dendritic cells. We present an 80-year-old Chinese man with generalized lymphadenopathy and pulmonary infection, diagnosed as AITL based on the distinctive pathological findings and T-cell receptor gamma (TCR-γ) gene rearrangement analysis of lymph nodes. Importantly, the patient suffered from a coexisting plasma cell myeloma, as judged by monoclonal immunoglobulin in the serum, immature plasma cells, and rearrangement of the immunoglobulin heavy-chain (IgH) gene in the bone marrow. The patient received two courses of the chemotherapy but died of pneumonia 6 months after diagnosis. AITL can be accompanied by polyclonal or clonal proliferation of B lymphocytes; however, AITL are rarely associated with plasma cell proliferation. In fact, 14 AITL cases with plasma cell proliferation have been reported in the literature, but none of them manifested the infiltration of monoclonal immature plasma cells in the bone marrow. To the best of our knowledge, this is the first report of newly diagnosed, concurrent AITL and plasma cell myeloma, providing the evidence for the interplay between malignant T cells and plasma cell proliferation. A review of the literature has also supported a relationship between AITL and plasma cell proliferation. Awareness of this relationship is important for correct diagnosis and appropriate treatment of AITL.