Subtype distribution of lymphomas in South of Iran, analysis of 1085 cases based on World Health Organization classification.

Lymphoma is one of the most common malignancies worldwide. Subtype distribution is different throughout the world. Some reports from the Middle East are in record. This article is trying to report the subtype distribution of lymphoma in Iran and compare it to that of Western, Far East Asian and Middle Eastern countries. A retrospective study was done on all lymphomas diagnosed in a large referral center in the South of Iran during a time period between 2009 and 2014. All diagnoses have been made according to 2008 WHO classification. A total number of 1085 cases with diagnoses of lymphoma retrieved. Twenty-nine cases (2.6 % of all) were precursor lymphoid neoplasm, 608 cases (56 % of all) were mature B cell neoplasm, 115 cases (10.5 % of all) were mature T and NK cell neoplasm, and 333 cases (30.6 % of all) were Hodgkin lymphoma. The six most frequent subtypes of mature B cell neoplasm were diffuse large B cell lymphoma, NOS (57 %), Burkitt lymphoma (7 %), small lymphocytic lymphoma (6.9 %), mantle cell lymphoma (5.7 %), extranodal marginal zone B cell lymphoma (5.2 %) and follicular lymphoma (3.6 %). Among mature T and NK cell neoplasm, mycosis fungoides was the most common type (43.4 %) followed by peripheral T cell lymphoma, NOS (20 %) and angioimmunoblastic T cell lymphoma (9.9 %). Of Hodgkin lymphoma cases, 90.6 % were classical type and 9.3 % were nodular lymphocyte predominant Hodgkin lymphoma. Extranodal involvement was seen in 42.2 % and GI tract was the most common site. Lymphoma frequencies were similar to that of Middle Eastern countries except for lower rate of follicular lymphoma and higher incidence of diffuse large B cell lymphoma, NOS and small lymphocytic lymphoma.