Gastric Area Basics for the Physician Assistant Exam
After traveling through the esophagus, your next destination in preparing for the Physician Assistant Exam (PANCE) is the lively gastric area. Containing the cardia, fundus, antrum, and pylorus, this area is just ripe for pathology and future PANCE questions. The stomach is a happening place where much of the digestion takes place. The chief cells make pepsinogen, and the paneth cells make hydrochloric acid to keep gastric pH low.
Inflammation of the stomach is referred to as gastritis. Gastritis can be classified as type A or type B:
Type A is fundal gastritis (in the fundus of the stomach), and it’s felt to be autoimmune in nature. It’s associated with inflammatory processes such as pernicious anemia.
Type B is antral gastritis. Risk factors and causes include the use of nonsteroidals (NSAIDs), Helicobacter pylori infection, alcohol use, and the use of oral steroids.
How can you search for H. pylori? It can be detected through a urea breath test. Antibodies can be detected in the blood, although the blood test isn’t the most reliable. It can be confirmed via biopsy of the affected mucosa via endoscopy. Or it can be detected in the stool via assay, which is often done after treatment to ensure that the bacteria have been eradicated.
Be familiar with the medications used for treating H. pylori gastritis. Treatment involves the use of a proton pump inhibitor like pantoprazole as well as antibiotics such as amoxicillin and clarithromycin. The duration of treatment is usually 7 to 14 days. Other medications include metronidazole and bismuth salicylate. Different medication regimens also have different eradication rates. The best eradication is the triple-threat combination of a PPI, clarithromycin, and amoxicillin.
Untreated H. pylori infections can increase the risk of developing gastric lymphoma, specifically the development of a MALToma.
Peptic ulcer disease refers to significant inflammation of the lining of the stomach (gastric ulcers) and/or the small intestine (duodenal ulcers). The ulcer forms after the lining of the stomach or duodenum breaks down.
Nothing is uglier than an ulcer, especially a gastric ulcer. The risk factors for gastric ulcers are much the same as for gastritis and can include alcohol, NSAID use, steroids, cigarette smoking, and Helicobacter pylori. Symptoms of a gastric ulcer can include pain induced by eating. If the person is bleeding from a gastric ulcer, you can see dark, tarry stools.
In a PANCE question, a gastric ulcer can present with bleeding and pain made worse with eating. A duodenal ulcer can present with pain made better with eating.
The gastric or duodenal ulcer can be diagnosed via an endoscopy. A gastric ulcer is often biopsied to differentiate a malignant gastric ulceration from a benign gastric ulcer.
The treatment for a gastric ulcer is similar to treatment for gastritis. In general, you should be aware of the H2 antagonists, proton pump inhibitors, and sucralfate:
H2 antagonists: The commonly used H2 blockers include ranitidine and famotidine. They work by inhibiting H2 secretion from the gastric parietal cells. Although H2 agonists are generally well-tolerated, a possible side effect is increased risk of sedation, especially in older people.
Proton pump inhibitors: PPIs are a very commonly prescribed class of medications. Examples include pantoprazole and esomeprazole. Because they block the secretion of hydrochloric acid from the parietal cells, they can elevate the serum gastrin levels. A common side effect of PPIs is diarrhea and altering of the bioavailability of certain supplements and medications that require a more acidic pH for absorption. They can cause hyponatremia and interstitial nephritis.
Sucralfate: Sucralfate works by forming a protective coating over the affected area. It’s usually prescribed to be taken 3 to 4 times a day. A common side effect of this medication is hypophosphatemia. It can also interact with the quinolone class of antibiotics, decreasing their absorption.
Gastric cancer is a nasty, nasty cancer with very poor long-term survival rates. Symptoms that indicate that a malignancy may be present are abdominal fullness, a decreased appetite, and type B constitutional symptoms such as fever, weight loss, and night sweats. Gastric ulcers are often biopsied in order to make sure that malignancy isn’t present.
Here are some key test points concerning gastric cancer:
Helicobacter pylori is more than a cause of gastritis and peptic ulcer disease (PUD); it’s also a leading cause of gastric cancer, which histologically is an adenocarcinoma. It can form a lymphoma. Additional risk factors for gastric cancer include smoking, drinking alcohol, and eating foods that contain a lot of nitrates.
Just to make life difficult, there are two types of gastric adenocarcinomas — intestinal type and diffuse type. On a test, if you see linitis plastica, or leather bottle stomach, think about the diffuse type of gastric cancer. (At least it’s not caused by H. pylori.)
Leser-Trélat syndrome, in which you see a bunch of seborrheic keratoses, is a sign of gastric cancer.
The diagnosis of gastric cancer is made by endoscopy and biopsy. This is the gold standard.
Treatment for gastric cancer is usually a partial or subtotal gastrectomy.
Which of the following statements concerning gastric cancer is correct?
(A) The primary treatment is chemotherapy.
(B) Paraneoplastic phenomena include acanthosis nigricans.
(C) The leading cause of gastric cancer is NSAID use.
(D) It is associated with an increased risk of inflammatory bowel disease.
(E) This type of malignancy has a low rate of metastatic spread.
The correct answer is Choice (B). Paraneoplastic phenomena associated with gastric cancer include acanthosis nigricans and Leser-Trélat syndrome. Choice (A) is wrong because gastric cancer is usually treated with surgery, primarily a partial or subtotal gastrectomy.
The leading cause of gastric malignancy is H. pylori, not NSAIDs, so you can eliminate Choice (C). There’s no direct association with inflammatory bowel disease, and at the time of diagnosis, the malignancy is usually metastatic, so Choices (D) and (E) are wrong as well.