Objective: To identify the clinical characteristics and tissue CD56 expression pattern in patients with multiple myeloma (MM) with bone-related extramedullary disease (b-EMD), not connected to or isolated from the bone marrow.
Methods: We reviewed consecutive patients with MM hospitalised at the First Affiliated Hospital of Fujian Medical University between 2016 and 2019. Patients with b-EMD were identified, and the clinical and laboratory features of patients with and without b-EMD were compared. Immunohistochemistry of extramedullary lesions was performed based on b-EMD histology.
Results: Ninety-one patients were included in the study. Among them, 19 (20.9%) were found to have b-EMD at initial diagnosis. Median age was 61 years (range, 42-80 years), with a female/male ratio of 6/13. The most common site of b-EMD was the paravertebral space (11/19; 57.9%). Compared to those without b-EMD, patients with b-EMD had lower levels of serum β2-microglobulin and similar levels of lactate dehydrogenase. Immunophenotype analysis based on histopathology showed that CD56 was expressed in 9/10 (90.0%) patients with b-EMD.
Conclusion: A considerable number of MM patients presented with b-EMD at the time of initial diagnosis, and most patients with b-EMD exhibited CD56 expression, highlighting a potential new therapeutic target in the future.
Keywords: CD56; bone-related extramedullary disease; multiple myeloma.
© 2023 by the Association of Clinical Scientists, Inc.