Gastrointestinal

Question 1

Drooling
Choking
Vomiting with first feed
Cyanosis (laryngospasm)
Air in stomach on XR
Failure to pass NG tube

Answer 1

ESOPHAGEAL ATRESIA WITH DISTAL TEF

Note - CXR shows gasless abdomen in pure EA

Question 2

Mechanism of jejunal and ileal atresia - “apple peel” sign on XR

Answer 2

Disruption of mesenteric vessels leading to ischemic necrosis

Question 3

Nonbilious projectile vomiting (2-6 wks)
Palpable olive
Visible epigastric peristaltic waves
Hypokalemic hypochloremic metabolic alkalosis

Associated with Macrolide use

Answer 3

HYPERTROPHIC PYLORIC STENOSIS

Treat with pyloromyotomy

Note - Bilious emesis occurs if occlusion is past 2nd part of duodenum

Question 4

Two causes of early bilious vomiting and double bubble sign on XR

Answer 4

Duodenal atresia (recanalization defect)
Annular pancreas (ventral bud)

Question 5

Embryologic origin of spleen

Answer 5

Mesentery (mesodermal)

Question 6

Retroperitoneal structures

“SAD PUCKER”

Answer 6

Suprarenal glands
Aorta and IVC
Duodenum
Pancreas
Ureters
Colon (ascending and descending)
Kidneys
Esophagus
Rectum

Note - First part of duodenum and tail of pancreas are peritoneal

Question 7

Contents of hepatoduodenal ligament

Note - Target of the Pringle maneuver

Answer 7

Portal triad:
Proper hepatic artery
Hepatic vein
Bile duct

Question 8

Contents of gastrohepatic ligament

Note - Cut to access lesser sack

Answer 8

Gastric vessels

Note - Gastrohepatic and Hepatoduodenal ligaments form the lesser omentum

Question 9

Contents of…
Gastrocolic
Gastrosplenic
Splenorenal

Answer 9

Gastroepiploic arteries
Short gastrics
Splenic artery and vein

Question 10

Layers of gut wall (4)

Answer 10

Mucosa (epithelium, lamina propria, muscularis mucosa)
Submucosa (Meissner plexus, connective tissue)
Muscularis externa (Auerbach/Myenteric plexus)
Serosa (intraperitoneal)/Adventitia (extraperitoneal)

Note - Ulcers to submucosa, erosions to mucosa

Question 11

Fastest and slowest basal electrical rhythms of GI tract

Answer 11

Fastest = Duodenum
Slowest = Stomach

Question 12

Histology of esophagus

Answer 12

Nonkeratinized stratified squamous epithelium

Question 13

Duodenal glands secreting HCO3-

Answer 13

Brunner glands

Note - May become hypertrophied with duodenal ulcers

Question 14

GI glands enterocytes, goblet cells, Paneth cells, and stem cells

Answer 14

Crypts of Lieberkuhn

Note - Goblet cell number increases as you approach rectum

Question 15

Location of Peyer’s patches (GALT)

Answer 15

Lamina propria of Ileum

Question 16

Location of plicae circulares - protrusions of villi

Answer 16

Jejunum

Proximal ileum

Question 17

Dieting/underweight patient with postprandial pain due to intermittent intestinal obstruction

Answer 17

SUPERIOR MESENTERIC SYNDROME

Transverse (3rd) portion of duodenum compressed between SMA/aorta

Question 18

Blood supply and parasympathetic innervation to…
Foregut (T12/L1)
Midgut (L1)
Hindgut (L3)

Answer 18

Celiac/Vagus
SMA/Vagus
IMA/Pelvic

Note - Foregut includes lower esophagus, stomach, proximal duodenum, liver, gallbladder, pancreas, and spleen

Question 19

Branches of common hepatic artery

Answer 19

Proper hepatic artery
Right gastric
Gastroduodenal (supraduodenal, superior pancreaticoduodenal, right gastroepiploic)

Question 20

Portosystemic anastomoses at..
Esophagus
Umbilicus
Rectum

Answer 20

L gastric-Azygous
Paraumbilical-Epigastric
Superior rectal (IMA)-Middle/Inferior rectal (internal pudendal)

Question 21

Lymphatic drainage above and below the pectinate line

Answer 21

Above…
Inferior mesenteric (superior rectal)
Internal iliac nodes (middle rectal)

Below
Inguinal nodes

Note - Superficial inguinal nodes drain most of the cutaneous lymph from the umbilicus down

Question 22

Orientation of hepatocytes in liver

Answer 22

Apical surface faces bile canaliculi

Basolateral surface faces sinusoids (fenestrated endothelium) draining to central vein

Question 23

Location and function of Kupffer cells and Stellate (Ito) cells

Answer 23

Kupffer cells = Sinusoidal, macrophages

Stellate (Ito) cells = Space of Disse between hepatocytes and sinusoids, store Vit A (quiescent) and produce ECM (activated)

Note - Bridging fibrosis in cirrhosis via Stellate cells

Question 24

Zone of liver affected earliest by viral hepatitis and ingested toxins

Answer 24

ZONE I

Zone near portal triad - blood flows away and bile flows towards

Question 25

Zone of liver affected earliest by... Ischemia Metabolic toxins Alcoholic hepatitis Note - Contains Cytochrome P-450 which is involved in damage by metabolic toxins (e.g. CCl4 oxidative damage)

