Clinicopathological Spectrum of Indolent Small B-Cell Lymphomas: Diagnostic Challenges from a Tertiary Care Center

Introduction: Indolent small B-cell lymphomas represent a heterogeneous group of mature B-cell neoplasms characterized by overlapping clinical, morphological, and immunophenotypic features. These similarities often create diagnostic challenges, particularly in patients presenting with atypical clinical manifestations such as predominant bone marrow involvement, paraproteinemia, or unusual immunophenotypic profiles. Accurate classification is essential for appropriate prognostication and therapeutic decision-making. This study aims to evaluate the clinicopathological spectrum and diagnostic challenges associated with indolent small B-cell lymphomas in adult patients at a tertiary care center.

Methods: A retrospective observational study was conducted including adult patients diagnosed with indolent small B-cell lymphoma at a tertiary care center. Clinical presentation, hematological parameters, radiological findings, bone marrow examination, histopathological features, immunohistochemistry findings, cytogenetic analysis, and follow-up data were reviewed. Diagnoses were established according to the latest international classification systems for hematolymphoid neoplasms.

Results: Patients aged 43–70 years presented with varied clinical manifestations including anemia, peripheral neuropathy, and lymphadenopathy. Bone marrow involvement was observed in the evaluated cases. Immunophenotypic analysis demonstrated variable expression patterns among small B-cell populations, including both CD5-positive and CD5-negative profiles, with absence of Cyclin D1 and CD23 expression in selected cases. Monoclonal paraproteinemia was detected in some patients, including immunoglobulin A kappa and immunoglobulin M kappa proteins. Cytogenetic abnormalities such as deletion 13q14 and trisomy 12 were also identified. During follow-up, patients demonstrated an indolent clinical course with stable disease.

Conclusion: Indolent small B-cell lymphomas frequently demonstrate overlapping clinicopathological features that complicate definitive classification. Comprehensive integration of clinical findings, morphology, immunophenotyping, cytogenetic studies, and longitudinal follow-up is essential for accurate diagnosis and appropriate management.