Unusual biclonal IgA plasma cell myeloma with aberrant expression of high-risk immunophenotypes: first report of a new diagnostic and clinical challenge

• Main Authors: Carlos A. Monroig-Rivera (Author), Clara N. Finch Cruz (Author)
• Format: Book
• Published: Korean Society of Pathologists & the Korean Society for Cytopathology, 2023-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 2383-7837; 2383-7845; 10.4132/jptm.2023.02.07
• Keywords: biclonal iga; plasma cell myeloma; abdominal pain; high-risk phenotypes; prognosis; Pathology; RB1-214
• Source: Journal of Pathology and Translational Medicine, Vol 57, Iss 2, Pp 132-137 (2023)

IgA plasma cell myeloma (PCM) has been linked to molecular abnormalities that confer a higher risk for adverse patient outcomes. However, since IgA PCM only accounts for approximately 20% of all PCM, there are very few reports on high-risk IgA PCM. Moreover, no such reports are found on the more infrequent biclonal IgA PCM. Hence, we present a 65-year-old Puerto Rican female with acute abdominal pain, concomitant hypercalcemia, and acute renal failure. Protein electrophoresis with immunofixation found high IgA levels and detected a biclonal IgA gammopathy with kappa specificity. Histomorphologically, bone marrow showed numerous abnormal plasma cells (32%) replacing over 50% of the marrow stroma. Immunophenotyping analysis detected CD45-negative plasma cells aberrantly expressing CD33, CD43, OCT-2, and c-MYC. Chromosomal analysis revealed multiple abnormalities including the gain of chromosome 1q. Thus, we report on an unusual biclonal IgA PCM and the importance of timely diagnosing aggressive plasma cell neoplasms.