Answer 25

ZONE III Zone near central vein - farthest from portal triad Note - Zone II affected by yellow fever

Question 26

Causes (2) of double-duct sign

Answer 26

Choledocolithasis (cholangitis, pancreatitis) Ductal adenocarcinoma in head of pancreas (painless jaundice)

Question 27

Path of inguinal canal

Answer 27

Spermatic cord through transversalis fascia Through deep ring (transversus abdominis) Through internal oblique Through superficial ring (external oblique aponeurosis) Into scrotum Note - Internal spermatic fascia from transversalis fascia, cremasteric muscle from internal oblique, and external spermatic fascia from external oblique aponeurosis

Question 28

Mechanism of indirect inguinal hernia Note - Lateral to inferior epigastrics

Answer 28

Failure of processus vaginalis to close (can form hydrocele) Note - Path follows descent of testes and covered by all 3 layers of spermatic fascia

Question 29

Mechanism of direct inguinal hernia Note - Medial to inferior epigastrics

Answer 29

``` Protrudes through transversalis fascia of Hesselbach triangle... Inferior epigastric (superior) Inguinal ligament (inferior) Rectus abdominus (medial) ``` Note - Path is through superficial ring and only contains external spermatic fascia from external oblique aponeurosis

Question 30

Most common hernia to incarcerate (non-reducible) and strangulate (ischemia)

Answer 30

FEMORAL HERNIAS More common in women - Occurs just lateral to pubic tubercle (medial to femoral vein)

Question 31

Action and regulation of Parietal cells (under epithelium, pink oxyntic glands) - located in body

Answer 31

GASTRIC ACID Increased - Histamine, Ach (vagal M3), Gastrin Decreased - Somatostatin, Secretin, GIP, Prostaglandin Also produces IF which binds Vit B12 for absorption in terminal ileum Note - Autoimmune destruction of parietal cells results in chronic gastritis and pernicious anemia Note - Atropine blocks vagal Ach (cephalic phase) stimulation of M3 receptor

Question 32

Action and regulation of Chief cells (deep, basophilic oxyntic glands) - located in body

Answer 32

PEPSIN PROTEASE Increased - Vagal stimulation Note - HCl required for conversion of pepsinogen to pepsin

Question 33

Action and regulation of G cells - located in antrum and duodenum

Answer 33

GASTRIN Enters systemic circulation... Increases Histamine/Parietal HCl secretion Growth of gastric mucosa Gastric motility Increased - Distention, Alkalinization, GRP (vagal), Protein Decreased - pH < 1.5 Note - Also increased by chronic PPI use, H. pylori (chronic atrophic gastritis), and Zollinger-Ellison gastrinoma

Question 34

Action and regulation of Brunner cells (in submucosa of duodenum)

Answer 34

BICARBONATE Increased - Secretin ( S cells in crypts of lieberkuhn, pancreas then prompted to make bicarb rich fluid )

Question 35

Action and regulation of D cells - located in atrum, pancreatic islets

Answer 35

SOMATOSTATIN Decreases all gastrointestinal hormones, pancreatic secretions, gastric emptying, and insulin/glucagon release Increased - Gastric acid Decreased - Vagal stimulation Note - Octreotide is a synthetic somatostatin

Question 36

Action and regulation of I cells - located in duodenum, jejunum

Answer 36

CHOLECYSTOKININ Increases pancreatic enzyme and HCO3 secretion Increases gallbladder contraction Relaxes sphincter of oddi Decreases gastric emptying Increased - Fatty acids, Amino acid Note - Acts on muscarinic pathways in pancreas

Question 37

Action and regulation of S cells - located in duodenum

Answer 37

SECRETIN Increases pancreatic HCO3 secretion Increases bile secretion Decreases gastric acid secretion Increased - Fatty acids, Gastric acid in duodenum Note - Required for functioning of pancreatic enzymes

Question 38

Action and regulation of K cells - located in duodenum, jejunum

Answer 38

GLUCOSE-DEPENDENT INSULINOTROPIC PEPTIDE (GIP) Decreases gastric acid secretion Increases insulin release (increased beta sensitivity) Increased - Fatty acids, Amino acids, Glucose (oral) Note - With GLP-1 (incretins) responsible for increased insulin release with oral glucose compared to IV glucose

Question 39

Action and regulation of Motilin - secreted in small intestine

Answer 39

Produces migrating motor complexes Increased - Fasting state Note - Acted on by Erythromycin

Question 40

Action and regulation of vasoactive intestinal polypeptide (VIP) Note - Secreted in parasympathetic ganglia in sphincters, gallbladder, and small intestine

Answer 40

Increased pancreatic HCO3 and Cl secretion Increases water and electrolyte secretion Relaxes intestinal smooth muscle and sphincters Inhibits Gastrin action on parietal cells Increased - Distension, Vagal stimulation Decreased - Adrenergic stimulation

Question 41

Watery secretory diarrhea Hypokalemia Achlorhydria Note - Persists with fasting

Answer 41

VIPoma Pancreatic islet tumor (non-a, non-b) Treat with Octreotide

Question 42

Action and regulation of Ghrelin - secreted in stomach

Answer 42

Increases appetite Increased - Fasting Decreased - Food Note - Increased in Prader-Willi

Question 43

Action of ECL cells - located in systemic circulation

Answer 43

Produce Histamine to increase parietal cell HCl secretion - Direct Gastrin action on parietal cells is minimal

Question 44

Cl and HCO3 concentration in pancreatic secretions relative to flow rate

Answer 44

High flow = High HCO3 | Low flow = High Cl

Question 45

Mechanism of zymogen activation in pancreatic secretions

Answer 45

Enterokinase/enteropeptidase on brush-border cells (duodenum, jejunum) converts Trypsinogen to Trypsin Trypsin activates other proteases (Chymotrypsin, Elastase, Carboxypeptidase) and also more Trypsin (positive feedback) Note - SPINK1 and Trypsin also inactivate Trypsin to prevent inappropriate cascading

Question 46

Intestinal channels responsible for glucose absorption

Answer 46

Apical: Na-dependent SGLT1 - Glucose, Galactose GLUT-5 - Fructose Basolateral: GLUT-2 - All carbohydrates Note - Na-dependent SGLT1 use secondary active transport, while all other GLUTs are carried-mediated (facilitated diffusion) Note - D-xylose absorption test distinguishes GI mucosal damage from pancreatic insufficiency

Question 47

Location of absorption of... Iron Folate B12

Answer 47

