GI pathology

Hypertrophic pyloric stenosis

Narrowing of distal lumen (pyloric canal in stomach) due to thickening of circular muscle of the wall in the stomachVomiting (non-bilous)More common in females than males

Duodenal atresia/stenosis

Lack of recanalization; mess-up in rotation, volvulus, gastroschisis, and other factors--the lumen of the duodenum doesn't reopenAtresia: In upper duodenum;Blood supply to region is compromised and segment will die resulting in complete loss of region; gut obstructions from this, 25% in duodeunum, 50% in ileumStenosis: in lower duodenum; blood supply in compromised resulting in narrowing of that region

Annular pancreas

Formation of bi-lobed ventral pancreatic bud that migrates around duodenum in opposite directionsStrangulation of duodenumDuodenal stenosis or atresia

Meckel's diverticulum

Stalk of yolk sac left behind; congenital diverticulumFollows the rule of 2 (2% population, 2 in long, 2 ft proximal to ileocecal junction)Mucosa similar to adjacent ileumComplications include hemorrhage, intestinal obstruction, diverticulitis, and perforation

Gut duplication

Mostly in esophagus and ileocecla/ilela regions

Situs inversus

complete or partial (abdomen only) reversal of organs

Diabetes and motility

likely due to autonomic neuropathyImpaired gastric emptying (gastroparesis), altered pharyngeal and esophageal contractions

Essential fructosuria

Lack of fructokinase in liver and kidneyBenign disorder; symptoms are dependent on amount of fructose and sucrose intake

Hereditary fructose intolerance

Lack of aldolase B in liver, small intestine, and kidneyPotentially lethalSevere hypoglycemia and vomiting following fructose intakeFructose in infants-->vomiting, jaundice, hepatomegaly, hemorrhage, and hepatic failure

Hereditary fructose-1,6-bisphosphate deficiency

Severely impaired hepatic gluconeogenesisEpisodes of hypoglycemia, apnea, hyperventilation, ketosis, and lactic acidosisLethal in newbornsTriggered by fasting or infections in adults

Classic galactosemia

Defect in either galactose-1-phosphate uridyl transferase or galactokinaseVomiting and diarrhea following ingestion of milk; impaired liver functioning may lead to cirrhosis; hypergalactosemia; metabolic acidosis; urinary galactitol excretion and hyperaminoaciduria; can cause blindness and fatal liver damageRestrict galactose form diet

UDP-galactose-4-epimerase deficiency

Type I: benign; affects only RBCs and WBCsType II: affects multiple tissues and manifests symptoms similar to transferase deficiencyRestrict galactose from diet

lactose intolerance

usually due to loss of lactase (beta galactosidase)lactose isn't broken down completely in small intestine and it passes into large where bacteria metabolize it; cramping and flatulence; can also cause water retention in intestine and diarrheaControl diet

Straddle injury

Young boys; rupture urethra fromo urogenital diaphragm and spill either urine or blood into scarpa's fascia

Indirect inguinal hernia

Gut herniates through inguinal canal; bulge fills scrotum; lateral to inferior epigastric artery

Direct inguinal hernia

Usually due to pushing strainDirectly through the wall (inguinal traingle)Bulge does not typically fill scrotumMedial to inferior epigastric artery

Glucose-6-phosphate dehydrogenase deficiency

lack of enzyme so no pentose-phosphate pathway; reduced NADPH with secondary reductionin glutathione (GSH) which is required for RBC membrane and without it, hemolytic loss occurs and anemia resultsAdvantageous when in conjuction with malaria

I-cell disease

GlcNAc phosphotransferase deficiencyDefect in attachment of phosphate group to make mannose-6-phosphate (usually targets protein to the lysosome for degradation)Buildup of proteins causing progressive psychomotor retardation and early death

Branched chain ketoacdiuria "maple syrup urine disease"

Def in branched-chain keto acid dehydrogenase complexVomiting, convulsions and neonatal death; MR in survivors


Def in crystathionine beta synthaseMR, severe eye dxs, osteoporosis and frail bone structure


Def in homogentistic acid oxidaseUrine darkens upon standing, prone to arthritis


Tyrosinase in melanocytes is absentWhite hair, pink skin, no significant pigementation

hartnup's Disease

Defect in intestinal and renal transport and reasorption of neutral AAs (esp tryptophan)Ataxia, occular symptoms, emotional, pellegra like symptoms, nicotinamide (niacin) deficiency

Phenylketonuria (PKU)

