A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 70 year-old man comes to the physician for difficulty swallowing for 6 months. During this time, he has occasionally coughed up undigested food. He did not have weight loss or fever. Four weeks ago, he had an episode of sore throat, that resolved spontaneously. He has smoked one pack of cigarettes daily for 5 years. He has gastroesophageal reflux disease and osteoporosis. Current medications include alendronate and omeprazole. His temperature is 37.0°C (98.6°F), pulse is 84/min, and blood pressure is 130/90 mmHg. On examination, he has foul-smelling breath and a fluctuant mass on the right neck. Which of the following is most likely involved in the pathogenesis of this patient's symptoms?
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A
Deep neck space infectionIncorrect. Deep neck space infection would present with acute tender neck swelling, fever, and toxicity — not chronic dysphagia and regurgitation.
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B
Degeneration of neurons in the esophageal wallIncorrect. Degeneration of myenteric neurons describes achalasia — characterized by dysphagia to both solids and liquids and esophageal dilation, not a focal cervical neck mass.
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C
Cellular dysplasiaIncorrect. Cellular dysplasia (esophageal carcinoma) usually causes progressive dysphagia and weight loss, sometimes with hematemesis — but not a fluctuant neck mass or regurgitation of long-stored food.
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D
Abnormal esophageal motor functionCorrect. Zenker diverticulum is a pulsion diverticulum caused by abnormal upper esophageal motor function (failure of cricopharyngeus relaxation), producing food trapping, halitosis, and a fluctuant neck mass.
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E
Autoimmune destruction of esophageal smooth muscleIncorrect. Autoimmune smooth muscle destruction describes scleroderma esophageal involvement (causing GERD and dysmotility), not Zenker diverticulum, which results from cricopharyngeal dysmotility producing a posterior pulsion outpouching.
↑ Tap an answer to reveal the reasoning
Answer: D. An elderly man with progressive dysphagia, regurgitation of undigested food, halitosis (foul breath), and a fluctuant lateral neck mass has a Zenker diverticulum. This is a false (pulsion) diverticulum that herniates posteriorly through Killian's triangle — the area of weakness between the thyropharyngeus and cricopharyngeus muscles of the inferior pharyngeal constrictor. The underlying pathogenesis is dysmotility: failed relaxation of the cricopharyngeus (upper esophageal sphincter) during swallowing creates increased intraluminal pressure, which then drives mucosal herniation through the weak area.
The key concept tested is that the cause is abnormal esophageal/pharyngeal motor function (specifically of the upper esophageal sphincter / cricopharyngeus). Treatment is endoscopic or surgical cricopharyngeal myotomy, often combined with diverticulectomy or diverticulopexy.
Deep neck space infection would cause acute tender neck mass with fever and signs of toxicity. Degeneration of esophageal neurons describes achalasia, which causes dysphagia to solids AND liquids and esophageal dilation, not a discrete neck mass. Cellular dysplasia (e.g., esophageal cancer) typically causes progressive dysphagia and weight loss, not a fluctuant neck mass or regurgitation of food eaten days earlier.
Clinical pearl: be cautious with blind nasogastric tube placement in suspected Zenker — risk of diverticular perforation.
**Why each option:**
**A.** Deep neck space infection would present with acute tender neck swelling, fever, and toxicity — not chronic dysphagia and regurgitation.
**B.** Degeneration of myenteric neurons describes achalasia — characterized by dysphagia to both solids and liquids and esophageal dilation, not a focal cervical neck mass.
**C.** Cellular dysplasia (esophageal carcinoma) usually causes progressive dysphagia and weight loss, sometimes with hematemesis — but not a fluctuant neck mass or regurgitation of long-stored food.
**D.** Correct. Zenker diverticulum is a pulsion diverticulum caused by abnormal upper esophageal motor function (failure of cricopharyngeus relaxation), producing food trapping, halitosis, and a fluctuant neck mass.