``` Duodenum Small bowel Terminal ileum (with bile) ```

Question 48

Function of Peyer patches

Answer 48

Contain M cells which sample antigens and lead to B cell stimulation - leads to plasma cell IgA secretion with protective secretory component for transfer to epithelium

Question 49

Rate limiting enzyme in bile synthesis

Answer 49

Cholesterol 7a-hydroxylase Note - Secretion into bile is the only method available for cholesterol excretion Notes - Fibrates inhibit this enzyme and thus decrease the cholesterol:bile acid ratio leading to gallstone formation

Question 50

Mechanism of bilirubin excretion

Answer 50

Splenic heme oxygenase converts Heme to Biliverdin Biliverdin reduced to indirect Bilirubin (water insoluble) Secreted from Macrophages into Blood (binds albumin) Hepatic sinusoids to space of Disse to hepatocytes UDPGT conjugates with Glucuronic acid To bile canaliculi as direct Bilirubin (water soluble) Gut bacteria convert to Urobilinogen Note - Majority is secreted as feces (brown), what is not secreted is mostly reabsorbed into the liver while a small minority is excreted into the kidney (yellow)

Question 51

Neoplasm responsible for painless mass/swelling of the parotid

Answer 51

PLEOMORPHIC ADENOMA Recurs if incompletely excised or ruptures Note - Pain indicates CN VII involvement by malignant Mucoepidermoid carcinoma

Question 52

Benign cystic tumor of parotid with germinal center

Answer 52

WARTHIN TUMOR Papillary cystadenoma lymphomatosum

Question 53

Progressive dysphagia to solids and liquids - may result in esophageal SCC

Answer 53

ACHALASIA Loss of myenteric Auerbach plexus (inhibitory ganglion cells) decreases NO producing neurons at LES and causes incomplete relaxation, and uncoordinated or absent peristalsis Note - May also be due to Chagas

Question 54

Distal esophageal pathology resulting in air surrounding the aorta on CT

Answer 54

BOERHAAVE PNEUMOMEDIASTINUM Hamman's sign (crunching) on chest auscultation Note - Mallory-Weiss tears at junction of GE (more distal)

Question 55

Mechanism of eosinophilic esophagitis

Answer 55

Atopy leads to dysphagia and food impaction - results in esophageal rings and linear furrows

Question 56

CMV vs HSV-1 esophagitis

Answer 56

``` CMV = Linear ulcers HSV-1 = Punched-out ulcers ```

Question 57

Causes of chronic cough

Answer 57

Postnasal drip GERD Asthma Note - Odynophagia and failure of previously effective therapy in GERD indicates progression to erosive esophagitis/ulcer

Question 58

Dysphagia Iron deficiency anemia Esophageal webs May result in esophageal SCC

Answer 58

PLUMMER-VINSON SYNDROME esophageal webs are mucosal folds that cause solid food dysphagia in mid to lower esophagus

Question 59

Mechanism of scleroderma esophageal dysmotility

Answer 59

Esophageal smooth muscle atrophy leading to decreased LES pressure and dysmotility - results in acid reflux (strictures, Barrett's) and dysphagia (aspiration)

Question 60

Dysphagia to solids - may progress to liquids eventually

Answer 60

ESOPHAGEAL CARCINOMA SCC (upper 2/3) - Alcohol, Smoking, Achalasia, Hot liquids, Caustic strictures Adeno (lower 1/3) - Smoking, Achalasia, Chronic GERD, Barrett's, Obesity

Question 61

Causes (3) of acute gastritis

Answer 61

Decreased PGE2 (e.g. NSAIDs) removes inhibition of parietal cells Burn induced hypovolemia results in mucosal ischemia (Curling's ulcer) Brain injury increases vagal stimulation, increasing Ach stimulation of parietal cells (Cushing ulcer)

Question 62

Mechanism and causes (2) of chronic gastritis

Answer 62

Mucosal inflammation leads to atrophy Hypochlorhydria and compensatory hypergastrinemia Eventually intestinal metaplasia/gastric cancer H. Pylori - Reduction in D cells with Antral predominant gastritis increasing duodenal ulceration Pernicious anemia - Autoantibodies to parietal cells and IF affects Body/Fundus (Antral sparing) Note - H. Pylori also causes gastric ulcers (decreased mucosal protection) and MALT lymphoma (increased immune response)

Question 63

Hypertrophic rugae Excess mucus Protein loss Parietal cell atrophy

Answer 63

MENETRIER DISEASE Gastric hyperplasia of mucosa - precancerous

Question 64

KIT+ tumor of interstitial cells of Cajal (pacemaker cells)

Answer 64

GIST Mesenchymal neoplasm with low malignancy

Question 65

Weight loss Early satiety Acanthosis nigricans Leser-Trelat (explosive seborrheic keratosis)

Answer 65

GASTRIC CANCER Most commonly adenocarcinoma - may also be lymphoma, GIST, carcinoid Note - Metastasis to lymph nodes and liver

Question 66

