December 2018 Question 1

 A 45-year-old woman presents with a 3-year history of a sense of incomplete evacuation, excessive straining to defecate, and rectal bleeding. Colonoscopy demonstrates an irregular, polypoid lesion on the anterior wall of the rectum. Biopsies reveal fibromuscular obliteration of the lamina propria and hypertrophied muscularis mucosa with extension of muscle fibers upward between the crypts.