Gastrointestinal Flashcards
1
Q
GI embryo - foregut, midgut, hindgut
A
Foregut - pharynx to duodenum
Midgut - duodenum to proximal 2/3 of transverse colon
Hindgut - distal 1/3 of transverse colon to anal canal above pectinate line
2
Q
Developmental defects of anterior abdominal wall due to failure of:
A
Rostral fold closure - sternal defects
Lateral fold closure - omphalocele, gastroschisis
Caudal fold closure - bladder exstrophy
3
Q
Duodenal atresia
A
Failure to recanalize (trisomy 21)
4
Q
Jejunal, ileal, colonic atresia
A
Due to vascular accident (apple peel atresia)
5
Q
Midgut development
A
6th week - midgut herniates through umbilical ring
10th week - returns to abdominal cavity + rotates around superior mesenteric artery (SMA)
6
Q
Gastroschisis
A
extrusion of abdominal contents through abdominal folds; not covered by peritoneum
7
Q
Omphalocele
A
Persistence of herniation of abdominal contents into umbilical cord, sealed by peritoneum
8
Q
Tracheoesophageal anomalies
A
Esophageal atresia (EA) with distal tracheoesophageal fistula (TEF) is the most common (85%)
Results in drooling, choking, and vomiting with first feeding. TEF allows air to enter stomach (visible on CXR). Cyanosis is secondary to laryngospasm (to avoid reflux-related aspiration). Clinical test: failure to pass nasogastric tube into stomach
In H-type, the fistula resembles the letter H. In pure EA the CXR shows gasless abdomen
9
Q
Congenital pyloric stenosis
A
Hypertrophy of the pylorus causes obstruction. Palpable “olive” mass in epigastric region and nonbilious projectile vomiting at about 2-6 weeks old. Occurs in 1/600 live births, more often in firstborn males.
Results in hypokalemic hypochloremic metabolic alkalosis (secondary to vomiting of gastric acid and subsequent volume contraction). Treatment is surgical incision (pyloromyotomy)
10
Q
Pancreas and spleen embryo
A
Pancreas - derived from foregut. Ventral pancreatic buds contribute to uncinate process and main pancreatic duct. The dorsal pancreatic bud alone becomes the body, tail, isthmus, and accessory pancreatic duct. Both the ventral and dorsal buds contribute to the pancreatic head.
Annular pancreas - ventral pancreatic bud abnormally encircles 2nd part of duodenum; forms a ring of pancreatic tissue that may cause duodenal narrowing
Pancreatic divisum - ventral and dorsal parts fail to fuse at 8 weeks. Common anomly; mostly asymptomatic, but may cause chronic abdominal pain and/or pancreatitis
Spleen - arises in mesentery of stomach (hence is mesodermal) but is supplied by foregut (celiac artery)
11
Q
Retroperitoneal structures
A
Retroperitoneal structures include GI structures that lack a mesentery and non-GI structures. Injuries to retroperitoneal structures can cause blood or gas accumulation in retroperitoneal space
SAD PUCKER
Suprarenal (adrenal) glands Aorta and IVC Duodenum (2nd through 4th parts) Pancreas (except tail) Ureters Colon (descending and ascending) Kidneys Esophagus (thoracic portion) Rectum (partially)
12
Q
Falciform ligament
A
Connects liver to anterior abdominal wall
Contains:
Ligamentum teres hepatis (derivate of fetal umbilical vein)
Derivative of ventral mesentery
13
Q
Hepatoduodenal ligament
A
Connects liver to duodenum
Contains:
Portal triad - proper hepatic artery, portal vein, common bile duct
Pringle maneuver - ligament may be compressed between thumb and index finger placed in omental foramen to control bleeding
Borders the omental foramen, which connects the greater and lesser sacs
14
Q
Gastrohepatic ligament
A
Connects liver to lesser curvature of stomach
Contains:
Gastric arteries
Separates greater and lesser sacs on the right.
May be cut during surgery to access liver sac
15
Q
Gastrocolic ligament
A
Connects greater curvature and transverse colon
Contains:
Gastroepiploic arteries
Part of grater omentum
16
Q
Gastrosplenic ligament
A
Connects greater curvature to spleen
Contains:
Short gastrics
Left gastrorpiploic vessels
Separates greater and lesser sacs on the left
17
Q
Splenorenal
A
Connects spleen to posterior abdominal wall
Contains:
Splenic artery and vein
Tail of pancreas
18
Q
Layers of gut wall
A
MSMS
Mucosa - epithelium, lamina, propria, muscularis mucosa
Submucosa - includes Submucosal nerve plexus (Meissner), Secretes fluid
Muscularis externa - include Myenteric plexus (Auerbach), Motility
Serosa (when intraperitoneal), adventitia (when retroperitoneal)
Frequencies of basal electric rhythm (slow waves)
Stomach - 3 waves/min
Duodenum - 12 waves/min
Ileum - 8-9 waves/min
19
Q
Digestive tract histology
A
Esophagus - Nonkeratinized stratified squamous epithelium
Stomach - gastric glands
Duodenum - Villi and microvilli increase absorptive surface Brunner glands (HCO3 secreting cells of submucosa) and crypts of Lieberkuhn
Jejunum - Plicae circulares and crypts of Lieberkuhn
Ileum - Peyer patches (lymphoid aggregates in lamina propria, submucosa), plicae circulares (proximal ileum), and crypts of Liberkuhn. Largest number of goblet cells in the SI
Colon - Colon has crypts of Lieberkuhn but no villi; abundant goblet cells
20
Q
Superior mesenteric artery syndrome
A
When the transverse portion (third part) of duodenum is entrapped between SMA and aorta, causing intestinal obstruction
21
Q
GI blood supply and innervation
A
1) Foregut embryologic origin
Celiac Artery Vagus Nerve (parasymp) Vertebral level = T12/L1
Pharynx (Vagus only) and lower esophagus (celiac artery only) to proximal duodenum; liver, gallbladder, pancreas, spleen (mesoderm)
2) Midgut
SMA
Vagus (parasymp)
L1
Distal duodenum to proximal 2/3 of transverse colon
3) Hindgut
IMA
Pelvic (parasymp)
L3
Distal 1/3 of transverse colon to upper portion of rectum; splenic flexure is a watershed region between SMA and IMA
22
Q
Celiac trunk
A
Branches of celiac trunk = Common hepatic, splenic, and Left Gastric. These constitute the main blood supply of the stomach
Short gastrics have poor anastomoses if splenic artery is blocked.