``` Gastric cancer associated with... H. pylori Nitrosamines (smoked foods) Smoking Achlorhydria (chronic gastritis) ```

Answer 66

INTESTINAL Lesser curvature ulcer with raised margins

Question 67

Histology of linitis plastica (diffuse) gastric cancer

Answer 67

SIGNET RINGS Mucin-filled cells with peripheral nuclei

Question 68

Involvement of left supraclavicular node from metastasis

Answer 68

VIRCHOW NODE Metastasis from gastric cancer

Question 69

Bilateral signet ring cells in ovaries

Answer 69

KRUKENBERG TUMOR Metastasis from gastric cancer

Question 70

Subcutaneous periumbilical metastasis

Answer 70

SISTER MARY JOSEPH NODULE Metastasis from gastric cancer

Question 71

Mechanism and causes of gastric/duodenal ulcers

Answer 71

Gastric - Decreased mucosal protection secondary to H. pylori or NSAIDs Duodenal - Increased acid secretion or decreased mucosal protection secondary to H. pylori or Zollinger-Ellison syndrome Note - Gastric ulcers should be biopsied to rule out malignancy, but duodenal ulcers are more often benign

Question 72

Most common location of ulcer hemorrhage and perforation

Answer 72

``` Hemorrhage = Posterior > Anterior Perforation = Anterior > Posterior ``` Note - Perforation only likely with duodenal ulcers

Question 73

Stain for fecal fat

Answer 73

Sudan stain

Question 74

Small intestine biopsy showing... Villous atrophy (blunting) Crypt hyperplasia Increased Intraepithelial lymphocytosis

Answer 74

CELIAC DISEASES HLA-DQ2/DQ8 IgA anti-tissue transglutaminase, anti-endomysial, anti-deaminated gliadin peptide Note - Avoid wheat, barley, rye

Question 75

Disease associated with dermatitis herpetiformis

Answer 75

CELIAC DISEASE Anti-epithelial transglutaminase

Question 76

Cramping and flatulence Osmotic diarrhea with acidic stool Normal biopsy

Answer 76

LACTOSE INTOLERANCE Confirm with hydrogen breath test > 20 ppm Note - Secondary lactose deficiency common after infectious (e.g. Giardia) or inflammatory (e.g. Celiac) disease

Question 77

Decreased duodenal pH (decreased HCO3) | Decreased fecal elastase

Answer 77

PANCREATIC INSUFFICIENCY Deficiency in Vit A, D, E, K, B12

Question 78

``` Histology associated with... Diarrhea Mesenteric nodes Arthralgia Neurologic abnormalities Endocarditis ```

Answer 78

WHIPPLE DISEASE Intracellular Gram+ Tropheryma whipplei PAS+ foamy macrophages in interstitial lamina propria

Question 79

Diseases appearing with... ``` Cobblestone mucosa Creeping fat Bowel wall thickening ("string sign") that can result in bowel obstruction Linear ulcers and fissures Anorectal findings (tags, fissures) ``` Continuous mucosal and submucosal inflammation including the rectum Friable mucosa with pseudopolyps Freely hanging mesentery Loss of haustra (lead pipe)

Answer 79

Crohn's - Transmural skip lesions with rectal sparing often presenting with RLQ pain and occult blood UC - Continuous mucosal and submucosal inflammation including the rectum often presenting with LLQ pain and hematochezia

Question 80

Diseases appearing with... Crypt abscesses and ulcers Bleeding No granulomas Noncaseating granulomas Lymphoid aggregates

Answer 80

UC | Crohn's

Question 81

Diseases resulting in... Fistulas (e.g. pneumaturia) Abscess Strictures/Obstruction ``` Colorectal cancer (non-polyploid, multifocal) Toxic megacolon/Perforation ```

Answer 81

Crohn's | UC

Question 82

Diseases associated with... Anterior uveitis Migratory monoarticular arthritis Erythema nodosum Ankylosing spondylitis Pyoderma gangrenosum Primary sclerosing cholangitis (p-ANCA) Aphthous ulcers Gallstones (decreased bile resorption) Calcium oxalate stones (increased oxalate absorption) Malabsorption (e.g. ADEK deficiency)

Answer 82

Both UC Crohn's Note - Crohn's more likely to result in malabsorption due to terminal ileal involvement

Question 83

Treatment of UC and Crohn's

Answer 83

``` UC: 5-ASA (Mesalamine) 6-Mercaptopurine Infliximab Colectomy ``` ``` Crohn's: Corticosteroids Azathioprine Metronidazole/Ciprofloxacin Infliximab or Adalimumab (anti TNF-a) ``` Note - Smoking decreases UC (but increases Crohn's)

Question 84

