comparative diagnostic performance of flow cytometry, aspiration, and biopsy with immunohistochemistry in plasma cell neoplasms

Background: plasma cell neoplasms (pcns) are a heterogeneous group of hematologic malignancies that require accurate and timely diagnosis for effective management. despite the availability of multiple diagnostic tools, challenges remain due to clinical and morphological variability. this study aimed to compare the diagnostic performance of three key modalities, including flow cytometry (fcm), bone marrow aspiration (bma), and bone marrow biopsy with immunohistochemistry (bmb+ihc) in patients with plasma cell neoplasms.materials and methods: a cross-sectional study was conducted on 52 patients with confirmed pcns. diagnostic outcomes from fcm, bma, and bmb+ihc were evaluated and compared. sensitivity, specificity, predictive values, and inter-method agreement were calculated using spss version 27.results: bmb+ihc achieved the highest diagnostic yield (100%), followed by bma (55.8%), while fcm demonstrated the lowest diagnostic rate (32.7%). flow cytometry showed excellent specificity and a positive predictive value of 100%, but limited sensitivity (32.7–58.6%), resulting in a high rate of false negatives. bma frequently underestimated plasma cell burden due to sampling variability and hemodilution. collectively, integration of all three methods provided complementary diagnostic value, reducing the risk of misclassification.conclusion: bone marrow biopsy with immunohistochemistry remains the gold standard for diagnosing pcns. however, combining it with aspiration and flow cytometry offers a more comprehensive diagnostic framework, improving accuracy, minimizing false negatives, and supporting optimal patient management.