Strong anastomoses exist between:
L and R gastroepiploics
L and R gastrics
23
Q
Portosystemic anastomoses
A
1) Esophagus - Esophageal varices
L gastric vein and esophageal vein
2) Umbilicus - Caput medusae
Paraumbilical veins - small epigastric veins of the anterior abdominal wall
3) Rectum - Anorectal varices (NOT internal hemorrhoids)
Superior rectal vein - middle and inferior rectal veins
Varices of gut, butt, and caput are commonly seen with portal HTN
Treatment with a transjugular intrahepatic portosystemic shunt (TIPS) between the portal vein and hepatic vein relieves portal HTN by shunting blood to the systemic circulation bypassing the liver
24
Q
Pectinate (Dentate) line
A
Formed where endoderm (hindgut) meets ectoderm
1) Above pectinate line - internal hemorrhoids, adenocarcinoma
Arterial supply from superior rectal artery (branch of IMA)
Venous drainage: superior rectal vein - inferior mesenteric vein - portal system
Internal hemorrhoids receive visceral innervation and are therefore NOT PAINFUL
Lymphatic drainage to internal iliac lymph nodes
2) Below pectinate line - external hemorrhoids, anal fissures, squamous cell carcinoma
Arterial supply from inferior rectal artery (branch of internal pudendal artery)
Venous drainage: inferior rectal vein - internal pudendal vein - internal iliac vein - common iliac vein - IVC
External hemorrhoids receives somatic innervation (inferior rectal branch of pudendal nerve) and are therefore PAINFUL if thrombosed
Lymphatic drainage to superficial inguinal nodes
Anal fissure - tear in the anal mucosa below the Pectinate line: Pain while Pooping; blood on “toilet” Paper. Located Posteriorly since this area is Poorly Perfused
25
Liver anatomy
Apical surface of hepatocytes faces bile canaliculi. Basolateral surface faces sinusoids
Zone 1 - periportal zone
- affected 1st by viral hepatitis
- ingested toxins (cocaine)
Zone 2 - intermediate zone
- Yellow Fever
Zone 3 - pericentral vein (centrilobar) zone
- Affected 1st by ischemia
- Contains cytochrome P-450 system
- Most sensitive to metabolic toxins
- Site of alcoholic hepatitis
26
Femoral region
Organization - Lateral to Medial: Nerve-Artery-Vein-Empty space-Lymphatics
You go from lateral to medial to find your NAVEL
Femoral triangle - Contains femoral vein, artery, nerve
Venous near the penis
Femoral sheath - fascial tube 3-4 cm below inguinal ligament. Contains femoral vein, artery, and canal (deep inguinal lymph nodes) but not femoral nerve
27
Biliary structures - stones
Gallstones that reach the confluence of the common bile duct and pancreatic ducts at the ampulla of Vater can block both the common bile and pancreatic ducts (double duct sign), causing both cholangitis and pancreatitis, respectively
Tumors that arise in head of pancreas can cause obstruction of common bile duct alone leads to painless jaundice
28
Diaphragmatic hernia
Abdominal structures enter the thorax; may occur due to congenital defect of pleuroperitoneal membrane, or as a result of trauma.
Commonly occurs on left side due to relative protection of right hemidiaphragm by liver
Most commonly a hiatal hernia, in which stomach herniates upward through the esophageal hiatus of the diaphragm
Sliding hiatal hernia - most common. Gastroesophageal junction is displaced upward; "hourglass stomach"
Paraesophageal hernia - gastroesophageal junction is usually normal. Fundus protrudes into the thorax
29
Indirect inguinal hernia
Goes through internal (deep) inguinal ring, external (superficial) inguinal ring, and into the scrotum. Enters internal inguinal rung lateral to inferior epigastric artery.
Occurs in infants owing to failure of precessus vaginalis to close (can form hydrocele). Much more common in males
An indirect inguinal hernia follows the path of descent of the testes. Covered by all 3 layers of spermatic fascia
30
Direct inguinal hernia
Protrudes through the inguinal (Hasselbach) triangle. Bulges directly through abdominal wall medial to inferior epigastric artery. Goes through the external (superficial) inguinal ring only. Covered by external spermatic fascia. Usually in older men
MDs dont LIe
Medial to inferior epigastric artery = Direct
Lateral to inferior epigastric artery = Indirect
31
Femoral hernia
Protrudes below inguinal ligament through femoral canal below and lateral to pubic tubercle. More common in females
Leading cause of bowel incarceration
32
Hasselbach triangle
Inferior epigastric vessels
Lateral border of rectus abdominis
Inguinal ligament
33
Gastrin
```
1) Source:
G cells (antrum of stomach, duodenum)
```
2) Action:
Increases gastric H secretion (lower pH)
Increases growth of gastric mucosa
Increases gastric mucosa
3) Regulation:
Increased by stomach distention/alkalinization, amino acids, peptides, vagal stimulation
Decreased by pH
34
Somatostatin
```
1) Source:
D cells (pancreatic islets, GI mucosa)
```
2) Action:
Decreased gastric acid and pepsinogen secretion
Decreased pancreatic and SI fluid secretion
Decreased gallbladder contraction
Decreased insulin and glucagon release
3) Regulation:
Increased by acid
Decreased by vagal stimulation
4) Notes:
Inhibits secretion of GH, insulin, and other hormones (encourages somato-stasis).