``` Recurrent abdominal pain Improvement with defecation Change in stool frequency Change in appearance of stool Normal biopsy ```

Answer 84

IRRITABLE BOWEL SYNDROME

Question 85

Differential for appendicitis

Answer 85

Elderly men = Diverticulitis | Women = Ectopic pregnancy (b-hCG)

Question 86

Difference between true and false diverticulum

Answer 86

True = All 3 gut layers outpouch, including muscularis externa (e.g. Meckel) False = Only mucosa and submucosa outpouch, often near vasa recta perforation of muscularis externa due to increased intraluminal pressure (e.g. constipation)

Question 87

Treatment of... Painless brisk hematochezia LLQ pain Fever

Answer 87

DIVERTICULITIS Antibiotics - If complicated (abscess, fistula, obstruction, perforation) then percutaneous drainage or surgery Note - Painless, low-volume bleeding is likely venous instead (e.g. AVM)

Question 88

``` Dysphagia Obstruction Gurgling Aspiration Halitosis Neck mass ```

Answer 88

ZENKER (FALSE) DIVERTICULUM Esophageal dysmotility results in herniation at Killian triangle at inferior pharyngeal constrictor motor abnormality of the esophagus

Question 89

Toddler with... Melana RLQ pain Associated with terminal ileal... Intussusception (red currant jelly stool) Volvulus Obstruction

Answer 89

MECKEL (TRUE) DIVERTICULUM Persistence of vitelline-duct - may contain ectopic acid-secreting gastric mucosa (Pertechnetate study+) leading to peptic ulceration (melena) heterotopic gastric mucosa or pancreatic tissue may be seen in the midst of normal intestinal mucosa Note - Related to Omphalomesenteric cyst which is a cystic dilation of the vitelline duct Note - "Rule of 2s"

Question 90

Bilious emesis Abdominal distention Failure to pass meconium Failure of internal sphincter to relax Associated with RET mutation

Answer 90

HIRSCHSPRUNG'S DISEASE Failure of neural crest cell migration - increased risk in Down's syndrome (+duodenal atresia) Aganglionic region is narrow and results in dilatation of proximal colon (rectum/anus always involved) Note - Diagnose with rectal suction biopsy

Question 91

Associated with Ladd bands - fibrous band between cecum and RLQ compressing duodenum

Answer 91

MALROTATION Failure of counterclockwise rotation Leads to midgut volvulus as narrow mesentery predisposes to twisting around SMA - omega sign on XR, bird's beak on barium enema, "corkscrew" small bowel on barium swallow Note - Sigmoid volvulus is more common in the elderly

Question 92

Lead points for intussusception

Answer 92

Meckel diverticulum Peyer patch hypertrophy (adenovirus infection) Tumor (adults) Note - Target-sign on US

Question 93

Difference between acute mesenteric ischemia, chronic mesenteric ischemia, and colonic ischemia

Answer 93

Acute mesenteric = Pain out of proportion to exam with currant jelly stool Chronic mesenteric = Postprandial bowel angina Colonic = Crampy abdominal pain followed by hematochezia in elderly or surgery patients

Question 94

Premature, formula-fed infant with... Feeding intolerance Abdominal distension Abdominal erythema May result in... Pneumatosis intestinalis Portal venous gas Free air under diaphragm

Answer 94

NECROTIZING ENTEROCOLITIS

Question 95

Polyp resulting from... Chromosomal instability pathway Mutations in APC/KRAS Note - Most sporadic cases of CRC

Answer 95

ADENOMATOUS Villous more malignant than tubular

Question 96

Polyp resulting from... CpG hypermethylation pathway Microsatellite instability/BRAF mutations

Answer 96

SERRATED "Saw-tooth" crypts on histology

Question 97

Mutation/chromosome associated with familial adenomatous polyposis Note - May also present with hepatoblastoma

Answer 97

Autosomal dominant mutation of APC tumor suppressor gene - Chromosome 5q Note - 2-hit hypothesis

Question 98

Familial adenomatous polyposis Osseous and soft tissue tumors Congenital hypertrophy of retinal pigment epithelium Impacted/supernumerary teeth

Answer 98

GARDNER SYNDROME

Question 99

Familial adenomatous polyposis | Malignant CNS tumor

Answer 99

TURCOT SYNDROME

Question 100

GI hamartomas Hyperpigmentation Increased risk of GI/breast cancer

Answer 100

PEUTZ-JEGHERS SYNDROME Autosomal dominant Hamartomas - Generally non-neoplastic solitary lesions of normal colonic tissue with distorted architecture

Question 101

Child with hamartomas throughout the GI tract - associated with increased risk of CRC

Answer 101

JUVENILE POLYPOSIS SYNDROME Autosomal dominant

Question 102

Colon cancer Endometrial cancer Ovarian cancer Skin cancer

Answer 102

LYNCH SYNDROME (HNPCC) "CEOS of Lynch inc." Autosomal dominant mutation of DNA mismatch repair genes with subsequent microsatellite instability of cell DNA (MSH2,MSH6, MLH1,PMS2)

Question 103

Difference between presentation of rectosigmoid and ascending CRC

Answer 103

Ascending: Exophytic mass Iron deficiency anemia Weight loss ``` Rectosigmoid: Infiltrating mass/encircling Partial obstruction ("apple core" on barium enema) Colicky pain Hematochezia ``` Note - IDA in males and postmenopausal women means colonoscopy! Note - Can follow with CEA but cannot diagnose with it

Question 104

Mechanism of chromosomal instability pathway for CRC

Answer 104

Loss of APC gene Decreased adhesion, increased proliferation KRAS mutation Unregulated intracellular signaling leads to adenoma Loss of tumor suppressor (p53) Carcinoma Note - In colitis associated CRC p53 mutations occur early and APC mutations late

Question 105

Causes (3) of portal hypertension

Answer 105

Cirrhosis Budd-Chiari (hepatic vein thrombosis) Schistosomiasis

Question 106

Ratio between ALT and AST in alcoholic hepatitis

Answer 106

AST/ALT > 2 Note - In non-alcoholic liver pathology ALT > AST as it is more specific to the liver

Question 107

Differentiating bone disease and biliary disease in elevated ALP

Answer 107

Elevated GGT in biliary disease Note - Often will see pale stool and dark urine

Question 108

Mechanism of thrombocytopenia in liver pathology

Answer 108

Decreased liver thrombopoietin production | Splenomegaly from portal HTN related splenomegaly

Question 109

