Cases

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Zenker (pharyngoesophageal) diverticulum: The frontal (see Image 1) and lateral (see Image 2) barium-swallow images of the upper esophagus demonstrate a large outpouching at the posterior aspect of the pharyngoesophageal junction that retains barium (arrows), consistent with a Zenker diverticulum. Zenker diverticulum, or pharyngoesophageal diverticulum, is a pseudodiverticulum consisting of esophageal mucosa and submucosa that herniates posteriorly between the cricopharyngeus and the inferior pharyngeal constrictor muscles through an area of potential weakness referred to as the Killian dehiscence. The pathogenesis of this condition is not well known. Patients with Zenker diverticulum are thought to have dis-coordination of the swallowing mechanism that increases pressure on the mucosa of the pharynx and that over time leads to the herniation of esophageal mucosa from the Killian dehiscence. The condition most commonly occurs in elderly women, with peak incidence in the seventh to ninth decades of life. The most common presenting feature is upper-esophageal dysphagia, which occurs in as many as 98% of patients. Other common symptoms are halitosis, regurgitation of undigested food, aspiration, noisy deglutition, and changes in voice (eg, hoarseness). Weight loss, possibly due to limited caloric intake and recurrent pulmonary infection from aspiration, occur in approximately one third of patients. In patients with Zenker diverticulum, physical findings are usually normal. Fluoroscopic barium swallow study is the mainstay of diagnosis and demonstrates the characteristic outpouching arising from the midline of the posterior wall of the distal pharynx near the pharyngoesophageal junction. The finding is best identified during swallowing and is typically seen on lateral images, on which the diverticulum is observed at C5-6 vertebral level. If the diverticulum is large, it may protrude laterally, most often to the left side. After the bolus of contrast agent passes the upper esophagus, the diverticulum is typically seen extending posterior to the cricopharyngeus muscle, and the contrast material that was retained in the diverticulum may be regurgitated into the hypopharynx. The lumen of the diverticulum should be carefully observed for irregularities or filling defects because squamous cell carcinoma can develop in a small percentage of cases. When incidentally imaged on CT or MRI, Zenker diverticulum appears as a structure that arises posteriorly from the hypopharynx and is filled with air, fluid, or oral contrast material. The Zenker diverticulum may also be found on endoscopy. Care must be taken during the procedures because passage of the endoscope into the diverticulum may result in perforation. Small, asymptomatic diverticula may be followed up by monitoring the progression of symptoms. Surgical management should be considered in patients with clinically significant dysphagia, weight loss, pulmonary aspiration with recurrent lung infections, and complications related to bleeding. Surgical options include myotomy of the cricopharyngeus muscle with or without diverticulopexy or endoscopic division of diverticular wall with stapling. The success rate, ie, the relief of symptoms as measured in most studies, is approximately 93%. For more information on Zenker diverticulum, see the eMedicine articles Zenker Diverticulum (within the Internal Medicine specialty), Zenker Diverticulum (within the Radiology specialty), and Zenker Diverticulum (within the Otolaryngology specialty).