Octreotide is an analog used to treat acromegaly, insulinoma, carcinoid syndrome, and variceal bleeding
35
Cholecystokinin
```
1) Source:
I cells (duodenum, jejunum)
```
```
2) Action:
Increases pancreatic secretion
Increases gallbladder contraction
Decreases gastric emptying
Increases sphincter of Oddi relaxation
```
3) Regulation:
Increased by fatty acids, amino acids
4) Notes:
CCK acts on neural muscarinic pathways to cause pancreatic secretion
36
Secretin
```
1) Source:
S cells (duodenum)
```
2) Action:
Increases pancreatic HCO3 secretion
Decreases gastric acid secretion
Increases bile secretion
3) Regulation:
Increased by acid, fatty acids in lumen of duodenum
4) Notes:
Increased HCO3 neutralizes gastric acid in duodenum, allowing pancreatic enzymes to function
37
Glucose-dependent insulinotropic peptide (GIP)
```
1) Source:
K cells (duodenum, jejunum)
```
2) Action:
Exocrine - Lowers gastric H secretion
Endocrine - Increases insulin release
3) Regulation:
Increased by fatty acids, amino acids, oral glucose
4) Notes:
Also known as gastric inhibitory peptide
Oral glucose load leads to increased insulin compared to IV equivalent due to GIP secretion
38
Motilin
1) Source:
Small intestine
2) Action:
Produces migrating motor complexes (MMCs)
3) Regulation:
Increased in fasting state
4) Notes:
Motilin receptor agonists (erythromycin) are used to stimulate intestinal peristalsis
39
Vasoactive intestinal polypeptide (VIP)
1) Source:
Parasympathetic ganglia in sphincters, gallbladder, small intestine
2) Action:
Increases intestinal water and electrolyte secretion
Increases relaxation of intestinal smooth muscle and sphincters
3) Regulation:
Increased by distention and vagal stimulation
Decreased by adrenergic input
4) Notes:
VIPoma - non alpha, non B islet cell pancreatic tumor that secretes VIP
Copious Watery Diarrhea, Hypokalemia, and Achlorhydria (WDHA syndrome)
40
Nitric Oxide
1) Source:
2) Action:
Increases smooth muscle relaxation, including lower esophageal sphincter (LES)
3) Regulation:
4) Notes:
Loss of NO secretion is implicated in increased LES tone of achalasia
41
Intrinsic factor
```
1) Source:
Parietal cells (stomach)
```
2) Action:
Vitamin B12-binding protein (required for B12 uptake in terminal ileum)
3) Regulation:
4) Notes:
Autoimmune destruction of parietal cells leads to chronic gastritis and pernicious anemia
42
Gastric acid
```
1) Source:
Parietal cells (stomach)
```
2) Action:
Lowers stomach pH
3) Regulation:
Increased by histamine, ACh, gastrin
Decreased by somatostatin, GIP, prostaglandin, secretin
4) Notes:
Gastrinoma: gastrin-secreting tumor that causes high levels of acid and ulcers refractory to medical therapy (like PPIs)
43
Pepsin
```
1) Source:
Chief cells (stomach)
```
2) Action:
Protein digestion
3) Regulation:
Increased by vagal stimulation, local acid
4) Notes:
Pepsinogen (inactive) is converted to pepsin (active) in the presence of H
44
HCO3
```
1) Source:
Mucosal cells (stomach, duodenum, salivary glands, pancreas) and Brunner glands (duodenum)
```
2) Action:
Neutralizes acid
3) Regulation:
Increased by pancreatic and biliary secretion with secretin
4) Notes:
HCO3 is trapped in mucus that covers the gastric epithelium
45
Pancreatic secretions - general
Isotonic fluid; low flow - high Cl, high flow - high HCO3
46
a-amylase
Pancreatic secretion
Role: Starch digestion
Secreted in active form
47
Lipases
Pancreatic secretion
Role: Fat digestion
48
Proteases
Pancreatic secretion
Role: Protein digestion
Includes trypsin, chymotrypsin, elastase, carboxypeptidases
Secreted as proenzymes also known as zymogens
49
Trypsinogen
Pancreatic secretion
Role: Converted to active enzyme trypsin - activation of other proenzymes and cleaving of additional trypsinogen molecules into active trypsin (positive feedback loop)
Converted to trypsin by enterokinase/enteropeptidase, a brush-border enzyme duodenal and jejunal mucosa
50
Carbohydrate absorption
Only monosaccharides (glucose, galactose, fructose) are absorbed by enterocytes
Glucose and galactose are taken up by SGLT1 (Na dependent). Fructose is taken up by facilitated diffusion by GLUT-5. All are transported to blood by GLUT-2
D-xylose absorption test: distinguishes GI mucosal damage from other causes of malabsorption
51
Vitamin/Mineral absorption
Iron - absorbed as Fe in duodenum
Folate - absorbed in small bowel
B12 - absorbed in terminal ileum, along with bile salts, requires intrinsic factor
IFB = Iron First Bro
Clinically relevant in patients with small bowel disease or after resection
52
Peyer patches
Unencapsulated lymphoid tissue found in lamina propria and submucosa of ileum. Contain specialized M cells that sample and present antigens to immune cells
B cells stimulated in germinal centers of Peyer patches differentiate into IgA-secreting plasma cells, which ultimately reside in lamina propria. IgA receives protective secretory component and is then transported across the epithelium to the gut to deal with intraluminal antigen
Think of IgA, the Intra-Gut-Antibody. And always say "secretory IgA"
53
Bile
Composed of bile salts (bile acids conjugated to glycine or taurine, making them water soluble), phospholipids, cholesterol, bilirubin, water, and ions. Cholesterol 7a-hydroxylase catalyzes rate-limiting step of bile synthesis
Functions:
Digestion and absorption of lipids and fat-soluble vitamins
Cholesterol excretion (body's only means of eliminating cholesterol)
Antimicrobial activity (via membrane disruption)
54
Bilirubin
Heme is metabolized by heme oxygenase to biliverdin, which is subsequently reduced to bilirubin.
Unconjugated bilirubin is removed from blood by liver, conjugated with glucuronate, and excreted in bile
Direct bilirubin - conjugated with glucuronic acid; water soluble
Indirect bilirubin - unconjugated; water insoluble
55
Salivary gland tumors
Generally benign – in parotid gland
1) Pleomorphic adenoma: (benign mixed tumor) – most common.
Presents as painless, mobile mass. Made of chondromyxoid stroma and epithelium and recurs if incompletely excised or ruptured during surgery.
2) Mucoepidermoid carcinoma: most common malignant tumor. Has mucous and Squamous parts. Painless, slow growing mass.
3) Warthin tumor (papillary cystadenoma lymphomatosum): benign cystic tumor with germinal centers
56
Achalasia
(absence of relaxation): Failure of relaxation of LES due to loss of myenteric plexus. High LES resting pressure and uncoordinated peristalsis – progressive dysphagia to solids and liquids (vs obstruction – solid only).
Ba swallow shows dilated esophagus with an area of distal stenosis. Associated with higher risk of esophageal squamous cell carcinoma. “Birds beak” on Ba swallow.
Secondary achalasia = can come from chagas disease (T. Cruzi infection) or Malignancies (mass effect or paraneoplastic)
57
Boerhaave Symdrome
Esophageal
Transmural, usually distal esophageal with pneumomediastinum due to violent retching; surgical emergency
58
Eosinophilic esophagitis
Infiltration of eosinophils in the esophagus in atopic patients. Food allergens - dysphagia, heartburn, strictures. Unresponsive to GERD therapy
59
Esophageal strictures
Associated with lye ingestion and acid reflux
60
Esophageal varices
Dilated submucosal veins in lower 1/3 of esophagus secondary to portal HTN.