Usually a defect in Phe hydroxylaseAbility to converte Phe to tyrosine is inhibitedLight color of skin, eyes, and internal tissues because melanin is made fromo tyrosineDiet low in Phe and total protein for first couple years


fasting or severe dieting; can also occur when DM is not well-controlledHigh levels of ketone bodies in blood is ketonemia (in urine, it's ketonuria)Can be fatal in diabetics

Multiple Sclerosis

Demyelinating disease (loss of phospholipids and sphingolipids from white matter); lipid composition of white resembles thaty of gray; CSF shows high phospholipid levels

Sphingolipidoses (lipid storage diseases)

Genetic defect in catabolism of lipids containing sphingosine; defects in lysosomal degradation pathway of sphingolipidsComplex lipids containing ceramide accumulate in cells (esp neurons) causing neurodegeneration; rate of synthesis of stored lipids is normal thoughSome success with enzyme replacement and bone marrow transplantation


Type of SphingolipidosesDeficit in hexosaminidase ACermide lipid accumulatesNormal development, then nerve cells fill with fat; deterioration; blindness; uanble to swallow due to muscle atrophy; msot die within 5 years

Splenic vein thrombosis

Can result in pancreatitis; presents with abdominal pain; rare

Duodenal ulcers

95% occur in posterior wall of the first portion; remember that the pancreas is back there as well

Oropharyngeal dysphagia

Most commonly caused by stroke; seen in Parkinson's, MS, myasthenia gravis, and end-stage dementiainability of difficulty swallowing; difficulty moving food from front of mouth to posterior oropharynx to esophagus

Esophageal dysphagia

Disordered peristaltic motility of the esophagus; msot commonly caused by achlasia or sclerodermaInability or difficulty swallowing; pt complains of food getting stuck

Obstructive dysphagis

Most commonly caused by strictures, schatzki's ring, or external compression on the esophagus by tumor or vasculatureInability or difficulty swallowing; pt complains of food getting stuck; phsyical obstruction to movement of bolus through esophagusRemove object causing obstruction

Schatzki's ring

Commonly caused by relfuxScar tissue forms bandsDilators are often used to dilate the esophagus and break the rings; may need repeat tretaments due to regrowth


Chronic dx characterized by diffuse fibrosis of the skin and internal organs (esp esophagus)4 times more common in women than men; in 3 to 6th decade


Common in diabetics, hypothyroidism, post-operative, parkinson's, and various infectionsChronicIntermittent n/v, early satiety, bloating and upper abdominal discomfort, gastric reteention of 60% after 2+ hours or 10% after 4 hours; may be caused by autonomic neuropathyPharmacotherapy; avoid opiates; eat small frequent meals; avoid gas


abnormal motor functionDisorder of bowel motilityl may have constipation-predominant or diarrhea-predominant2/3 womenDiagnosis of exclusionAvoid dietary triggers; take anti-diarrheal, anti-constipation, serotonin receptor agonists (increase motility) and antagonists (to decrease motility); depending on what type you have


Persistent, difficult, infrequent, seemingly incomplete defecationWide variability of normal bowel habits makes it difficult to define (<3 bm/week)Eat a fiber-rich dieat, adequate fluid intake, appropriate bowel habits and training, avoid constipating drugs, increase activity, bulk-forming agents, laxatives, and stool softeners

narcotic bowel

Opiate receptors in the bowel significantly slow down motility when activated by reducing response to excitatory NTs causing constipation

Pseudo-obstruction (ileus)

Commonly caused by surgery, infection, inflammation, or medsSigns and symptoms of intestinal bowel obstruction with no mechanical cause; air-filled bowelMost common type is paralytic ileusGive it time/IV fluid/electrolyte replacement; gastric decompression (remove air); may require surgery

Hirschsprung disease

Congenital abnormality of the small bowel caused by incomplete migration of neural crest cells resulting in loss of innervationColon from internal anal sphincter in a proximal direction (of variable length) remains permanently contracted; gut segment proximal to this dilates1/5000 live birthsSurgical correction to remove piece of bowel

Viral gastroenteritis

Cuased by norwalk or rotavirusAcute diarrheaNorwalk is mainly in the winter (24-48 hrs)Rotavirus is mainly in infants and childhood; severe if it penetrates the epithelium

Osmotic diarrhea

Due to ingestion (osmotic laxatives), maldigestion (pancreatic and lactase def), and malabsorption (carb. malabsorption and congenital chloridorrhea)Watery diarrhea, high osmolal gap (>50); if fecal pH<6, due to carb malabsorption; if increased fecal mG, due to laxative abuse

