GI Flashcards
Increased level of the serotonin metabolite ___ in a 24-hour urine sample is the most useful initial test for confirming carcinoid syndrome.
5-hydroxyindoleacetic acid (5-HIAA)
Anal Squamous cell carcinoma, as well as multiple other anogenital (eg, cervical, penile, vaginal) and oropharyngeal SCCs, is strongly associated with ___ virus
human papillomavirus (HPV).
Mutations of ____ genes are associated with hereditary nonpolyposis colon cancer (ie, Lynch syndrome), an autosomal dominant disease that results in colonic, endometrial, and ovarian cancer.
DNA mismatch repair
This elderly patient with weight loss, anorexia, and iron deficiency anemia (IDA) likely has ___ cancer
colon
Colon adenocarcinoma is the most common GI cancer.
___-sided lesions = likely to bleed and cause iron deficiency anemia aka fatigue/pallor;
___-sided lesions = obstructing symptoms ( altered bowel habits, constipation, abdominal distension, N/V).
Right (ascending)
left (descending/ sigmoid)
Constipation that alternates with diarrhea is characteristic of ___ syndrome.
irritable bowel
Tenesmus (ineffectual/painful straining on defecation) and small-caliber stool are characteristic of ___ adenocarcinoma
rectal
Patient with epigastric pain, occasional melena, and left supraclavicular lymphadenopathy (ie, Virchow node) has intestinal-type ____ adenocarcinoma
gastric
*most common primary gastric malignancy.
Lesion visualized endoscopically as an ulcerated mass with irregular folded or heaped-up edges.
Glandular structures containing intestinal-like columnar (or cuboidal) cells.
Occurs with the highest incidence in patients from Eastern Asia, Eastern Europe, and South America
Due to salt-preserved foods diets
gastric adenocarcinoma
Esophageal ____ presents mostly in the proximal two-thirds of the esophagus and frequently metastasizes to the mediastinal lymph nodes.
Histology = keratin pearls and intercellular bridges
squamous cell carcinoma
Familial Adenomatous Polyposis is caused by a germline mutation to the tumor suppressor gene ______
adenomatous polyposis coli (APC)
Carcinoembryonic antigen (CEA) cannot be used to diagnose colon cancer, but it is helpful for detecting residual disease and ___.
recurrence
___ cancer is the most common cause of hepatic metastases due to direct blood flow to the liver via the portal venous circulation.
Colorectal
__ is the most important environmental risk factor for pancreatic cancer.
Smoking
____ adenocarcinoma should be considered in any patient with painless obstructive jaundice (elevated bilirubin, dark urine, pale stools) and weight loss.
Courvoisier sign (painless palpable gallbladder in a jaundiced patient) can also raise suspicion, but not specific.
Pancreatic
Hepatic ______ is associated with exposure to carcinogens such as arsenic, thorotrast, and polyvinyl chloride.
Tumor cells express CD 31, an endothelial cell marker.
angiosarcoma
Octreotide is a synthetic somatostatin analog used to control the symptoms of ___ syndrome.
carcinoid
Malignant hepatic lesions are most OFTEN from metastasis from another primary site (like ______ )
primary liver neoplasms (hepatocellular carcinoma) are much less common.
breast, lung, colon
Patient with chronic gastroesophageal reflux disease (GERD) now has dysphagia with solid foods, weight loss, and a mass in his lower esophagus, raising strong suspicion for
esophageal adenocarcinoma
Major risk factors for esophageal adenocarcinoma are:
Chronic GERD \_\_\_\_\_\_\_ Smoking Medications (nitroglycerin) Consumption of processed meats
Obesity - increases intragastric pressure, frequency of lower esophageal sphincter relaxation, and rates of hiatal hernia, which promote GERD
Carcinoid tumors are malignant transformations of ___ cells, most commonly located in the gastrointestinal tract (small intestine, rectum, APPENDIX) and the lungs
neuroendocrine
____ pattern of liver injury defined by elevated alkaline phosphatase & bilirubin
cholestatic (gallbladder obstruction)
Diphenoxylate is an opioid anti-diarrheal agent. It binds to mu opiate receptors in the gastrointestinal tract and slows __.
motility
*Overuse can lead to euphoria and physical dependence. To discourage abuse, diphenoxylate is combined with atropine, which induces adverse effects if taken in high doses.