Common in alcoholics, may be source of upper GI bleeding
61
Esophagitis
Associated with reflux, infection in immunocompromised (Candida: white pseudomembrane, HSV-1: punched-out ulcers, CMV: linear ulcers) or chemical ingestion
62
Gastroesophageal reflux disease
GERD
Commonly presents as heartburn and regurgitation upon lying down. May also present with nocturnal cough and dyspnea, adult-onset asthma. Decrease in LES tone
63
Mallory-Weiss syndrome
Mucosal lacerations at the gastroesophageal junction due to severe vomiting. Leads to hematemesis. Usually found in alcoholics and bulimics.
64
Plummer-Vinson Syndrome
Triad of: Dysphagia, Iron deficiency anemia, Esophageal Webs
"DIE"
May be associated with glossitis. Increased risk of esophageal squamous cell carcinoma (Plumbers DIE)
65
Sclerodermal esophageal dysmotility
Esophageal smooth muscle atrophy leads to lower LES pressure and dysmotility. This causes acid reflux and dysphagia leading to stricture, Barrett esophagus, and aspiration. Part of CREST syndrome
66
Barrett esophagus
Glandular metaplasia - replacement of nonkeratinized stratified squamous epithelium with intestinal epithelium (nonciliated columnar with goblet cells) in distal esophagus.
Due to chronic acid reflux (GERD). Associated with esophagitis, esophageal ulcers, and increased risk of esophageal adenocarcinoma
67
Esophageal cancer
Can be squamous cell carcinoma or adenocarcinoma. Typically presents with progressive dysphagia (first solid, then liquids) and weight loss; poor prognosis. Risk factors are AABCDEFFGH
```
Achalasia
Alcohol - Squamous
Barrett esophagus - adeno
Cigarettes - both
Diverticula (Zenker) - squamous
Esophageal web - squamous
Familial
Fat (obesity) - adeno
GERD - adeno
Hot liquids - squamous
```
Worldwide, squamous cell is more common.
Adenocarcinoma is most common type in America
Squamous cell - upper 2/3
Adenocarcinoma - lower 1/3
68
Acute gastritis (erosive)
Disruption of mucosal barrier leading to inflammation
Can be caused by:
1) NSAIDs - lower PGE2 leading to lower gastric mucosa protection
2) Burns (Curling ulcer) - lower plasma volume - sloughing of gastric mucosa
3) Brain injury (Cushing ulcer) - increased vagal stimulation leads to increased ACh which raises H production
Especially common among alcoholics and patients taking daily NSAIDs (patients with RA)
"Burned by a curling iron"
"Always cushion the brain"
69
Chronic gastritis (nonerosive)
1) Type A (fundus/body) - Autoimmune disorder characterized by Autoantibodies to parietal cells, pernicious Anemia, and Achlorhydria. Associated with other autoimmune disorders
2) Type B (antrum) - Most common type. Caused by H Pylori infection. Increased risk of MALT lymphoma
A comes before B
A = autoimmune = first part of stomach
B = bacteria = second part of stomach (antrum)
70
Menetrier Disease
Gastric hyperplasia of mucosa leading to hypertrophied rugae, excess mucus production with resultant protein loss and parietal cell atrophy with decreased acid production.
Precancerous.
Rugae of stomach are so hypertrophied that they look like brain gyri
71
Stomach cancer
Commonly gastric adenocarcinoma; lymphoma; carcinoid (rare).
Early aggressive local spread with node/liver metastases. Often presents with weight loss, early satiety, and in some cases acanthosis nigricans
1) Intestinal - associated with H pylori, dietary nitrosamines (smoked foods), tobacco smoking, achlorhydria, chronic gastritis.
Commonly on lesser curvature; looks like ulcer with raised margins
2) Diffuse - not associated with H pylori; signet ring cells (mucin-filled cells with peripheral nuclei); stomach wall grossly thickened and leathery (linitis plastica)
Virschow node = involvement of left supraclavicular node by metastasis from stomach
Krukenberg tumor = bilateral metastases to ovaries. Abundant mucin-secreting, signet-ring cells
Sister Mary Joseph nodule = subcutaneous periumbilical metastasis
72
Gastric vs Duodenal Ulcers in Peptic ulcer disease
1) Gastric
Pain - can be greater with meals - weight loss
H pylori - 70%
Mechanism - decreased mucosal protection against gastric acid
Other causes - NSAIDs
Risk of carcinoma - increased
Other - Biopsy margins to rule out malignancy
2) Duodenal
Pain - decreases with meals - weight gain
H Pylori - 100% almost
Mechanism - Decreased mucosal protection or increased gastric acid secretion
Other causes - Zollinger-Ellison Syndrome
Risk of carcinoma - generally benign
Other - Hypertrophy of Brunner glands
73
Ulcer complications
1) Hemorrhage
Gastric, duodenal (posterior > anterior).
Ruptured gastric ulcer on the lesser curvature of stomach leads to bleeding from L gastric artery.
An ulcer on the posterior wall of duodenum leads to bleeding from gastroduodenal artery
2) Perforation
Duodenal (anterior > posterior)
May see free air under diaphragm with referred pain to the shoulder via phrenic nerve
74
Malabsorption syndromes - general
Can cause diarrhea, steatorrhea, weight loss, weakness, vitamin and mineral deficiencies
```
Celiac Disease
Disaccharidase deficiency
Pancreatic insufficiency
Tropical sprue
Whipple Disease
```
75
Celiac Disease
A malabsorption syndrome
Autoimmune-mediated intolerance of gliadin (gluten protein found in wheat) leads to malabsorption and steatorrhea
Associated with HLA-DQ2, HLA-DQ8
Also associated with Northern European decent, dermatitis, herpetiformis, lower bone density
Findings = anti-endomysial, anti-tissue transglutaminase, and anti-gliadin antibodies; blunting of villi; and lymphocytes in lamina propria. Moderately increased risk of malignancy (T cell Lymphoma)
Lower mucosal absorption primarily affects distal duodenum and/or proximal jejunum
Tx = gluten-free diet
76
Disaccharidase Deficiency
A malabsorption syndrome
Most common is lactase deficiency - milk intolerance. Normal-appearing villi. Osmotic diarrhea.
Since lactase is located at tips of intestinal villi, self-limited lactase deficiency can occur following injury (viral enteritis)
Lactose intolerance test: (+) for lactase deficiency if administration of lactose produces symptoms and serum glucose rises
77
Pancreatic insufficiency
A malabsorption syndrome
Due to cystic fibrosis, obstructing cancer, chronic pancreatitis.
