Epstein-Barr Virus-Positive Diffuse Large B-cell Lymphoma Arising in Ulcerative Colitis: An Instructive Case Report and Literature Review.

Malignant lymphoma is a relatively rare complication in patients with ulcerative colitis (UC) and its etiology is unclear. We present a hard-to-diagnose case of Epstein-Barr virus-positive diffuse large B-cell lymphoma in an elderly patient with UC who was treated with the immunomodulator tacrolimus and herbal medicine including indigo naturalis. Because malignant lymphomas can mimic other inflammatory diseases macroscopically, diagnosis in such cases can be challenging.