Flowcytometry aiding morphological diagnosis of mature B-cell neoplasm in patients with lymphocytosis

Abstract

Background: Mature B-cell neoplasms (MBCNs) are a category of disorders with a broad range of clinical manifestations, pathologic features, and outcomes that share common characteristics. They originate from the B-cell lineage, are clonal, and have the immunophenotypic and genetic features of mature B-cells. Flow cytometry (FC) is a widely used method for diagnosing suspected lymphoproliferative disorders in patients with lymphocytosis, lymphadenopathy, and other lymphoproliferative disorders. Aim: To evaluate the role of FC in confirming the provisional morphologic diagnosis in patients with MBCNs. Materials and Methods: This is a retrospective; descriptive study conducted on 193 adult patients newly diagnosed with MBCNs; immunophenotypic findings of the patients were reviewed. The B lymphocytes were identified according to their Side-Scattered/CD19 distribution. Results: Chronic lymphocytic leukemia (CLL) was the most common subtype (127, 65.9%). Splenomegaly was noted more frequently in hairy cell leukemia variant cases (85.7%) and hairy cell leukemia cases (75%). The anemia at presentation was the least frequent in CLL (20%). The CD5+/CD23+ phenotype of CLL was seen in 114 cases (90%); negativity for FMC7 showed high sensitivity (93.7%) and sufficient specificity (60%) in the diagnosis of CLL. Conclusions: It is difficult to diagnose B-chronic lymphoproliferative disorders solely based on morphologic findings. Consequently, FC findings combined with clinical, hematologic, and morphologic features can confidently result in a precise diagnosis.

Keywords

• chronic lymphocytic leukemia
• chronic lymphoproliferative disorders
• flow cytometry
• lymphocytosis