``` Child with VZV or influenza with... Vomiting Coma Hypoglycemia Hepatomegaly Microvesicular fatty change ```

Answer 109

REYE HEPATIC ENCEPHALOPATHY ASA metabolites decreased b-oxidation in mitochondria

Question 110

Liver with... Swollen necrotic hepatocytes Neutrophilic infiltration Mallory bodies - intracytoplasmic eosinophilic inclusions of damaged keratin fibers

Answer 110

ALCOHOLIC HEPATITIS Hepatic steatosis precedes this and presents as macrovesicular fatty change - depleted NAD+ inhibits b-oxidation and inducing TG formation

Question 111

Histologic appearance of cirrhosis

Answer 111

Sclerosis around central vein Note - Irreversible

Question 112

Cellular ballooning and eventual necrosis with ALT > AST

Answer 112

NON-ALCOHOLIC FATTY LIVER DISEASE May lead to cirrhosis and HCC independent of alcohol use

Question 113

Mechanism of treatment for hepatic encephalopathy

Answer 113

Lactulose increases bacterial conversion of NH3 to NH4 trapping it in the gut Rifaximin/Neomycin decreases NH3 producing gut bacteria Note - Diuresis/TIPS (like renal failure) will impede clearance of NH3 from the blood

Question 114

``` Jaundice Ascites Anorexia Hepatomegaly (may be tender) Polycythemia (EPO production) Elevated AFP ```

Answer 114

HEPATOCELLULAR CARCINOMA Associated with HBV integration into genome Note - In cirrhosis shrunken liver instead

Question 115

Liver tumors where biopsy is contraindicated due to hemorrhage risk

Answer 115

Cavernous hemangioma: Common benign liver tumor made of cavernous blood-filled spaces Hepatic adenoma: Rare benign liver tumor associated with OCP and anabolic steroid use (generally right lobe) - appears glandular

Question 116

Malignant tumor associated with Arsenic/Vinyl Chloride exposure

Answer 116

ANGIOSARCOMA Endothelial origin

Question 117

Centrilobular congestion Grossly dark spots on tan background ("nutmeg" liver) Absent JVD

Answer 117

CONGESTIVE HEPATOPATHY (BUDD-CHIARI) Unlike cardiac cirrhosis, JVD and hepatojugular reflex are not present

Question 118

Cirrhosis with PAS+ globules in liver

Answer 118

A1AT DEFICIENCY Misfolded protein aggregates in hepatocellular ER - decreased functioning protein (elastase) in lungs leads to emphysema

Question 119

Asymptomatic or mild jaundice after fasting or stress | Indirect hyperbilirubinemia

Answer 119

GILBERT SYNDROME Autosomal Recessive mildly decreased UDPGT

Question 120

Early onset jaundice and kernicterus | Indirect hyperbilirubinemia

Answer 120

CRIGLER-NAJJAR TYPE I Autosomal Recessive absent UDPGT Note - Type II is less fatal as it responds to Phenobarbital, increasing liver enzyme synthesis

Question 121

Grossly black liver due to epinephrine metabolites that accumulate within lysosomes Conjugated hyperbilirubinemia jaundice when exposed to stressor/trigger

Answer 121

DUBIN-JOHNSON SYNDROME Autosomal Recessive defective liver excretion of bilirubin glucuronides due to mutation in canalicular membrane transport protein- benign Note - Rotor syndrome is similar but milder and without grossly black liver (also impaired uptake)

Question 122

``` Young patient with... Parkinsonism Psychiatric disease Fanconi syndrome Hemolytic anemia Cirrhosis ```

Answer 122

WILSON DISEASE (HEPATOLENTICULAR DEGENERATION) Autosomal Recessive mutation in hepatocyte copper-transporting gene (ATP7B) resulting in decreased excretion in the bile - Low serum Ceruloplasmin, elevated urinary Cu Treat with Penicillamine/Trientine chelation, oral Zinc Note - Specifically Putamen atrophy

