Subclinical Celiac Disease Unmasked by Immune Checkpoint Inhibitor Therapy.

Immune checkpoint inhibitors (ICI) are antibodies that block immune checkpoint proteins from binding with their partner proteins on cancer cells, subsequently allowing cytotoxic T-cell-associated enhancement of antitumor responses. Although ICIs have become the standard of care for various malignancies, their use is often limited by unique immune-related adverse events, including dermatologic, endocrine, inflammatory, hepatic, and gastrointestinal events. Diarrhea and colitis are common lower gastrointestinal tract immune-related adverse events, however, only a few cases have reported the association between celiac disease (CD) and ICIs. We report here a case of a 75-year-old man with new onset CD after exposure to the cytotoxic T-lymphocyte-associated antigen-4 ICI, ipilimumab. Although ICI-induced CD is relatively rare, it is essential to consider it in a genetically susceptible patient undergoing treatment with ICI. Patients with known high susceptibility to CD, such as a family history of CD, or with the ancestry of high celiac penetrance (eg, Northern Europe, North Africa, etc), dermatitis herpetiformis, or chronic bowel symptoms, we feel should have celiac panel testing before initiating ICI therapy.

Endoscopic mucosal resection and cure for rectal mucosa-associated lymphoid tissue lymphoma.

We present a case of Helicobacter pylori-negative rectal mucosa-associated lymphoid tissue (MALT) lymphoma found on colonoscopy done for colorectal cancer screening. The lesion was successfully removed with endoscopic mucosal resection alone, without concomitant antibacterial treatment. On surveillance exams, the patient has had a 5-year disease-free survival. While prior reports highlight use of multiple modalities, this is the only case we are aware of in which treatment with endoscopic mucosal resection alone without antimicrobial therapy led to disease-free survival at 5 years.