Causes malabsorption of fat and fat-soluble vitamins (ADEK) as well as B12
Increased neutral fat in stool
D-xylose absorption test - normal urinary excretion in pancreatic insufficiency; lower excretion with intestinal mucosal defects or bacterial overgrowth
78
Tropical sprue
A malabsorption syndrome
Similar findings as celiac sprue (affects small bowel), but responds to antibiotics. Cause is unknown, but seen in residents of or recent visitors to tropics
79
Whipple Disease
A malabsorption syndrome
Infection with Tropheryma whipplei (gram positive)
PAS (+) foamy macrophages in intestinal lamina propria, mesenteric nodes.
Cardiac symptoms, Arthralgias, and Neurologic symptoms are common. Most often occurs in older men
80
Crohn Disease
1) location - Any portion of GI tract, usually the terminal ileum and colon. Skip lesions, rectal sparing.
2) Gross morphology - Transmural inflammation - fistulas. Cobblestone mucosa, creeping fat, bowel wall thickening ("string sign" on Ba swallow XR), linear ulcers, fissures
3) Microscopic morphology - Noncaseating granulomas and lymphoid aggregates (Th1 mediated)
4) Complications - Strictures (leading to obstruction), fistulas (including enterovesical fistulae, which can cause recurrent polymicrobial UTIs), perianal disease, malabsorption, nutritional depletion, colorectal cancer, gallstone
5) Intestinal manifestation - Diarrhea that may or may not be bloody
6) Extraintestinal manifestations - Migratory polyarthritis, erythema nodosum, ankylosing spondylitis, pyoderma gangrenosum, aphthous ulcers, uveitis, kidney stones
7) Tx - Corticosteroids, azathioprine, antibiotics (ciprofloxacin, metronidazole), infliximab, adalimumab
81
Ulcerative Colitis
1) location - Colitis = colon inflammation. Continuous colonic lesions, always with rectal involvement
2) Gross morphology - Mucosal and submucosal inflammation only. Friable mucosal pseudopolyps with freely hanging mesentery. Loss of haustra - "lead pipe" on imaging
3) Microscopic morphology - Crypt abscesses and ulcers, bleeding, no granulomas (Th2 mediated)
4) Complications - Malnutrition, sclerosing cholangitis, toxic megacolon, colorectal carcinoma (worse with right sided colitis or pancolitis)
5) Intestinal manifestation - Bloody diarrhea
6) Extraintestinal manifestations - Pyoderma gangrenosum, erythema nodosum, primary sclerosing cholangitis, ankylosing spondylitis, aphthous ulcers, uveitis
7) Tx - 5-aminosalicylic preparations (mesalamine), 6-MP, infliximab, colectomy
UC causes ULCCCERS
```
Ulcers
Large Intestine
Continuous, Colorectal carcinoma, Crypt abscesses
Extends proximally
Red diarrhea
Sclerosing cholangitis
```
82
Irritable Bowel Syndrome
Recurrent abdominal pain associated with at least 2 of the following:
Pain improves with defecation
Change in stool frequency
Change in appearance of stool
No structural abnormalities. Most common in middle-aged women. Chronic symptoms. May present with diarrhea, constipation, or alternation symptoms. Pathophysiology is multifaceted. Treat the symptoms
83
Appendicitis
Acute inflammation of the appendix due to obstruction by fecalith (in adults) or lymphoid hyperplasia (in children)
Initial diffuse perumbilical pain migrates to McBurnery point (1/3 the distance from right anterior superior iliac spine to umbilicus).
Nausea, fever; may perforate - peritonitis; may elicit psoas, obturator, Rovsing sign, guarding and rebound tenderness on exam
Ddx = diverticulitis (elderly), ectopic pregnancy (use B-hCG to rule out)
Tx = appendectomy
84
Diverticulum
Blind pouch protruding from the alimentary tract that communicates with the lumen of the gut. Most diverticula (esophagus, stomach, duodenum, colon) are acquired and are termed "false" in that they lack or have an attenuated muscularis externa. Most often in sigmoid colon
"True" diverticulum - all 3 gut wall layers outpouch (Meckel)
"False" diverticulum or pseudodiverticulum - only mucosa and submucosa outpouch. Occur especially where vasa recta perforate muscularis externa
85
Diverticulosis
Many false diverticula of the colon, commonly sigmoid. Common (in 50% of people > 60)
Caused by increased intraluminal pressure and focal weakness in colonic wall. Associated with low-fiber diets.
Often asymptomatic or associated with vague discomfort. A common cause of hematochezia.
Complications include diverticulitis, fistulas
86
Diverticulitis
Inflammation of diverticula classically causing LLQ pain, fever, leukocytosis.
May perforate - peritonitis, abscess formation, or bowel stenosis. Give antibiotics
May also cause colovesical fistula (fistula with bladder) - pneumaturia
Sometimes called "left-sided appendicitis" due to overlapping clinical presentation
87
Zenker diverticulum
Pharyngoesophageal FALSE diverticulum
herniation of mucosal tissue at Killian triangle between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor
Presenting symptoms = dysphagia, obstruction, foul breath from trapped food particles (halitosis)
Most common in elderly males
88
Meckel diverticulum
TRUE diverticulum. Persistence of the vitelline duct.
May contain ectopic acid-secreting gastric mucosa and/or pancreatic tissue.
*Most common congenital anomaly of GI tract.
Can cause melena, RLQ pain, intussusception, volvulus, or obstruction near terminal ileum.
Contrast with omphalomesenteric cyst = cystic dilation of vitelline duct
Dx = pertechnetate study for uptake by ectopic gastric mucosa
The five 2's
2 inches long
2 feet from ileocecal valve
2% of population
Commonly presents in first 2 years of life
May have 2 types of epithelia (gastric/pancreatic)
89
Malrotation
Anomaly of midgut rotation during fetal development leading to improper positioning of bowel, formation of fibrous bands (Ladd bands)
Can lead to volvulus, duodenal obstruction
90
Volvulus
Twisting of portion of bowel around its mesentery; can lead to obstruction and infarction. Can occur throughout the GI tract.
Midgut volvulus more common in infants and children. Sigmoid volvulus more common in elderly
91
Intussusception
Telescoping of proximal bowel segment into distal segment, commonly at ileocecal junction.
Compromised blood supply leads to intermittent abdominal pain often with "currant jelly" stools. Unusual in adults (associated with intraluminal mass or tumor that acts as lead point that is pulled into the lumen)
Majority of cases occur in children (usually idiopathic; may be associated with recent enteric or respiratory viral infection)
Abdominal emergency in early childhood, with bull's eye appearance on ultrasound
92
Hirschsprung Disease
Congenital megacolon characterized by lack of ganglion cells/enteric nervous plexuses (Auerbach and Meissner) in segment of colon. Due to failure of neural crest cell migration. Associated with mutations in RET gene
presents with bilious emesis, abdominal distention, and failure to pass meconium leading to chronic constipation
Normal portion of the colon proximal to the aganglionic segment is dilated, resulting in a "transition zone." Involves rectum.
