Follicular Lymphoma: A Clinicopathological Analysis from a Tertiary Care Institute in Southern India

INTRODUCTION: Follicular lymphoma (FL) is an indolent lymphoproliferative disorder of B-cells with variable clinical behavior. It is the second most common subtype of Non-Hodgkin lymphoma in western countries but reported to have a lower incidence in Asia. MATERIALS AND METHODS: Cases of FL diagnosed in the Department of Pathology of our Institute from January 2009 to June 2015 were included in the study. The clinicopathological parameters including staging, histological details, and immunohistochemical markers CD20, CD10 and BCL-2 were recorded in all the cases. RESULTS: Of the 497 cases of Non-Hodgkin Lymphoma reported during the study period, 36 (7.2%) cases were follicular lymphoma. The mean age was 50 years with male to female ratio of 3.2:1. Grade 1/2 was seen in 70% cases. 22 % cases had low grade with high proliferation index (Ki67 > 40%). Granulomatous response was seen in two cases. Diffuse large cell lymphoma component was present in four cases. Bone marrow involvement and peripheral blood spill were seen in 12 (37.5%) and six cases (18.8%) respectively. 72% cases were in stage 3 or 4. CONCLUSION: The incidence of FL was lower in our study than other Indian studies. FL presented in the elderly, with male predominance and disseminated stage. The study highlights features of low grade with high proliferation index, granulomatous response, leukemic involvement, and transformation to high grade lymphoma.