Clostridioides difficile infection is associated with yellow-white, patchy pseudomembranes on the bowel mucosa. Contains fibrin and necrotic epithelium.
Patients may develop a nonobstructive
colonic dilation (toxic megacolon)
can lead to colonic perforation
Intraabdominal infections are polymicrobial, with ____ and E. coli being the most prominent organisms isolated
B. fragilis
Crohn disease is an inflammatory bowel disorder that causes patchy inflammation throughout the gastrointestinal tract.
(noncaseating granulomas, transmural inflammation, and Paneth cell metaplasia)
_______ are often used as first-line therapy.
Tumor necrosis factor-alpha (TNF-α), a cytokine produced by macrophages, plays a central role in the pathogenesis of CD; anti–TNF-α agents (eg, infliximab, adalimumab)
___ is a macrocyclic antibiotic (related to macrolides) that inhibits the sigma subunit of RNA polymerase, leading to protein synthesis impairment and cell death (bactericidal activity against C difficile).
Fidaxomicin
Appendicitis causes dull visceral pain at the umbilicus due to afferent pain fibers. Progressive inflammation in the appendix irritates the ____ and abdominal wall to cause more severe somatic pain shifting from the umbilicus to McBurney’s point (RLQ)
parietal peritoneum
___ , a peripherally acting µ-opioid receptor antagonist that does not cross the blood-brain barrier, can alleviate opioid-induced constipation without inducing opiate-related withdrawal symptoms.
Methylnaltrexone
This patient’s loose stools, abdominal cramps, and microcytic anemia are most likely due to ____
celiac disease
Shigella exhibits specificity for the ___ cells at the base of mucosal villi within a Peyer patch region of the ileal mucosa.
microfold (M)
A qualitative assay of stool with Sudan III stain can quickly and easily identify unabsorbed fat and confirm ____. (Stool should normally contain no measurable fat.)
malabsorption
___ disease is an inflammatory bowel disease characterized by patchy inflammation that can occur throughout the entire gastrointestinal tract.
Gross pathology demonstrates skip lesions, cobblestoning of the mucosa, bowel wall thickening, and creeping fat.
Crohn
___ is characterized by contiguous inflammation that extends from the rectum. Ulcerations are shallow and involve only the mucosa and submucosa; pseudopolyps (areas of inflamed mucosa and/or granulation tissue that appear polyp-like due to surrounding ulcerations) are seen
Ulcerative colitis
characterized by continuous inflammation of the colon limited to the mucosa and submucosa
vs
inflammation is transmural (full thickness) and segmental (skip lesions) in nature.
Ulcerative Colitis
Crohn’s
Labs can show increased breath hydrogen content, reduced stool pH, and elevated stool osmolality
Lactose Intolerance
Patients are prone to developing fistulas/abscesses as the lesions affect the entire thickness of the bowel wall. PeriANAL disease (eg, skin tags, fissures) is also common.
Chron’s
an inflammatory disease of the colonic mucosa that almost always affects the rectum and often presents with grossly bloody stool.
Ulcerative colitis
Diverticulitis is characterized by inflammation of saclike protrusions (diverticula) that typically form in the ___ colon of OLD patients.
sigmoid
Patients commonly present with constant abdominal pain, classically in the left lower quadrant, signifying sigmoid colon involvement.
Acute Diverticulitis
mild epigastric tenderness on deep palpation
Stool occult blood positive.
Hyperemic mucosa
Hyperplasia of branched, tubular submucosal glands containing alkaline secretions.
Which of the following areas is the most likely site of biopsy in this patient?
First part of duodenum
*gastric acid overproduction
