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Advanced Endoscopic Techniques

Introduction: Gastrointestinal toxicity resulting in diarrhea is common in patients taking mycophenolate mofetil (MMF). The general approach is to taper the dose or switch to its enteric-coated counterpart, negating further investigation when a good response is achieved. However, when investigated, endoscopic and histological findings often overlap with other colonic disorders. After cessation of MMF, these findings should resolve over time. Uncertainties may arise as to whether biopsies are required, as most lesions will heal. We report a challenging case of a patient who presented with a healed malignant ulcer. Case Report: A 77-year-old man with a background history of heart transplant was referred for an endoscopic resection for a solitary high-grade dysplastic lesion in the hepatic flexure. This was detected incidentally while he was being investigated for ongoing diarrhea. An area of erythema on a background of colitis was visualized on index colonoscopy. The colitis was attributed to MMF. This was ceased, and his symptoms abated. A repeat colonoscopy performed 6 weeks later showed no abnormalities. After being presented with the options of a colectomy versus another colonoscopy, the patient opted for the latter. In this instance, a 9-mm, subtle, flat, and mildly erythematous lesion was detected (Fig. 1a). We were able to define and characterize the lesion better using narrow-band imaging (Fig. 1b). An endoscopic submucosal dissection was then carried out, and the lesion resected in an en bloc fashion (Fig. 1c). Histopathological evaluation showed this to be an intramucosal adenocarcinoma (Fig. 1d). Conclusion: In immunosuppressed patients, given the atypical and often subtle presentation of colon cancers, it is important to be extra vigilant and sample all ulcers, erosions, and erythematous patches. It is worthwhile to tattoo an area distally to aid in identification if the area needs to be reevaluated or resected at a later date.