Secretory diarrhea

Caused by bacterial enterotoxins (e.coli and cholerae) and secretagogues (bile acids, FAs, ethanol, carcinoid syndrome, gastrinoma, and calcitonin)Watery diarrhea; when they stop eatch, diarrhea continues

Disorderd motility diarrhea

Due to change in transit timeSlow: fistulas, strictures, and diabetic neuropathyRapid: intestinal resection, IBS, hyperthyroidism, and post-vagotomy


def in Vitamin CRare in US; smoking is risk factorPoor collagen synthesis and wound healing; skeletal changes due to insufficient osteoid matrix

Riboflavin deficiency

Common, but pts rarely seek medical attentionOcular symptoms, frontal headaches, cheliosis, palor at angles of mouth, cracks/fissures, glossitis

Protein-energy malnutiriton (PEM)

either due to inadequate intake of protein (somatic or visceral) or calories to meet the body's needsCommon in underdeveloped countries; can be fatal; in developed countries, seen with poverty, alcoholism, ignorance, acute or chronic illness, and voluntary diet restriction

Marasmus (sub-type of PEM)

def of total food intake (somatic protein compartment)Spindly legs and arms, stunted growth, anemia, infections and defects in immunity, multi-vitamin def, serum albumin normal to slightly reduced

Kwashiorkor (sub-type of PEM)

Def of protein intake (visceral protein compartment)Babies who are weaned early and fed exclusively carb diet; also caused by chronic diarrhea, protein losing enteropathies, and nephrotic syndromeApathy, listlessness, loss of appetite, enlargened fatty liver, hypoalbuminemia, altering zones of hyperpigmentation, stunted growth, anemia, infections and defects in immunity, multi-vitamin deficiencies

Cachexia (sub-type of PEM)

marasmus-like PEM seen in AIDS, cancer, and end-stage lung diseasesDepletion of subcutaneous fat, muscle wasting, and ankle edema

Kwashiorkor-like PEM (subptype of PEM)

usualyl seen with severe trauma, burns, and sepsis

Anorexia nervosa

self-induced starvation, amenorrhea, decreased thyroid hormone release and boen density, anemia, lymphopenia, hypoalbuminemia, cold intolerance, bradycardia, constipation, scaly skin, prone to hypokalemia (increases risk of sudden death)


Binge eating followed by induced vomiting, menstrual irregularities, complications of chronic vomiting, pulmonary aspiration of gastric contents, esophageal and cardiac rupture allowing bacteria into mediastinum, also prone to hypokalemia and sudden death


Excess vit A precursorsYellow-orange skin with white sclera (difference from jaundice)


vit D deficiencypredisposed to fractures, bowed legs, can be mistaken for abuse


thiamine deficiencyDry (toe drop, common in alcoholics, pernicious vomiting during pregnancy, diseases that imapir appetite or cause diarrhea; can cause heart failure due to edema and hemorrhage into mammillary body)Wet (CV problems)

Wernicke-Korsakoff syndrome

thiamine deficiency causing brain problems (encephalopathy)


Niacin deficiency (B3)Dermatitis, diarrhea, dementia--classic picture of hands

Squamous cell carcinoma of the esophagus

smoking and alcohol; poor prognosisl common in males and AAs; geographic distribution (Asia, Africa, S. America)Pt complains of difficulty swallowing, heartburn, wgt loss

Adenocarcinoma of the esophagus

smoking and alcohol; poor prognosis; geographic variation (Asia, Africa, S. America)GERD-->Barrett's esopagus (10-20 times more likely)--occurs in lower esophagusResults from metaplasiaPt complains of difficults swallowing, heartburn, and wgt loss

Barrett esophagus

Intestinal metaplasia of the esophagusNormal linining is squamous; chronic exposure to gastric reflux leads to metaplasia and columnar epithelium; incidence is on the rise

Gastric carcinoma

H. pylori, AI gastritis, metaplasia, food, familial factors, gastric adenoma (benign tumor); more frequent in Asia, E. Europe, Africa, and S. America; decreasing incidencePoor prognosis (early detection helps-Japan)Aysmptomatic until too late, wgt loss, anorexia, abdominal pain, and Krukenburg tumor (of the ovaries--metastasis)Most are adenocarcinoma (diffuse signet ring type)

Gastric adenoma

Benign tumor; premalignant; adjacent gasric mucosa may develop cancer in 30% of cases

