Huiying Zhao,1,* Ling Qin,2,* Geng Wang,1 Jianying Li,1 Yuan Huang,1 Jie Niu,1 Xuzhen Qin1 

1Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, People’s Republic of China; 2Department of Infectious Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College Hospital, Beijing, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xuzhen Qin, Email qxz_01@163.com

Abstract: Waldenström macroglobulinemia (WM) is a relatively rare hematological malignancy characterized by serum monoclonal IgM gammopathy and bone marrow infiltration of lymphoma cells (small B lymphocytes, plasmacytoid lymphocytes, or plasma cells). Elevated CA125 is most seen in ovarian cancer or some benign diseases such as pelvic inflammatory disease and endometriosis. No cases of WM combined with elevated CA125 have been reported so far. Here, we report two rare cases of WM with abnormally high CA125 at the onset of illness. Patient 1 had a nine-year history of pulmonary shadow with a moderately increased CA125 level. Subsequently, she was diagnosed with WM-related lung involvement by biopsy. Patient 2 presented with WM manifestation and a significantly elevated CA125 level of unknown significance. Based on bone marrow smear results and serum IgM levels, the diagnosis of WM was established in both patients. After rigorous physical examination, imaging screening, and pathological biopsy, any underlying disease associated with elevated CA125 in both patients was excluded. CA125 and IgM levels decreased with effective treatment for WM, suggesting that abnormally elevated CA125 was related to the progression of macroglobulinemia. Suspicious WM patients with elevated serum CA125 of unknown significance need to be alert to a special manifestation of macroglobulinemia. More clinical concern is needed. At the same time, the clinician could monitor the patient’s serum CA125 level changes to assist in the judgment of the efficacy of the original disease. This report extends the understanding of WM and the application of CA125.

Keywords: macroglobulinemia, CA125, monoclonal IgM gammopathy, B-cell tumor, case report