Co-occurrence of angioimmunoblastic T-cell lymphoma and aggressive-refractory plasma-cell neoplasm: Two new cases and literature review.

Angioimmunoblastic T-cell lymphoma (AITL) is a rare and aggressive peripheral T-cell lymphoma of T-follicular helper (TFH) cell origin, characterized by systemic manifestations, immune dysregulation, and frequent secondary B-cell proliferations. While Epstein-Barr virus (EBV)-related diffuse large B-cell lymphoma develops in up to 20% of AITL cases, the occurrence of overt plasma cell neoplasms such as multiple myeloma (MM) has been documented only in isolated reports. We describe two new patients with AITL complicated by highly aggressive, treatment-refractory plasma-cell neoplasia, including the first documented case of primary cutaneous myeloma, and provide a comprehensive review of all published cases of concurrent systemic T-cell lymphoma (TCL) and plasma-cell neoplasm. A systematic search of PubMed, Web of Science, and Google Scholar identified 16 previously reported cases, yielding a total of 18 patients. These included several TCL subtypes. In most cases, the plasma-cell neoplasm occurred synchronously or shortly after TCL diagnosis. Approximately 50% of patients had an IgA paraprotein. Overall outcomes were dismal, with a median survival of less than two months following diagnosis of the second malignancy. EBV was detected in neoplastic plasma cells in only a minority of cases, suggesting alternative pathogenetic mechanisms such as cytokine-driven B-cell activation or shared clonal origin.