The Gastrointestinal Tract Flashcards
Complication of long-standing GERD; characterized by intestinal metaplasia within the esophageal squamous mucosa; increased risk of esophageal adenocarcinoma.
Barrett esophagus
Esophageal carcinoma associated with chronic GERD; usually occurs in the distal third of the esophagus; histologically characterized by gland formation and mucin production; premalignant lesion is Barrett esophagus.
Adenocarcinoma
More common of the histologicpatterns of esophageal cancer; associated with smoking, alcohol, caustic injury, and frequent consumption of very hot beverages; usually occurs in the middle third of the esophagus; premalignant lesion is squamous dysplasia.
Squamous cell carcinoma
Most common form of chronic gastritis; most common cause of multifocal atrophic gastritis; characterized by the following: predominantly antral, neutrophilic infiltrate with subepithelial plasma cells, serum gastrin normal to decreased; associated with hyperplastic/inflammatory polyps; (+) for H. pylori antibodies; sequelae includes gastric lymphoma.
H. pylori gastritis
Most common form of gastritis in patients without H. pylori infection; most common cause of diffuse atrophic gastritis; characterized by the following: predominantly at the body, lymphocytic infiltrate with macrophages, serum gastrin increased; associated with neuroendocrine hyperplasia; (+) for antibodies against parietal cells (proton pump and intrinsic factor); clinically, patients present with achlorhydia (due to destruction of parietal cells), and megaloblastic anemia (due to Vitamin B12 deficiency).
Autoimmune gastritis
Most common form of PUD.
Antral or duodenal (H. pylori)
Histologic findings in PUD.
NIGS: N: necrosis, I: acute inflammation, G: granulation tissue, S: fibrous scar (from superficial to deep)
Most common gastric polyp.
Inflammatory/ Hyperplastic (75%)
The most common malignancy of the stomach (90%); has two types: intestinal (bulky tumors with gland-like structures histologically); and diffuse (intense desmoplasia leading to leather bottle stomach (linitis plastic) with signet ring cells containing mucin histologically. (Lauren classification of intestinal and diffuse is used); most common site: Antrum, on the lesser curvature.
Gastric adenocarcinoma
Malignancy associated with H. pylori infection; most common site of occurrence is the stomach; eradication of H. pylori leads to tumor regression, except when it transforms to DLBCL.
Lymphoma/MALToma
Tumors of neuroendocrine origin; common site is small intestine; may elaborate hormones that can lead to ZES (gastrin) or carcinoid syndrome (serotonin); most important prognostic factor is location i.e. midgut tumors are often multiple and aggressive; immunostains: Synaptophysin and Chromogranin A.
Carcinoid
Most common mesenchymal tumor of the abdomen; more than half of cases occur in the stomach; cytogenetic origin is interstitial cells of Cajal (ICC); histologically composed of elongated spindle cells or plump epithelioid cells; Immunostains: KIT.
Gastrointestinal stromal tumor (GIST)
Most common cause of intestinal obstruction.
Hernias
Most common cause of intestinal obstruction in children <2 years old.
Intussusception
Inflammatory bowel disease characterized by the following: continuous lesions usually limited up to submucosa, with rectal involvement but disease is limited to the colon only; associated with toxic megacolon and development of colonic adenocarcinoma.
Ulcerative colitis
Most common site of diverticular disease.
Sigmoid (in areas penetrated by blood vessels)
Type of diverticulum in sigmoid .diverticulosis.
False diverticulum
Polyps common in the left colon; characterized by serrated architecture limited to the upper third of the crypt; no cytologic atypia and lateral growth; do not have malignant potential.
Hyperplastic polyp
Polyps common in the right colon; characterized by serrated architecture throughout the whole length of the gland; no cytologic atypia but exhibits lateral growth (elephant-feet glands); has malignant potential like conventional adenomas.
Sessile serrated adenoma
Autosomal dominant syndrome of hamartomatous polyps and mucocutaneous hyperpigmentation, associated with increased risk of visceral malignancies; histologically characterized by arborizing networks composed of smooth muscle intermixed with lamina propria.
Peutz-Jeghers syndrome
Morphologic variants of colonic adenomas.
Tubular, Tubulovillous, Villous
The single most important characteristic of adenomas that correlates with malignancy.
Size (>4cm) (others: architecture (villous), and severity of dysplasia
Familial syndrome characterized by early onset development of numerous colonic polyps; main pathology is mutations on the APC gene (Ch5); criterion is the presence of at least 100 polyps.
Familial adenomatous polyposis (FAP)
Familial syndrome characterized by early development of colon cancer and other visceral malignancies; main pathology is mutations in genes of DNA repair (MSH2 or MLH1) that leads to microsatellite instability and subsequent development of colonic adenocarcinoma.
Hereditary nonpolyposis colon cancer (HNPCC)/Lynch syndrome
Most common malignancy of the gastrointestinal tract; two pathways are recognized; the adenoma carcinoma sequence involving APC among others; and the microsatellite instability pathway (sessile serrated adenoma-carcinoma sequence) involving MSH2 or MLH1; clinically characterized by different symptomatologies depending on location: (Right colon: usually anemia from bleeding from the bulky nonobstructive masses; Left colon: usually presents with change in bowel habits due to napkin-ring configuration of the lesion).
Colonic adenocarcinoma
Two important prognostic factors in colonic adenocarcinoma.
Invasion and lymph node status
Most common site of metastases of colonic adenocarcinoma.
Liver
The most common cause of acute appendicitis in children and adults, respectively.
Lymphoid hyperplasia and Fecalith, respectively
The most common tumor of the appendix.
Carcinoid