Crohn's disease

sub-type of IBDSkip lesions, 80% in small intestion (ileocecal junction), Ash-Jewish, Asian, and AA population; bimodal distTriad of symptoms: diarrhea, ab pain, 10+% wgt loss


bacterial, parasitic, viralPresent with inflammation and diarrheaFluids, electrolytes, and nutrition for treatment

Hyperplastic polyp

non-neoplastic polyp in colonPretty-star shaped growths

Hamartomatous polyp

non-neoplastic polyp of the colonLooks like a stalk of broccoli

Tubular adenoma

Most common polyp (40% of these become malignant)Usually small and predunculated; may be raised (look like broccoli)

Villous adenoma

Les common, and 10 times less likely to become malignant than tubular adenomalarger and sessile with a broader base; may be combined as tubulovillous

FAP (familial adenomatous polyposis)

stepwise accumulation of genetic mutationsPolyps start benign and then become malignantAttentuated: fewer polyps in right colon (secum)Garnder syndrome (FAP + osteomas, fibromas, epidermal cysts)Turcot syndrome: FAP + brain tumors

Colorectal carcinoma

Second in incidence to lung cancer in men and third to breast in womenRarely causes obstruction in right colon, does in left; with right colon, pt presents with microscopic bleeding, anemia (due to depletion in iron due to continuous bleeding); in left colon, pt presents with pencil like feces and constipationAdenocarcinoma is most common in bothCan be asymptomatic for years; colon more common in women and rectal more common in menMetastasis to local LNs, liver, lung (triple L)CEA (carcinoembryonic antigen) is a marker for tumor after surgery, not for primary detection

Carcinoid tumor

NE tumor of the GI tract and resp tract; most common in small intestine; size matters; secrete polypeptide hormones and biogenic amines (5-HT); present with 5-hydroxyindoleacetic acid in urine

Gastrointestinal stromal tumor (GIST)

Express mutated c-KIT and PDGFRAtumor of the GI system composed of stromal cells; benign or malignant; may occur anywhere from stomach to intestines (histologically, it looks like collagen/stroma w/lymphocyte infiltrates)Inhibitors of TK block growth

Gastrointestinal lymphoma

H pylori is a risk factorSecondary spreading to the GI from lymph nodes, primaryily originates in the GI tractGI is most common site of extranodal lymphomaStomach is most common site of GI lymphomasMost are MALTomas (respond well to H pylori therapy)

Acute pancreatitis

alcohol abuse and gall stones (50%)--caused by anything that obstructs the duct, causes acinar cell injury, defective intracellular transportactivation of lipolytic enzymes produces fat necrosis; activation of proteolytic enzymes activates chemotactic factors (inflam and leukocytosis) leading to fever; microvasc leakage leads to edema; endothelial injury leads to thrombosis and hemorrhageEpigastric pain of sudden onset, n/v, low-grade fever, dehydration, tender abdomen, xray shows sentinel loop, US shows gallstones and swelling; elevated amylase and lipase; decreased Ca; get ERCP

Pancreatic Pseudocyst

Complication of acute pancreatitisCyst with necrotic surface and no epithelium

Chronic pancreatitis

more common in men; alcohol abuse causes toxic effects directly to acinar cells and can cause spasms of sphincter of Oddi; caused by repeated bouts of acute pancreatitis and ductal obstructionsPresent with ab pain, calcifications and pseudocysts; pancreatic insufficiencies resulting in malabsorption, diabetes (destruction of islets of Langerhans)Ductal dilation on US; ERCP shows beadingTreat with low fat diet, no alcohol, enzyme supplementation, pain management, surgery to restore bile flow

Hiatal hernia

gastroesophageal junction protrudes through the esophageal hiatus with or without the stomachMimics the substernal pain of an MI but sitting up from supine position lessens the pain here

Esophageal varices

Caused by portal hypertension; small veins in esophagus become dilated; varices/dilation can rupture under stress leading to profuse hemorrhage


Absence of intinsic neurons in lower esophagus (cause or effect?)Dysmotility in lower esophagus causes upper esophagus hypertrophy and dilation; patients have recurrnet vomiting leading to malnutrition


"heartburn" in abdominal part of esophagus


inflammation of the gall bladder; can spread to first part of duodenum with consequent adhesions to or perforating ulcerations of the duodenumPositive murphy's sign

Pancreatic adenocarcinoma

most common tumor of the pancreas; elderly; male predominance in younger, but equal in older; high in USMulitple hits; starts in situ (most in the head); highly invasive and elicits a strong desmoplastic reaction; malignant epithelial cells may secrete/contain mucinAsyptomatic until perineural invasion and pain; painless jaundice, ab pain, wgt loss, anorexia, migratory thrombophlebitis (Troussea sign), anemia, hyperglycemiaSurgical resection (Whipple procedure) is rarely curative; pallitative measures