Think of Hirschsprung as a giant spring that has sprung in the colon. Risk higher with Down Syndrome
Diagnosed by rectal suction biopsy
Tx = resection
93
Acute mesenteric ischemic
Critical blockage of intestinal blood flow (often embolic occlusion of SMA) leading to small bowel necrosis causing abdominal pain out of proportion to physical findings
May see red "currant jelly" stools
94
Adhesion
Fibrous band of scar tissue; commonly forms after surgery; most common cause of small bowel obstruction.
Can have well-demarcated necrotic zones
95
Angiodysplasia
Tortuous dilation of vessels leads to hematochezia
Most often found in cecum, terminal ileum, ascending colon. More common in older patients. Confirmed by angiography
96
Duodenal atresia
Causes early bilious vomiting with proximal stomach distention ("double bubble" on XR) bc of failure of small bowel recanalization. Associated with Down Syndrome
97
Ileus
Intestinal hypomotility without obstruction leading to constipation and decreased flatus; distended/tympanic abdomen with reduced bowel sounds.
Associated with abdominal surgeries, opiates, hypokalemia, sepsis
Tx = bowel rest, electrolyte correction, cholinergic drugs (stimulate intestinal motility)
98
Ischemic colitis
Reduction in intestinal blood flow causes ischemia. Pain after eating leading weight loss.
Commonly occurs at watershed areas (splenic flexure, distal colon)
Typically affects elderly
99
Meconium ileus
In cystic fibrosis, meconium plug obstructs intestine, preventing stool passage at birth
100
Necrotizing enterocolitis
Seen in premature, formula-fed infants with immature immune system
Necrosis of intestinal mucosa (primarily colonic) with possible perforation, which can lead to pneumatosis intestinalis, free air in abdomen, portal venous gas
101
Colonic polyps
Small growths of tissue within the colon. May be neoplastic or non-neoplastic. Grossly characterized as flat, sessile, or pedunculated (on a stalk) on the basis of protrusion into colonic lumen. Generally classified by histologic type
102
Hyperplastic polyps
Non-neoplastic
Generally smaller and majority located in rectosigmoid area
103
Hamartomatous polyps
Non-neoplastic
Solitary lesions do not have a significant risk of malignant transformation. Growths of normal colonic tissue with distorted architecture
Associated with Peutz-Jeghers syndrome and juvenile polyposis
104
Adenomatous polyps
Neoplastic
Via chromosomal instability pathway with mutations in APC and KRAS.
Tubular histology has less malignant potential than villous; tubulovillous has intermediate malignant potential
105
Serrated polyps
Premalignant
Via CpG hypermethylation phenotype pathway with microsatellite instability and mutations in BRAF
"saw-tooth" pattern of crypts on biopsy
Up to 20% of cases of sporadic CRC
106
Familial adenomatous polyposis (FAP)
Autosomal Dom mutation in APC tumor suppressor gene on chromosome 5q.
2 hit hypothesis
100% progresses to CRC unless colon is resected. Thousands of polyps arise starting after puberty; pancolonic; always involves rectum
107
Gardner Syndrome
FAP+ osseous and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium, impacted/supernumerary teeth
108
Turcot Syndrome
FAP + malignant CNS tumor. "Turcot = Turban"
109
Peutz-Jeghers Syndrome
Autosomal Dom syndrome featuring numerous hamartomas throughout GI tract, along with hyperpigmented mouth, lips, hands. genitalia
Associated with higher risk of CRC
110
Juvenile Polyposis Syndrome
Autosomal Dom syndrome in children (typically younger than 5) featuring numerous hamartomatous polyps in the colon, stomach, small bowel.
Associated with higher risk of CRC
111
Lynch Syndrome
Previously known as "hereditary nonpolyposis colorectal cancer (HNPCC)"
Autosomal Dom mutation of DNA mismatch repair genes with subsequent microsatellite instability
80% progresses to CRC
Proximal colon is always involved
Associated with endometrial, ovarian, and skin cancers
Can be identified clinically in families using 3-2-1 rule
3 relatives with Lynch Syndrome-associated cancers across 2 generations, 1 of whom must be diagnosed before age 50 years old.
112
Colorectal cancer
Most patients are over 50. 25% have a family history
Adenomatous and serrated polyps, familial cancer syndromes, IBD, tobacco use, diet of processed meat with low fiber
Rectosignmoid > ascending > descending
Ascending - exophytic mass, iron deficiency anemia, weight loss
Descending - infiltrating mass, partial obstruction, colicky pain, hematochezia
Rarely, presents with Strep Bovis bacteremia
Dx = iron deficiency anemia in males (especially over 50 years old) and postmenopausal female raises suspicion
Screen patients > 50 years old with colonoscopy, flexible sigmoidoscopy, or stool occult blood test
Apple core lesion seen on Ba enema XR
CEA tumor marker good for monitoring recurrence, not useful for screening
113
Molecular pathogenesis of colorectal cancer
There are 2 molecular pathways that lead to CRC
1) Microsatellite instability pathway (15%): DNA mismatch repair gene mutation leads to sporadic and Lynch Syndrome. Mutations accumulate, but no defined morphologic correlates
2) APC/B-catenin (chromosomal instability) pathway (85%) leads to sporadic cancer
Loss of APC gene puts normal colon at risk. (decreased intercellular adhesion and increased proliferation)
KRAS mutation puts the at risk colon into and adenoma (unregulated intracellular signal transduction).
Loss of tumor suppressor gene (p53, DCC) turns the adenoma into carcinoma (increased tumorigenesis)
"order of events = AK 53"
114
Cirrhosis and portal HTN
Cirrhosis - diffuse bridging fibrosis and nodular regeneration via satellite cells disrupts normal architecture of liver; increased risk of hepatocellular carcinoma (HCC)
Etiologies: alcohol (60-70% of cases in the US), chronic viral hepatitis, biliary disease, genetic/metabolic disorders
Portosystemic shunts partially alleviate portal HTN - esophageal varices, caput medusae, anorectal varices
115
Serum markers of liver and pancreas pathology
1) Alkaline phosphatase (ALP) - cholestatic and obstructive hepatobiliary disease, HCC, infiltrative disorders, bone disease
2) Aminotransferases (AST and ALT) (often called "Liver enzymes") - Viral hepatitis (ALT > AST), Alcoholic hepatitis (AST > ALT)
3) Amylase - Acute pancreatitis, mumps
4) Ceruloplasmin - Reduced in Wilson Disease
5) y-glutamyl transpeptidase (GGT) - increased in various liver and biliary diseases (just as ALP can), but NOT in bone disease; associated with alcohol use
6) Lipase - Acute pancreatitis (most specific)
116
Reye Syndrome
Rare, often fatal childhood hepatic encephalopathy.
