Chapter 13: GI Stomach Neoplasms Flashcards
During endoscopy, a mass is found in a patient’s stomach. A biopsy is performed.
What is the dominent cell type?
What is the stain for?
Gastrintestinal stromal tumor of the stomach, formed by pacemaker cells of Cajal. Can be in stomach, small and large intestines, and rarely extraGI sites.
Submucosal tumor, covered by a focally ulcerated mucosa.
Microscopic examination shows spindle cells with vacuolated cytoplasms. Immunohistochemical staining for c-kit. C-KIT activation (CD117) encodes a tyrosine kinase. Give imatinib.
Relatively benign, especially in stomach.
A few mass lesions are removed from varied patients and brought to you for examination.
What are each of them?
A. Hyperplastic Polyp: Common in autoimmune metaplastic atrophic gastritis, H. pylori gastritis. Elongated, branched crypts lined by foveolar epithelium, below which pyloric or gastric glands are present. No malignant potential.
B. Tubular adenoma: True neoplasms, mostly in antrum. Most sessile and solitary. Tubular structures lined by dysplastic epithelium, may become malignant.
C. Fundic gland polyp: Contain dilated oxyntic glands lined by parietal and chief cells and by mucous cell metaplasia. Seen in patients treated with proton pump inhibitors and in familial polyposis. No risk for gastric cancer.
Risk factors for stomach carcinoma include…
Helicobacter pylori: Implicated in 2/3rds of cases. Childhood cases.
Smoking: About 50% increase in risk. Cardia most common.
Dietary factors and nitrosamines: Starch, smoked or cured fish and meat, and pickled vegetables.
Whole milk, vitamin C, and antioxidants inversely related.
Genetics: Hereditary nonpolyposis colorectal cancer (HNPCC) syndrome. DNA mismatch repair mutation.
Atrophic gastritis, autoimmune gastritis, pernicious anemia, subtotal gastrectomy, gastric adenomatous polyps.
A patient presents complaining of epigastric pain. Endoscopy reveals an ulcerating lesion, which is removed. What is it?
Ulcerating gastric carcinoma.
Edges of lesion are raised and firm. Atrophy of surrounding submucosa is seen.
Two subtypes of gastric carcinoma: Diffuse and intestinal.
An advanced gastric cancer that is a solid mass that projects into the stomach lumen.
May be partly ulcerated, deeper tissues may or may not be infiltrated.
Polypoid (fungating) adenocarcinoma
A patient presents with thickening of the stomach wall. Upon palpation, the wall is firm.
Diffuse/infiltrating adenocarcinoma.
If the entire stomach is involved, it is called a linitis plastica tumor. Invading cancer cells induce extensive fibrosis in submucosa and muscularis.
Microscopy is done on an unusual stomach mass. What are the cells with nuclei displaced by mucin ont he left image?
On the right, cells are stained with mucin.
Infiltrating gastric carcinoma.
Signet ring cells. If mucin is so prominent that extracellular cells seem to float in a gelatinous matrix, called a mucinous (colloid) carcinoma.
You have taken a biopsy of a patient with gastric cancer in order to type the appearance of his cancer.
You see this by microscopy.
Early gastric cancer (based on depth of invasion).
Type I: Projects into lumen as a polypoid or nodular mass
Type II: Superficial, flat lesion that may be slightly elevated or depressed
Type III: Excavated malignant tumor, generally represents ulceration of type I or II.
How to most gastric cancers spread?
What are some classic presentations of metastatic spread?
Metastasize mainly via lymphatics to regional lymph nodes of lesser and greater curvature, porta hepatis, and subpyloric region.
Enlarged supraclavicular node: Virchow node
Ovarian spread: Krukenberg tumor
What are some clinical features of gastric cancer?
Weight loss, anorexia, nausea. Epigastric or back pain (mimics benign gastric ulcer). Antacids or H2-receptor antagonists provide little relief. Gastric outlet obstruction, bleeding, dysphagia, achlasia.
A patient with a history of autoimmine gastritis presents with carcinoid syndrome.
Gastric neuroendocrine (carcinoid) tumor.
Derive from hyperplastic neuroendocrine cells in proximal stomach (ECL cells) in response to hypergastrinemia that follows loss of parietal cells.
A patient presents with nausea, delayed gastric emptying, and weight loss. He eats tons of persimmons and swallows unchewed bubble gum.
A mass is found in the stomach containing vegetable or fruit fibers. A bleeding gastric ulcer is also discovered.
Phytobezoar - a foreign body made of food.
Give chemical attack with cellulase, endoscopic manual disruption with jets of water. Surgery generally required for persimmon bezoars.
A nervous young girl presents with nausea and somach pain. A large foreign body is found in the stomach and is removed.
Trichobezoar: A mass hairball within a gelatinous matrix. Long-haired girls or young womenw ho eat their own hair.
