Rituximab-induced Ileocolitis in a Patient with Gastric MALToma: A Case Report and Literature Review

Intern Med. 2021;60(5):731-738. doi: 10.2169/internalmedicine.5119-20. Epub 2021 Mar 1.


Rituximab (RTX) is effective for treating cancer, but reports of RTX-associated enterocolitis are limited. We herein report the case of a 65-year-old man who developed RTX-induced ileocolitis. He was diagnosed with gastric mucosa-associated lymphoid tissue lymphoma (MALToma) and treated with RTX. He complained of bloody diarrhea after RTX. Mucosal inflammation on colonoscopy indicated RTX-induced ileocolitis. He was treated with corticosteroids, and his symptoms improved. We reviewed the RTX-associated gastrointestinal adverse events and classified the features into ulcerative colitis, Crohn's disease, microscopic colitis, and ileocolitis. To our knowledge, this is the first case of a Japanese patient who developed RTX-induced ileocolitis.

Keywords: B cells; MALToma; T cells; ileocolitis; inflammatory bowel disease; rituximab.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Aged
  • Colitis, Ulcerative* / chemically induced
  • Colitis, Ulcerative* / diagnosis
  • Colitis, Ulcerative* / drug therapy
  • Colonoscopy
  • Crohn Disease*
  • Humans
  • Lymphoma, B-Cell, Marginal Zone* / chemically induced
  • Lymphoma, B-Cell, Marginal Zone* / diagnosis
  • Lymphoma, B-Cell, Marginal Zone* / drug therapy
  • Male
  • Rituximab / adverse effects


  • Rituximab