Pneumoperitoneum

A 56-year-old man presents to the emergency department to be evaluated for severe diffuse abdominal pain. He has associated nausea and vomiting. Past medical history is notable for four months of aching and burning epigastric pain, which worsens after eating. He has been managing the epigastric pain by taking over-the-counter antacids. At arrival, temperature is 37.9°C (100.2°F), pulse is 120/min, respirations are 22/min, and blood pressure is 120/66 mm Hg. Diffuse abdominal tenderness to palpation is noted on the physical examination. An upright abdominal radiograph is obtained and shown below. Which of the following best explains this patient’s underlying pathology?  


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