Question 123

``` Patient > 40 y/o with... Micronodular cirrhosis Diabetes Skin pigmentation Dilated cardiomyopathy (reversible) Hypogonadism Arthropathy (calcium pyrophosphate) ``` Elevated Ferritin Elevated Iron Decreased TIBC (elevated transferrin saturation)

Answer 123

HEMOCHROMATOSIS Autosomal Recessive mutation in HFE - Decreased interaction with transferrin receptor results in increased apical enterocyte DMT1 and decreased hepatic Hepcidin production Hemosiderin (iron) identified on MRI, golden-yellow granules on biopsy, or Prussian blue stain increased risk of liver cirrhosis and HCC

Question 124

``` Intra- and extrahepatic ducts with... Onion-skin bile duct fibrosis Alternating strictures and dilation (beading) Elevated IgM p-ANCA+ ```

Answer 124

PRIMARY SCLEROSING CHOLANGITIS Can lead to secondary biliary cirrhosis - increased risk of cholangiocarcinoma and gallbladder cancer Associated with IBD Note - Other causes of secondary biliary cirrhosis include extrahepatic gallstones and pancreatic carcinoma

Question 125

``` Pruritus Cholestasis Hypercholesterolemia Destruction of intrahepatic, interlobular bile ducts Lymphocytic infiltrate Granuloma formation Elevated IgM Anti-mitochondrial antibody ```

Answer 125

PRIMARY BILIARY CIRRHOSIS ``` Associated with... Celiac sprue Sjogren Hashimoto thyroiditis CREST Rheumatic arthritis ```

Question 126

Causes (3) of gallstones

Answer 126

Increased cholesterol, bilirubin Decreased bile salts/phosphatidylcholine Gallbladder stasis Note - Risk factors are 4 F's (female, fat, forty, fertile/pregnant) Note - Also associated with Crohn's disease

Question 127

Ileus accompanied by pneumobilia

Answer 127

GALLSTONE ILEUS Fistula between gallbladder and GI tract - gallstones in intestines, air in biliary tree

Question 128

Jaundice RUQ pain Fever

Answer 128

CHARCOT TRIAD (CHOLANGITIS)

Question 129

``` Gallstone associated with... Crohn's disease Alcoholic cirrhosis Biliary infection (Ascaris, Sinensis) Chronic hemolysis TPN ```

Answer 129

PIGMENT STONES Composed of calcium and bilirubin - soft and firable ``` Black = radiopaque (hemolysis) Brown = radiolucent (infection) ``` Note - Infection releases b-glucuronidase which deconjugates bile, allowing it to bind Ca and form stones

Question 130

``` Gallstone associated with... Crohn's disease Obesity Estrogen therapy (induce HMG-CoA) Multiparity (Progesterone induced hypomobility) TPN (hypomobility) Fibrates ```

Answer 130

CHOLESTEROL STONE Radiolucent

Question 131

Diagnosis and treatment of cholecystitis Note - Pain from forcing of stone into cystic duct with CCK release

Answer 131

Diagnose with US - Wall thickening, pericholecystic fluid If equivocal, consider cholescintigraphy to assess cystic duct patency Treat with cholecystectomy only if biliary colic - Opacities in gallbladder on US may be asymptomatic

Question 132

RUQ pain Fever Murphy's sign Thickened gallbladder wall Pericholecystic fluid Distention

Answer 132

CHOLECYSTITIS Stones blocking cystic duct may not appear on US - confirm with HIDA scan Note - Emphysematous (air in wall) due to Clostridium

Question 133

Epigastric pain radiating to back Elevated serum amylase or lipase (3x upper limit) Edematous pancreas on imaging

Answer 133

ACUTE PANCREATITIS ``` Usually due to gallstones, ethanol, or trauma - may also be caused by... Hypercalcemia/Hypertriglyceridemia Drugs/ERCP Autoimmune disease Steroids Mumps Scorpion sting ```

Question 134

Fluid surrounded by granulation tissue instead of epithelium

Answer 134

PSEUDOCYST ``` Other complications of pancreatitis include... Hemorrhage Necrosis Infection Hypocalcemia ``` Note - Adipose digestion by backed up lipase leads to formation of FAs which bind Ca and precipitate as "chalk"

Question 135

Steatorrhea Vit A, D, E, K deficiency Diabetes Calcification on imaging Note - Normal amylase and lipase

Answer 135

CHRONIC PANCREATITIS Causes include alcohol and CF Note - May result in splenic vein thrombosis and fundal gastric varices

Question 136

``` Histology associated with... Smoking Abdominal pain radiating to back Weight loss Migratory thrombophlebitis Jaundice Palpable, nontender gallbladder (Courvoisier) Elevated CA 19-9 ```

Answer 136

PANCREATIC ADENOCARCINOMA Disorganized glandular structures with cellular infiltrate Note - Most occur in pancreatic head leading to obstructive jaundice

Question 137

Mechanism of increased blood pH following meals

Answer 137

ALKALINE TIDE Carbonic anhydrase used to produce H+ from H2CO3 for H/K ATPase excretion into stomach - the HCO3 is secreted into the bloodstream via HCO3/Cl antiporter

Question 138

Mechanism of hepatic encephalopathy

Answer 138

Increased NH3 in Astrocytes increases Glutamate to Glutamine conversion, resulting in Astrocyte swelling and decreased Glutamine release - decreased Glutamine in surrounding neurons decreases excitatory neurotransmission (eg. Glutamate) Increased inhibitory neurotransmission (e.g. GABA) Causes include increased protein load (e.g. Glutamine), or GI bleeding - colonic bacteria convert hemoglobin to NH3 Note - Blood urea nitrogen (BUN) decreased unlike in uremia/hypovolemia as liver cannot convert NH3 to BUN

