A 70-year-old man comes to the office due to early satiety, nausea, and abdominal distension for the past 3 months. These symptoms have increased in frequency and limited the patient's ability to eat a full meal. For the past week, he has been unable to consume any solid food without vomiting afterward. The patient has also experienced a 13.5-kg (29.8-lb) weight loss during this period. He does not have dysphagia, hematochezia, melena, or hematemesis. Current medication is omeprazole, which he takes daily for heartburn. Temperature is 37.5 C (99.5 F), blood pressure is 132/78 mm Hg, pulse is 85/min, and respiratory rate is 12/min. Physical examination is significant for bilateral temporal wasting. Heart and lung sounds are unremarkable, and there is no appreciable lymphadenopathy. The abdomen is distended and tender to palpation in the epigastrium. A succussion splash is elicited during abdominal auscultation. Laboratory results are as follows: Which of the following most likely explains this patient's presentation?

Question

A 70-year-old man comes to the office due to early satiety, nausea, and abdominal distension for the past 3 months.  These symptoms have increased in frequency and limited the patient's ability to eat a full meal.  For the past week, he has been unable to consume any solid food without vomiting afterward.  The patient has also experienced a 13.5-kg (29.8-lb) weight loss during this period.  He does not have dysphagia, hematochezia, melena, or hematemesis.  Current medication is omeprazole, which he takes daily for heartburn.  Temperature is 37.5 C (99.5 F), blood pressure is 132/78 mm Hg, pulse is 85/min, and respiratory rate is 12/min.  Physical examination is significant for bilateral temporal wasting.  Heart and lung sounds are unremarkable, and there is no appreciable lymphadenopathy.  The abdomen is distended and tender to palpation in the epigastrium.  A succussion splash is elicited during abdominal auscultation.  Laboratory results are as follows:  Which of the following most likely explains this patient's presentation?

Quizplus · Accepted Answer

This patient with early satiety, intractable nausea and vomiting, and weight loss most likely has a gastric outlet obstruction (GOO), which results from a mechanical obstruction of the stomach or duodenum. Physical examination findings include abdominal tenderness; abdominal distension; and a succussion splash ("splash" heard on abdominal auscultation when rocking the patient back and forth at the hips), suggestive of retained food in the stomach. Hypochloremic metabolic alkalosis and hypokalemia commonly result from excessive vomiting and volume contraction. CT findings suggestive of GOO include gastric distension and air-fluid levels; however, an upper endoscopy is often needed to confirm the diagnosis. Although the etiology of GOO is broad (eg, peptic ulcer disease, bezoar, gastric polyps), up to 80% of cases occur due to malignancy, most commonly from pancreatic adenocarcinoma with gastric or duodenal invasion. The presence of unexplained hyperglycemia (ie, new-onset diabetes mellitus), particularly in a malnourished, elderly patient with bitemporal wasting, is highly suggestive of pancreatic adenocarcinoma and occurs due to islet cell destruction with tumor invasion. Pancreatic malignancy associated with GOO has a poor prognosis because the tumor is usually too advanced for surgical resection. Palliative measures include gastro-jejunal bypass and endoscopic stent placement, which allow patients to tolerate food again. (Choice A) Annular pancreas occurs when the embryonic ventral pancreatic bud fails to rotate properly around the duodenum, leading to duodenal encirclement. Most patients are asymptomatic or present early in life with GOO; in addition, it would not explain the hyperglycemia in this malnourished patient. (Choice B) A gastric bezoar results from the accumulation of undigestible materials (eg, hair, foreign objects) in the stomach. Bezoars can cause GOO but are very rare and most patients have an underlying motility disorder (eg, gastroparesis) or prior gastric surgery. (Choice C) Acute gastric volvulus can cause GOO but typically presents acutely with severe abdominal pain and hematemesis. Chronic volvulus may cause mild abdominal discomfort and nausea, but intractable nausea, vomiting, and hyperglycemia would be unexpected. (Choice E) GOO can result from large gastric or duodenal ulcers; however, proton pump inhibitors are preventative, making peptic ulcer disease unlikely. In addition, patients typically have symptoms of chronic peptic ulcer disease (eg, epigastric pain associated with eating). Educational objective: Gastric outlet obstruction presents with intractable nausea and vomiting, early satiety, and weight loss. Most cases are caused by malignancy, most commonly from pancreatic adenocarcinoma with gastric or duodenal invasion. Pancreatic adenocarcinoma can also cause unexplained hyperglycemia resulting from islet cell destruction. References: Stent placement versus surgical palliation for adults with malignant gastric outlet obstruction. (http://www.ncbi.nlm.nih.gov/pubmed/29845610) Laparoscopic gastrojejunostomy for gastric outlet obstruction in patients with unresectable hepatopancreatobiliary cancers: a personal series and systematic review of the literature. (http://www.ncbi.nlm.nih.gov/pubmed/29760541)

A 70-Year-Old Man Comes to the Office Due to Early