Frequency of Extranodal Lymphoma and their Immunophenotyping at Hamadan University of Medical Sciences Hospitals in 1385-1392

Objective: Lymphoma is one of the most common malignancies worldwide and its subtype distribution appears to differ by geographical region. Extranodal lymphomas constitute 25-40% of all lymphomas. The incidence of extranodal lymphoma is rising throughout the world more rapidly than nodal disease, especially in Middle East countries in last two decades. It seems that comparison of prevalence, subtypes and risk factors in various countries is a new clue to find definite etiology, treatment or screening modalities in future. Material and method: This retrospective study includes all cases of extranodal lymphomas during an eight year period in Hamadan province. Data of 116 patients with proved diagnosis of extranodal lymphoma, by clinical, paraclinical, morphologic and primary immunohistochemistry (IHC) results, was collected. Then appropriate IHC profile was done to reclassify according to World Health Organization classification, 2008 criteria and were analyzed with SPSS 16. Results: The mean age at presentation was 49 years and male to female ratio was 1.2: 1 (male: 63(54%), female: 53(46%)). Skin (39 cases(34%)) followed by gastrointestinal tract (34 cases(30%)) were the two most common extranodal sites. 3.5% (4 cases) were precursor lymphoid neoplasm, 61% (71 cases) were mature B cell neoplasm, 33% (38 cases) were mature T cell neoplasm and 2.5% (3 cases) were Hodgkin s lymphoma. Among non-Hodgkin s lymphomas, B cell to T cell ratio was 1.75: 1. Diffuse Large B Cell Lymphoma (DLBCL) (37%) followed by Mycosis Fungoides (MF) (33%) were the two most common immunophenotypes. Other subtypes included MALToma (extranodal marginal zone lymphoma of mucosa associated lymphoid tissue) 19%, Burkitt lymphoma (4.3%), lymphoblastic lymphoma (3.4%), Hodgkin s lymphoma, nodular sclerosis (2.6%) and Follicularlymphoma (0.9%). Two patients had two extranodal organs involved by lymphoma simultaneously. Conclusions: The mean age, sex ratio, high incidence of DLBCL and low incidence of follicular lymphoma are similar to other studies in Iran and Middle East countries, but so different from western countries. High frequency of skin involvement byMycosis Fungoides (MF) is noted in this study followed by gastrointestinal tract. Also Mantle Cell Lymphoma, Small Lymphocytic Lymphoma and Immunoproliferative Small Intestinal Disease (IPSID) were absent in this study.

کلیدواژه ها:

Lymphoma ، Extranodal ، Immunophenotype ، Immunohistochemistry