Findings: mitochondrial abnormalities, fatty liver (microvascular fatty change), hypoglycemia, vomiting, hepatomegaly, coma.
Associated with viral infection (esp VZV and influenza B) that has been treated with aspirin.
Mech: Aspirin metabolites lower B-oxidation by reversible inhibition of mitochondrial enzymes. Avoid aspirin in children, except in those with Kawasaki Disease*
117
Alcoholic liver disease
1) Hepatic steatosis - Macrovascular fatty change that may be reversible with alcohol cessation
2) Alcoholic hepatitis - Requires sustained, long-term consumption. Swollen and necrotic hepatocytes with neutrophilic infiltration. Mallory bodies (intracytoplasmic eosinophilic inclusions of damaged keratin filaments)
Make a toAST with alcohol - AST > ALT (ratio usually > 1.5)
3) Alcoholic cirrhosis - Final and irreversible form. Micronodular, irregularly shrunken liver with "hobnail" appearance. Sclerosis around central vein (zone 3)
Manifestations of chronic liver disease (jaundice, hypoalbuminemia)
118
Non-alcoholic fatty liver disease
Metabolic syndrome (insulin resistance) leads to fatty infiltration of hepatocytes causing cellular "ballooning" and eventual necrosis. May cause cirrhosis and HCC. Independent of alcohol use
ALT > AST
119
Hepatic encephalopathy
Cirrhosis leads to portosystemic shunts leading to reduced NH3 metabolism causing neuropsychiatric dysfunction
Spectrum from disorientation/asterixis (mild) to difficult arousal or coma (severe).
Triggers:
Increased NH3 production and absorption (due to dietary protein, GI bleed, constipation, infection)
Decreased NH3 removal (due to renal failure, diuretics, bypassed hepatic blood flow post-TIPS)
Tx = lactulose (increases NH4 generation) and rifaximin
120
Hepatocellular Carcinoma/Hepatoma
Most common primary malignant tumor of liver in adults. Associated with HBV (+/- cirrhosis) and all other causes of cirrhosis (including HCV, alcoholic and non-alcoholic fatty liver disease, autoimmune disease, hemochromatosis, alpha1 antitrypsin deficiency, Wilson Diseaes) and specific carcinogens (aflatoxin from Aspergillus)
May lead to Budd-Chiari Syndrome
Findings: jaundice, tender hepatomegaly, ascites, polycythemia, anorexia. Spreads hematogenously
Dx = increased alpha-fetoprotein; ultrasound or contrast CT/MRI, biopsy
121
Cavernous hemangioma
Liver tumor
Common, benign liver tumor; typically occurs at age 30-50 years. Biopsy contraindicated bc of risk of hemorrhage
122
hepatic adenoma
Liver tumor
Rare, benign liver tumor, often related to oral contraceptive or anabolic steroid use; may regress spontaneously or rupture (abdominal pain and shock)
123
Angiosarcoma
Liver tumor
Malignant tumor of endothelial origin; associated with exposure to arsenic, vinyl chloride
124
Metastases
Liver tumor
GI malignancies, breast, and lung cancer. Most common overall**
125
Budd-Chiari Syndrome
Thrombosis or compression of hepatic veins with centrilobular congestion and necrosis leads to congestive liver disease (hepatomegaly, varices, abdominal pain, eventual liver failure)
Absence of JVD
Associated with hypercoagulable states, polycythemia vera, postpartum state, HCC
May cause nutmeg liver (mottled appearance)
126
Alpha1-antitrypsin deficiency
Misfolded gene product protein aggregates in hepatocellular ER leading to cirrhosis with PAS (+) globules in liver.
Codominant trait
In lungs, lower alpha1 antitrypsin leads to uninhibited elastase in alveoli leading to less elastic tissue causing panacinar emphysema
127
Jaundice
Abnormal yellowing of the skin and/or sclera due to bilirubin deposition. Occurs at high bilirubin levels ( > 2.5 mg/dL) in blood secondary to increased production or defective metabolism
128
Unconjugated (indirect) hyperbilirubinemia
Hemolytic, physiologic (newborn), Crigler-Najjar, Gilbert Syndrome
129
Conjugated (direct) hyperbilirubinemia
Biliary tract obstruction: gallstones, cholangiocarcinoma, pancreatic or liver cancer, liver fluke.
Biliary tract disease:
Primary sclerosing cholangitis
Primary biliary cirrhosis
Excretion defect: Dubin-Johnson syndrome, Rotor syndrome
130
Mixed (direct and indirect) hyperbilirubinemia
Hepatitis, Cirrhosis
131
Physiologic neonatal jaundice
At birth, immature UDP-glucuronosyltransferase leads to unconjugated hyperbilirubinemia causing jaundice/kernicterus (bilirubin deposition in brain, particularly basal ganglia)
Tx = phototherapy (converts unconjugated bilirubin to water-soluble form)
132
Gilbert Syndrome
Hereditary hyperbilirubinemia
Mildly reduced UDP-glucuronosyltransferase conjugation and impaired bilirubin uptake. Asymptomatic or mild jaundice.
