Currently, the number of patients treated with immune-checkpoint inhibitor involving nivolumab is increasing. Nevertheless, it causes various immune-related adverse events (irAEs). Here, we report the case of a patient who underwent long-term follow-up after suffering from nivolumab-associated colitis. The patient was a 57-year-old man who underwent resection of a bladder tumor. Following surgery, lymph node metastasis was detected, and he was treated by nivolumab. Two months after treatment with nivolumab, the patient complained of bloody diarrhea. Colonoscopy revealed pancolitis with erosions, loss of vascular pattern and erythema. Pathological findings indicated a disease state of pan-ulcerative colitis. As an irAE by nivolumab, the patient was started with 30 mg of prednisolone. Prednisolone treatment successfully induced clinical remission and mucosal healing. Nevertheless, eight months after stopping the steroid treatment, the colitis relapsed with diarrhea following elevation of fecal immunochemical test (FIT) and fecal calprotectin (CPT). The relapsed colitis was treated by mesalazine, and then diarrhea was improved. Nivolumabassociated colitis relapsed following mucosal healing suggesting that it is necessary to consider maintenance therapy as well as remission induction for long-term survivor. The present case also demonstrates that the FIT and CPT would be effective biomarker to assess the disease activity of nivolumab-associated colitis.
Objectives
Gastrointestinal endoscopy increases the risk of bacterial exposure to endoscopists. However, before 2019, most endoscopists did not pay attention to microorganism transmission from patients. This study aimed to investigate the incidence of bacterial exposure to endoscopists’ faces during gastrointestinal endoscopic procedures using the bacterial culture method.
Methods
This was a single‐centered, retrospective study including endoscopists who performed various gastrointestinal endoscopy procedures at the Division of Endoscopy, Hirosaki University Hospital between August 31 and October 6, 2020. Endoscopists wore surgical masks and affixed pre‐sterilized films over them. Following the gastrointestinal endoscopic procedures, attached microbes were collected from the endoscopists’ surface films using sterilized swabs. Collected microorganisms were cultured on tryptic soy agar and 5% sheep blood agar, and the incidence of bacterial exposure was determined by bacterial culture positivity. Cultured bacteria were identified by gram staining and 16S rRNA gene sequencing.
Results
Bacterial culture positivity was 12.6%, and it was significantly higher in therapeutic than in diagnostic endoscopy. Notably, therapeutic endoscopy increased bacterial culture positivity in colonoscopy, but not in esophagogastroduodenoscopy. Staphylococci, including Staphylococcus epidermidis and Staphylococcus capitis, were the most commonly found bacteria in samples identified through 16S rRNA gene sequencing.
Conclusions
The risk of bacterial exposure to the endoscopist's face was increased in colonoscopy treatment procedures. Therefore, endoscopists should be aware of the significant risk of microbial infection from scattering fluid that comes from the endoscopy's working channel.
We report a case of vimentin-positive early gastric adenocarcinoma arising in a hyperplastic polyp (HP). A 72-year-old Japanese man was admitted for the detailed examination of a gastric polyp. He had a subtotal gastrectomy due to acute abdomen 12 years ago. Upper endoscopy revealed a pedunculated polyp measuring approximately 2 cm on the greater curvature of upper body of the remnant stomach. Magnifying endoscopy revealed that the microsurface pattern was irregular and partially absent accompanied with irregular microvessels at the upper end of the polyp. We speculated that the lesion was an adenocarcinoma arising in the HP. Endoscopic submucosal dissection (ESD) was performed. Histological examination of the ESD specimen revealed that the lesion consisted of well- to poorly differentiated adenocarcinoma at the protruding lesion and foveolar hyperplastic epithelia at the base of the polyp. Immunohistochemically, most of tumor cells that comprised poorly-differentiated adenocarcinoma were positive for both cytokeratin and vimentin. Although carcinomas have occasionally been found in HPs, the histological features of the present case are considered extremely unusual. To the best of our knowledge, this is the first case of vimentin-positive early gastric carcinoma arising in a HP.
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