Introduction: The relationship between inflammatory bowel disease (IBD) and lymphoproliferative disorders (LD) has been previously reported.
Aims: To establish the local incidence of LD in an IBD unit, and to describe the clinical characteristics of observed cases.
Material and methods: All the clinical records of patients with ulcerative colitis (UC) or Crohn's disease (CD) followed-up in a tertiary center were reviewed. In all cases, IBD had been diagnosed according to standard criteria.
Results: Of 911 patients with IBD, we identified seven with lymphoma. Five of the patients were men, four had been diagnosed with UC and three with Crohn's disease. The mean time from IBD to lymphoma diagnosis was 4.82 years (r: 0-20). The mean age at lymphoma diagnosis was 53 years (r: 33-76). Four were colorectal lymphomas. There was only one case of Hodgkin's disease. Five patients had been treated with thiopurines, and four of these had also been treated with biological agents. Three cases were associated with Epstein-Barr (EBV) virus infection. The estimated incidence of LD in these IBD patients was 81.74/100,000/year. After a mean follow-up of 32.3 months (r: 5-57) following the last treatment for LD, all patients except one are in remission.
Discussion: The incidence rate of LD was much higher than the expected rate for the general population (81.74 vs. 22). Chronic inflammation, immune-modifying drugs and Epstein Barr virus infection may be implicated in the pathogenesis of this disease.