Primary extranodal non-Hodgkin lymphoma: A 3-year record-based descriptive study from a tertiary care center in...

Primary extranodal lymphoma (pENL) refers to group of disorders arising from tissues other than lymph nodes and even from sites, which normally do not contain lymphoid tissue. This study was undertaken to ascertain the prevalence, anatomical distribution, and histological subtypes of extranodal non-Hodgkin lymphoma (NHL) from a tertiary care institute in Southern India.

This was a cross-sectional study conducted in the Department of Pathology over a period of 3-years. Detailed clinical history, routine complete blood count, microbiological status was obtained from the medical records. Hamatoxylin and eosin slides were reviewed and immunohistochemistry was performed using a panel of antibodies depending on the morphology. All cases were classified based upon morphologic and immunophenotypic criteria according to World Health Organization 2008 classification.

Primary extranodal NHL constituting 22.6% (68/300) of all NHL and the majority of patients were from higher age group with peak incidence seen in fourth to fifth decade of life. In the pediatric population, the most common site is ileo-caecal region (42.8%) and the most common morphology is lymphoblastic lymphoma (42.8%). Similarly in the adult population head and neck was the most common site constituting 36% and diffuse large B-cell lymphoma is the most common morphological subtype comprising 54% of all extranodal lymphomas.

Although the reported incidence of pENL is low in India compared to other parts of the world, the possibility of pENL should always be kept in mind even though it arises in an extranodal site.