title: Primary extra nodal non Hodgkin lymphoma: a 5 year retrospective analysis.
abstract: OBJECTIVE
  The incidence of extra nodal non Hodgkin lymphoma (ENL) is rising throughout the world. However, data regarding ENL as a group is limited. The aim was to study the epidemiological and histomorphological trends of primary ENL (pENL) in India.
  
  
  METHODS
  The biopsy materials from sixty eight patients with pENL (45 male, 23 female, M:F= 1.9:1), diagnosed over a five year period (2005-2009), were analysed and pathologically reclassified according to the World Health Organization (WHO) classification, 2008 criteria.
  
  
  RESULTS
  Primary extra nodal non Hodgkin lymphomas constituted 22.0% (68/308) of all non Hodgkin lymphomas (NHL). The mean age at presentation for pENL and primary nodal NHL was 43 years and 58 years, respectively with a male predilection (M: F=2:1). Central nervous system (CNS) constituted the most common extranodal site (20/68, 29.5%) followed by gastrointestinal tract (17/68, 25%), and nose/nasopharynx (8/68, 11.8%). Diffuse large B-cell lymphoma (DLBCL, not otherwise specified), extranodal marginal lymphoma of mucosa associated lymphoid tissue (MALT) type, and B cell NHL unclassified (U) were the three most common histological types observed. T-cell phenotype was rarely noted (4%). Follicular lymphomas and anaplastic large cell lymphoma, seen among nodal NHL, were absent at extra nodal sites. Majority (41/68, 60%) of the patients with pENL were immunocompetent and 55% were in stage I-II with favorable prognosis.
  
  
  CONCLUSIONS
  Central nervous system was the most common site of ENL, followed by gastrointestinal tract. Majority of pENL occurred in immunocompetent hosts with a favorable prognosis.
authors.affiliation: Department of Pathology, Pondicherry Institute of Medical Sciences, Ganapathychettykulam, Puducherry, India. somanath.padhi@gmail.com
authors.forename: Somanath
authors.initials: S
authors.lastname: Padhi
authors.forename: Tara Roshni
authors.initials: TR
authors.lastname: Paul
authors.forename: Sundaram
authors.initials: S
authors.lastname: Challa
authors.forename: Aruna K
authors.initials: AK
authors.lastname: Prayaga
authors.forename: Senthil
authors.initials: S
authors.lastname: Rajappa
authors.forename: D
authors.initials: D
authors.lastname: Raghunadharao
authors.forename: Rajlaxmi
authors.initials: R
authors.lastname: Sarangi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018442:Lymphoma, B-Cell, Marginal Zone / Q000145:classification / Q000401:mortality / Q000473:pathology*; D054391:Lymphoma, Extranodal NK-T-Cell / Q000145:classification / Q000401:mortality / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000145:classification / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult