Distribution of lymphomas in Turkey: data of 4239 cases from a single institution using the WHO classification

Background/aim: Lymphoma cases diagnosed at one of the largest tertiary reference centers in Turkey were reviewed and findings were compared to those reported from other regions of the world. Materials and methods: Lymphomas diagnosed between 2000 and 2017 in the pathology laboratory of Hacettepe University were identified. A total of 4239 cases were analyzed. The WHO 2008 classification was used. Results: Hodgkin lymphomas accounted for almost 20% of cases. T-cell lymphomas were much more frequent (23% of our non- Hodgkin lymphoma (NHL) cases) in comparison to all other regions of the world. The reason for this difference was the high frequency of mycosis fungoides (MF) cases. We had significantly more cases of high-grade B-cell lymphoma (43.9% of NHLs) and fewer cases of low-grade B-cell lymphoma (33.5% of NHLs) in comparison to the rates of developed regions of the world and the reverse was true when compared to developing parts of the world. Burkitt lymphoma frequency (4% of NHLs) was also higher than in most parts of the world. Conclusion: Our data reveal that the frequency of MF, Burkitt lymphoma, and Hodgkin lymphoma are considerably higher, whereas follicular lymphoma rates are considerably lower than in most other parts of the world.