Case Report: A case of non-secretory multiple myeloma presenting with eosinophilia: diagnostic challenges and a focused literature review

hybridization (FISH) revealed 1q21 gain/amplification together with chromosome 13-related abnormalities, including RB1 deletion and D13S319 abnormality. After exclusion of secondary and primary/clonal eosinophilic disorders, the patient was diagnosed with NSMM with eosinophilia. This case highlights the diagnostic challenge posed by the coexistence of marked eosinophilia and NSMM, which obscured the underlying plasma-cell malignancy despite repeatedly negative monoclonal protein studies. We also reviewed the limited literature on MM-associated eosinophilia to underscore the importance of integrating bone marrow findings, imaging, and cytogenetic evaluation in atypical cases.