A 61-year-old man with medical comorbidities of coronary artery disease, congestive heart failure, hypertension, and dyslipidemia presented to the gastroenterology clinic for screening colonoscopy. The patient denied any gastrointestinal related complaints. Screening colonoscopy revealed good bowel preparation with a score of 8 on Boston Bowel Preparation Scale and a firm 4 mm nodule in the rectum (image attached) that was removed. Biopsy and immunohistology of the rectal nodule , positively stained for periodic acid-Schiff (PAS) staining and S-100 protein, revealed a type of tumor which is rarely found in the rectum (images attached).
What is the likely diagnosis in this case? *This case is from Docplexus Editorial Team for educative purpose only. Source: Case Reports in Gastrointestinal Medicine