Question 139

Interstitial edema Focal fat necrosis Calcium deposits

Answer 139

ACUTE INTERSTITIAL PANCREATITIS Eventually compromised blood flow or direct parenchymal injury causes activation of Trypsin in acinar cells - autodigestion (acute necrotic/hemorrhagic pancreatitis)

Question 140

Mechanism of cholecystitis without gallstones in a critically ill patient

Answer 140

ACALCULOUS CHOLECYSTITIS Ischemia results in inflamed and enlarged gallbladder without stones

Question 141

Microbial causes of hepatic abscess by route of transmission... Hepatic artery (hematogenous) Ascension of biliary tract (e.g. cholangitis), Direct invasion, or Portal vein pyema (adjacent sources) Penetrating injury Foodborne

Answer 141

S. aureus GNRs (E. coli, Klebsiella), Enterococci Polymicrobial E. histolytica

Question 142

Abdominal pain Acid reflux Distal (bulb) duodenal ulcers Diarrhea

Answer 142

ZOLLINGER-ELLISON SYNDROME Gastrin secreting neuroendocrine tumor (gastrinoma) in pancreas or small intestine Diagnosed with Secretin test which shows paradoxical increase in Gastrin with Secretin administration Note - Diarrhea from damage to intestinal epithelium preventing activation of pancreatic enzymes

Question 143

Gastrectomy patient with... Colicky abdominal pain Nausea Diarrhea

Answer 143

DUMPING SYNDROME

Question 144

Supplementation given to all exclusively breastfed infants

Answer 144

Vit D Iron (> 4 mos) Note - All infants also given Vit K IM after birth to prevent hemorrhagic disease of the newborn

Question 145

Poor prognostic indicators in cirrhosis

Answer 145

Elevated prothrombin time Hypoalbuminemia Hyperbilirubinemia

Question 146

Mechanism behind periumbilical and RLQ pain in appendicitis

Answer 146

Periumbilical = Visceral distention stimulates the GVA resulting in poorly localized, dull pain at T10 RLQ pain = Eventually inflammation involves the parietal peritoneum resulting in somatic pain and rebound tenderness

Question 147

Mechanism of Crohn's

Answer 147

Underexpression of NOD2 intracellular receptor in intestinal epithelium and macrophages Decreased expression of NF-kB reduces cytokine production Impaired innate immune response allows gut bacteria to produce exaggerated adaptive immune response

Question 148

Bloating Diarrhea Elevated Folate Elevated vit K

Answer 148

Small intestinal bacterial overgrowth (SIBO)

Question 149

``` Fever Firm, erythematous periauricular swelling Trismus Dysphagia Elevated Amylase Normal Lipase ``` ``` Associated with decreased salivary flow... Anticholinergics Obstruction Dehydration Post-intubation ```

Answer 149

SUPPURATIVE PAROTITIS S. aureus and Anaerobes

Question 150

Site of fat/lipid absorption

Answer 150

Jejunum Note - Without a gallbladder bile storage does not occur but is constantly released instead so fat absorption can still occur

Question 151

``` Intermittent solid/liquid dysphagia Regurgitation Chest pain Heartburn Corkscrew esophagus on barium swallow ```

Answer 151

DIFFUSE ESOPHAGEAL SPASM Impaired inhibitory neurotransmission from esophageal myenteric plexus

Question 152

Dysphagia with... Basal zone hyperplasia Elongation of lamina propria Scattered eosinophils

Answer 152

GERD May progress to Barrett's

Question 153

low maternal AFP increased nuchal translucency failed recanalization of duodenum

Answer 153

Downs syndrome related duodenal atresia on xray: double bubble sign and decreased distal intestinal gas

Question 154

serum sickness-like syndrome joint pain lymphadenopathy pruritic urticarial vasculitis rash elevated AST and ALT

Answer 154

Hep B prolonged PT time is poor prognosis

Question 155

what branch of the splenic artery is susceptible to ischemic injury after splenic artery blockage

Answer 155

short gastrics because no anastomosis left gastroepiploic has anastomosis from right gastroepiploic

Question 156

apoptotic hepatocytes form round acidophilic bodies

Answer 156

councilman bodies or apoptotic bodies acute viral hepatitis

Question 157

Abnormal sensation of a foreign body, tightness, or fullness in the throat functional disorder of the esophagus Not structural or motility disorder Anxiety related

Answer 157

Globus sensation

Question 158

``` Dysphagia Dysarthria Dysphonia impaired tongue movement impaired facial movement ```

Answer 158

Psuedobulbar palsy | related to multiple sclerosis

Question 159

``` Cutaneous flushing Hypotension Secretory Diarrhea Bronchospasm Cardiac valvular lesions ```

Answer 159

carcinoid tumor that has metastasized to the liver can also get pellagra like symptoms which may result from niacin deficiency due to depletion of tryptophan stores by carcinoid tumor as it produces excessive serotonin tx with octreotide(somatostatin analog)

Question 160

The physical manifestations of high estrogen levels in the cirrhotic patient include due to decreased metabolism of estrogen by the failing liver, decreased production of sex hormone binding globulin by the liver, and decreased metabolism of androgens

Answer 160

``` spider angiomas palmar erythema gynecomastia testicular atrophy dupuytrens contractures decreased body hair ```