S2150 Triangle of Lymphocytic Colitis, Epstein-Barr Virus, and Lymphoma: Is There Any Association?

Abstract

Introduction: Epstein–Barr virus (EBV), is linked to range of lymphoproliferative lesions and malignant lymphomas of B-, T- and NK-cell origin. EBV-positive diffuse large B cell lymphoma (DLBCL) not otherwise specified is a variant of DLBCL seen in patients without known immunodeficiency or prior lymphoma. In few reports EBV infection was more commonly detected in colonic mucosa of patients with Microscopic Colitis (MC), but it remains unclear if this translates to higher incidence of lymphoma in this subgroup of people. Here, we describe a case of DLBCL in patient with MC associated with EBV infection in context of recent findings. Case Description/Methods: 77-year-old female with history of COPD, diabetes underwent colonoscopy for chronic diarrhea of 4-month duration. She suffered from 3-4 loose stools/day, and had normal celiac panel, fecal elastase, and infectious workup. Colonoscopy was unremarkable except for 4 mm Paris Is polyp in sigmoid colon removed with cold snare. On pathology, the random colon biopsies were positive for lymphocytic colitis along and polyp showed DLBCL (non-germinal center phenotype) along with positive EBV infection (Figure). Discussion: It is widely believed that overall risk of malignancy is not increased in MC. However, theoretically MC should increase risk of lymphoma as it is more likely to be associated with oncogenic EBV than Ulcerative colitis or irritable bowel syndrome (90 % vs 66 % vs 0 % respectively). EBV increases the risk of lymphoma due to protein expression in transformed infected lymphocytes that results in immune evasion and suppression of apoptosis. Earlier studies have shown no evidence of higher risk of lymphoma in MC, however recently Bergman et al. (2021) analyzed data from Sweden´s pathology departments and from the Swedish Cancer Register and included 11758 patients with incident MC and found an increased risk of lymphoma (adjusted HR 1.43 [1.06–1.92]). Studies are needed to explore risk of lymphoma in subgroup of MC patients with EBV infection as inflammation cause by MC and concomitant EBV infection enhance the overall malignant potential. In conclusion, MC may not be as benign entity as it was once thought to be as it is more likely to harbor oncogenic EBV virus. Even diminutive polyps in MC can potentially harbor lymphoma and should be removed and submitted for analysis rather than being discarded.Figure 1.: Colonoscopy image showing small polyp (left) and schematic (right) of triangle between CMV, microscopic colitis and lymphoma error.