Increased unconjugated bilirubin without overt hemolysis. Bilirubin increases with fasting and stress
Very common. No clinical consequences
133
Crigler-Najjar Syndrome, type 1
Hereditary hyperbilirubinemia
Absent UDP-glucuronosyltransferase. Presents early in life; patients die within a few years
Findings: jaundice, kernicterus (bilirubin deposition in brain), increased unconjugated bilirubin
Tx = plasmapheresis and phototherapy
Type 2 is less severe and responds to phenobarbital, which increases liver enzyme synthesis
134
Dubin-Johnson Syndrome
Hereditary hyperbilirubinemia
Conjugated hyperbilirubinemia due to defective liver excretion. Grossly black liver. Benign
Rotor Syndrome** is similar but even milder and does not cause black liver
135
Wilson Disease (hepatolenticular degeneration)
Inadequate hepatic copper excretion and failure of copper to enter circulation as ceruloplasmin. Leads to copper accumulatio, especially in liver, brain, cornea, kidneys (Fanconi syndrome), and joints
Autosomal recessive inheritance (chromosome 13). Copper is normally excreted into bile by hepatocyte copper transporting ATPase (ATP7B gene)
Treatment includes chelation with penicillamine or trientine, oral zinc
Characterized by:
Low Ceruloplasmin, Cirrhosis, Corneal deposits (Kayser-Fleischer rings). Copper accumulation, Carcinoma (HCC)
Hemolytic anemia
Basal ganglia degeneration (parkinsonian symptoms)
Asterixis
Dementia, Dyskinesia, Dysarthria
Copper is Hella BAD
136
Hemochromatosis
Hemosiderosis is the deposition of hemosiderin (iron), which stains blue; hemochromatosis is the disease caused by this iron deposition
Classic triad of micronodular Cirrhosis, Diabetes Mellitus and Skin pigmentation - "Bronze Diabetes"
results in HF, testicular atrophy, increased risk of HCC
Disease may be primary (auto recess) or secondary to chronic transfusion therapy (B-thalassemia major)
Increased ferritin
Increased Fe
Low TIBC
All this = high transferrin saturation
Can be identified on biopsy with Prussian blue stain
total body iron may reach 50g, enough to set off metal detectors at airports
Primary hemochromatosis due to C282Y or H63D mutation on HFE gene. Associated with HLA-A3
Iron loss through menstruation slows progression in women
Treatment of hereditary hemochromatosis: repeated phlebotomy, chelation with defarasirox, deferoxamine, deferiprone (oral)
137
Biliary tract disease - general
May present with pruritus, jaundice, dark urine, light-colored stool, hepatosplenomegaly. Typically with cholestatic pattern of LFTs (increased conjugated bilirubin, increased cholesterol, increased ALP)
138
Secondary biliary cirrhosis
Extrahepatic biliary obstruction leads to increased pressure in intrahepatic ducts leading to injury/fibrosis and bile stasis
Patients with known obstructive lesions (gallstones, biliary strictures, pancreatic carcinoma)
May be complicated by ascending cholangitis
139
Primary biliary cirrhosis
Autoimmune reaction leading to lymphocytic infiltrate + granulomas causing destruction of intralobular bile ducts
Classically in middle-aged women
Anti-mitochondrial antibody (+), including IgM
Associated with other autoimmune conditions (CREST, Sjogren syndrome, RA, Celiac)
140
Primary sclerosing cholangitis
Unknown cause of concentric "onion skin" bile duct fibrosis causing alternating strictures and dilation with "beading" of intra-and extrahepatic bile ducts on ERCP, magnetic resonance cholangiopancreatography (MRCP).
Classically in young men with IBD
Hypergammaglobulinemia (IgM). MPO-ANCA/p-ANCA (+)
Associated with UC. Can lead to secondary biliary cirrhosis, cholangiocarcinoma
141
Gallstones (cholelithiasis)
Increased cholesterol and/or bilirubin, lower bile salts, and gallbladder stasis all cause stones
2 types of stones
1) Cholesterol stones (radiolucent with 10-20% opaque due to calcifications) - 80% of stones.
Associated with obesity, Crohn, advanced age, clofibrate, estrogen therapy, multiparity, rapid weight loss, Native American origin
2) Pigment stones (black = radiopaque, Ca bilirubinate, hemolysis; brown = radiolucent, infection) - seen in patients with chronic hemolysis, alcoholic cirrhosis, advanced age, biliary infections, total parenteral nutrition (TPN)
Stones most often cause cholecystitis; also ascending cholangitis, acute pancreatitis, bile stasis
Can also lead to biliary colic - neurohormonal activation (by CCK after a fatty meal) triggers contraction of gallbladder, forcing a stone into the cystic duct. May present without pain (in diabetes)
Can cause fistula between gallbladder and small intestine, leading to air in biliary tree and allowing the passage of gallstones into the intestinal tract. Gallstone may obstruct ileocecal valve leading to gallstone ileus
Diagnose with ultrasound. Treat with cholecystectomy if symptomatic
```
Risk factors = 4 F's
Female
Fat
Fertile (pregnant)
Forty
```
Charcot triad of cholangitis:
Jaundice
Fever
RUQ pain
142
Cholecystitis
Acute or chronic inflammation of gallbladder. Usually from cholelithiasis (gallstones); most commonly blocking the cystic duct leading to secondary infection; rarely ischemia or primary infection (CMV)
Murphy sign (+) - inspiratory arrest on RUQ palpation due to pain. Increased ALP if bile duct becomes involved (ascending cholangitis)
Diagnose with ultrasound or cholescintigraphy (HIDA, or hepatobiliary iminodiacetic acid scan)
143
Porcelain gallbladder
Calcified gallbladder due to chronic cholecystitis; usually found incidentally on imaging
Tx = prophylactic cholecystectomy due to high rates of gallbladder carcinoma
144
Acute pancreatitis
Autodigestion of pancreas by pancreatic enzymes
Causes: idiopathic, Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune disease, Scorpion sting, Hypercalcemia/Hypertriglyceridemia ( > 1000), ERCP, Drugs (sulfa drugs, NRTIs, protease inhibitors) - GET SMASHED
Clinical presentation - epigastric abdominal pain radiating to back, anorexia, nausea
Labs - high amylase and lipase (higher specificity)
Can lead to DIC, ARDS, diffuse fat necrosis, hypocalcemia (ca collects in pancreatic Ca soap deposits), pseudocyst formation, hemorrhage, infection, multiorgan failure
Complications - pancreatic pseudocyst (lined by granulation tissue, not epithelium; can rupture and hemorrhage)
145
Chronic pancreatitis
Chronic inflammation, atrophy, calcification of the pancreas. Major causes are alcohol abuse and idiopathic
Mutations in CFTR (cystic fibrosis) can cause chronic pancreatic insufficiency
Can lead to pancreatic insufficiency leading to steatorrhea, fat soluble vitamin deficiency, diabetes mellitus
Amylase and lipase may or may not be elevated (almost always elevated in acute pancreatitis)
146
Pancreatic adenocarcinoma
Average survival - 1 year after diagnosis. Very aggressive tumor arising from pancreatic ducts (disorganized glandular structure with cellular infiltration); already metastasized at presentation; tumors more common in pancreatic head (leading to obstructive jaundice). Associated with CA 19-9 tumor marker (also CEA, less specific)
```
Risk factors:
Tobacco use
Chronic pancreatitis (especially more than 20 years)
Diabetes
Age > 50
Jewish and black males
```
Often presents with:
Abdominal pain radiating to back
Weight loss (due to malabsorption and anorexia)
Migratory thrombophlebitis - redness and tenderness on palpation of extremities (Trousseau Syndrome)
Obstructive jaundice with palpable, nontender gallbladder (Courvoisier sign)
Tx = Whipple procedure, chemotherapy, radiation therapy
