Kaplan USMLE Step 1: Patient reports difficulty swallowing liquids

If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 1 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series.

A 60-year-old man comes to the physician because of progressive difficulty swallowing. Initially, his dysphagia was limited to solids but he now has difficulty with swallowing liquids. Endoscopy shows a large, fungating mass two cm above the gastroesophageal junction. The mass is biopsied, and microscopic examination of the specimen shows glands that invade into the muscular layer and cells with large, hyperchromatic nuclei. Which of the following is most likely directly associated with the development of this mass?

A. Esophageal rings

B. Esophageal webs

C. Reflux esophagitis 

D. Scleroderma

E. Sliding hiatal hernia

The correct answer is C.

Chronic reflux esophagitis in the lower esophagus can lead to Barrett esophagus, in which normal squamous epithelium in the distal esophagus is replaced by metaplastic intestinal (glandular) columnar cells. This increases the risk for adenocarcinoma, which can presents with solid-food dysphagia progressing to liquids.

Choice A. Chronic reflux esophagitis and Barrett esophagus are major risk factors for the development of esophageal adenocarcinoma, which is the most likely diagnosis in this patient. Esophageal rings are concentric protrusions of mucosa in the lower esophagus that are not directly associated with adenocarcinoma.