DOI: 10.36347/sjams.2017.v05i01.042

Pages: 205-215

A substantial percentage of non-Hodgkin lymphomas (NHL) arise from tissue other than lymph nodes and even from sites which normally contain no lymphoid tissue. These forms are referred to as primary extranodal lymphomas (pENL). From January 2006 to December 2015, a total number of 1529 cases of NHL diagnosed definitely with lymphoma were included. Clinical information including demographics (age, gender) and initial site of involvement was collected. Out of 1529 cases 335 cases were of extranodal origin. This study was undertaken to ascertain the prevalence, anatomical distribution, and histological subtypes of extranodal non-Hodgkin lymphoma (NHL). This is one of the largest data from a single institution from a tertiary referral hospital in Southern India. Extranodal lymphomas constituted 335/1529 (21.9%) of all NHL. These included 209 males and 126 females (M: F= 1.65:1) and peak incidence was during the 4th to 5th decade of life. 296/335 (88.5%) of pENL had B immunophenotype whereas T cell phenotype was observed in only 39/335 patients (11.5%). GIT was the most common site of extranodal lymphomas in our study constituting 32% followed by head and neck 27.5%, CNS 8%, bone 7.5%, skin 7%, mediastinum 5%, testis 4%, soft tissue 3.8%, breast 1.49% and ovary 1%.The least common sites being kidney, urinary bladder, lung/pleura, primary liver and primary spleen. Diffuse large B-cell lymphoma, not otherwise specified (DLBCL) was the most common histological type observed in 172/286 (60%), followed by extranodal marginal zone lymphoma of MALT type 43/286 (15%). The most common histological subtype in children (age<18) was Burkitt lymphoma 20/49(41%) followed by DLBCL 10/49(20%). In adults stomach was the commonest site with DLBCL as frequent histomorphology while in paediatric population it was ileocaecum with Burkitt lymphoma.