Bone Marrow and Peripheral Blood Evaluation in Non-Hodgkin Lymphoma – A Cross Sectional Study of 78 Cases in a Tertiary Care Centre in Kerala

BACKGROUND In the evaluation of patients with non-Hodgkin lymphoma (NHL), determination of bone marrow involvement is an integral part of staging work up. Peripheral blood counts and examination of blood smears are also done in patients with lymphoma as part of pre-treatment investigations. METHODS A cross sectional study of 78 patients with a prior histopathological diagnosis of NHL was conducted. Peripheral blood counts were performed on an automated haematology analyser to look for various cytopenias. Peripheral blood smears and bone marrow aspirate (BMA) / imprint smears were examined in detail for atypical lymphoid cells. Bone marrow trephine biopsies of these patients were studied to assess the NHL involvement and the various patterns of involvement. Adjuvant immunohistochemistry (IHC) was performed in bone marrow biopsies with scant cellularity or crush artefact to discern the marrow involvement. RESULTS Bone marrow trephine biopsy showed involvement by lymphoma in 65.4 % cases. The incidence of involvement was higher in B-cell lymphomas, especially in low grade types. The predominant pattern of involvement was interstitial pattern (41.2 %). Discordant histology between bone marrow and the primary anatomic site was found in 7.8 % of the cases, which was seen more in diffuse large B-cell lymphomas. Majority of the patients with bone marrow infiltration by NHL had anaemia (84.3 %). Bicytopenia and pancytopenia were also observed. On peripheral blood smear examination atypical lymphoid cells were present in 23 % cases. CONCLUSIONS Bone marrow examination is an important aspect in the diagnosis of NHL, because of its both prognostic and therapeutic implications. Hence, the presence of atypical lymphoid cells and other changes in the peripheral blood should be detected in these patients. KEYWORDS Non-Hodgkin Lymphoma, Bone Marrow Biopsy, Bone Marrow Aspirate / Imprint, Peripheral Blood Smear, Atypical Lymphoid Cells