A 68-year-old woman is evaluated after recurrent episodes of bright red blood per rectum. She has had no abdominal pain, nausea, vomiting, or hematemesis. Her medical conditions include hypertension and obesity. She is a smoker, has a sedentary lifestyle, and consumes processed food and red meat frequently. Abdominal examination shows no abnormalities. Colonoscopy reveals numerous mucosal outpouchings in the sigmoid colon, and sigmoid colectomy is performed. Histopathology of this patient's colonic lesions is most likely to reveal which of the following findings?

Question

A 68-year-old woman is evaluated after recurrent episodes of bright red blood per rectum.  She has had no abdominal pain, nausea, vomiting, or hematemesis.  Her medical conditions include hypertension and obesity.  She is a smoker, has a sedentary lifestyle, and consumes processed food and red meat frequently.  Abdominal examination shows no abnormalities.  Colonoscopy reveals numerous mucosal outpouchings in the sigmoid colon, and sigmoid colectomy is performed.  Histopathology of this patient's colonic lesions is most likely to reveal which of the following findings?

Quizplus · Accepted Answer

11ec160b_3940_292e_9249_155a48e81c50_MD0001_00 This elderly patient with hematochezia and abnormal outpouchings from the colonic lumen has diverticulosis. Diverticulosis most commonly affects the sigmoid colon and is usually seen in individuals age >60. Most patients are asymptomatic, but some may present with painless hematochezia due to disruption of the arterioles (vasa recta) adjacent to the diverticula. Diverticula can also become inflamed (ie, diverticulitis), causing left lower quadrant abdominal pain, low-grade fever, and constipation or diarrhea. Diverticula of the gastrointestinal tract may be classified according to morphology; true diverticula include all 3 layers of the gut wall and are often formed during embryologic development. False diverticula occur when the mucosa and submucosa herniate through areas of focal weakness in the muscularis. Exaggerated contractions of colonic smooth muscle segments are responsible for colonic diverticulosis; the resultant increased intraluminal pressure causes herniation and false diverticula formation. Most diverticula acquired during adult life are false (eg, Zenker diverticulum of the upper esophagus). (Choices B and E) Congenital colonic diverticulosis and Meckel diverticula are formed during embryologic development and are true diverticula containing all three layers of the gut wall. Congenital colonic diverticula are extremely rare and typically occur as a single, large diverticulum. Meckel diverticula often contain heterotopic gastric or pancreatic mucosa, and may cause bleeding, but are located in the small intestine; symptoms (ie, pain, nausea, vomiting) typically present in early childhood. (Choice C) Neoplastic mucosal growth causes colonic polyps, which are solid protuberances into the colonic lumen (rather than the outpouching away from the lumen seen in diverticulosis). (Choice D) Congenital aganglionic megacolon (Hirschsprung disease) results from the failure of neural crest cells to migrate to the colon, resulting in an aganglionic segment and severe constipation. This disease manifests in infancy with failure to pass meconium. Educational objective: Colonic diverticula often involve the sigmoid colon and develop due to exaggerated contractions of colonic smooth muscle segments. This results in increased intraluminal pressure, causing outpouching of the mucosa and submucosa through the muscularis (false diverticula). Individuals (typically age >60) may be asymptomatic or have hematochezia or diverticulitis.

A 68-Year-Old Woman Is Evaluated After Recurrent Episodes of Bright