Portal hypertension

pre-hepatic disease (partial occlusion in portal vein, i.e. hemolytic jaundice); intra-hepatic (cirrhosis, malignant metastases, and hemolytic jaundice); or post-hepatice disease (compression of IVC or obstructive jaundice)Resistance to blood flow through liverHemorrhages, hemorrhoids, and caput medusae


Viral or bacterial liver infection; leads to erosion through dense liver capsule into abdominal cavity or across diaphragm; results in pleuritis or empyema

Biliary colic

blockage in duct; RUQ pain due to distension between waves of contraction in duct


made from bilirubin metabolites, cholesterol, or calcium slatsCan obstruct gall bladder causing bile retention and rupture resulting in peritonitis; can obstruct common bile duct or hepatopancreatic duct (bile is diverted into pancreatic duct); or when gallstones pass through sphincters, make them less competenct to assist in regulating flow of bile and pancreatic enzymes


Twisting of intestines around mesentery; leads to compression and strangulation of blood vessels within mesentery; ischemia and necrosis; most prevalent in large bowel (cecum and sigmoid)

Acute hepatitis

inflammation of the liver or short durationCell injury includes apoptosis and necrosisJaundice, fatigue, nausea, loss of appetite, increased ALT/AST and bilirubin (C+UC)if severe, decreased albumin, increased PT time, increased ammonia=urgent transplant

Chronic hepatitis

VIRAL mneumonic (viral, immunologi, Rx, alcoholic/NASH, library list of genetic diseases)inflammation of the liver for longer than 6 monthsIncreased or decreased AST, ALT, bilirubin, albumin, and PTBiopsy must be performedCan progress to cirrhosis


Viral hep C, alcohol abuse, steatohepatitis (diabetes, obesity, idiopathic), immune (AI, primary biliary cirrhosis, primary sclerosing cholagnitis), genetic (hemochromatosis, Wilson);15% are cryptogenicChronic liver disease with loss of normal architecture, widespread fibrosis, ndoular transformation of parenchyma, portal hypertension, bleeding tendency, hepatic encephalopathyDecreased synthetics; can lead to liver cell carcinoma


hypoalbuminemia, sinusoidal HTN, percolation o fhepatic lymph (blocked), and splenic congestion all cause>500 mL is detectableIf RBCs, think tumor

Hepatic encephalopathy

Shunting of blood by liver results in inadequate detoxification of potentially toxic metabolits by liverConfusion, stupor, coma, increased blood ammonia (>50)

Hepatorenal syndrome

renal failure caused by liver failureOligouria, increased BUN and creatinine, concentrated urine, pt unresponsive to diuretic therapy; jaundice, ascites, urinary failure, neurologic, dyspnea, infections, coagulopathy, endocrine

Hereditary hemochromatosis

asymptomatic until 40-50; iron is stored preferentially in liver; involves liver, skin, heart, endocrine, and jointsPresent with liver disease (cirrhosis), increased iron saturation, increased risk of liver cancerGrossly and histologically, can see accumulations of ironLung problems due to elastase

Alpha1-antitrypsin deficiency

Protein is not allowed to move to from ER to GA for secretion, so A1-AT accumulates in hepatocytes; abnormally low serum levels of it; present with liver diseaseJaundice and symptoms of cholestasis, increased transaminase, hepatocellular carcinoma; lung disease and vasculitis

Subhepatic cecum

lack of descent of the cecum from RUQ to LUQCan be asymptomatic, but increased risk for obstructive event


fecal blockage of the appendix's lumen leading to vascular congestion, ischemia, bacterial growth, infection, perforation of wall with pus released into abdominopelvic cavityInitial pain is dull in umbilical region (referred via lesser thoracic splanchnic to T10) but becomes sharp and localized due to direct irritation of escaping pus to parietal peritoneum of the wall


dvlpt of small blind pouch in colonic wall that become inflammed and can rupture; frequent in older population; no popcorn or nuts as these can cause rupture

Ulcerative colitis

Chronic inflammation and destruction of mucosal lining that manifests as chronic diarrhea and abdominal painNo skip lesions


Inflammation of lymph vessels


inflammation of lymph nodes


15-20% caused by impaired basal tone of LES; rest due to transient LES relaxationChronic symptoms (ie heartburn with or without mucosal damage produced by abnormal reflux of gastric content in esophagus); increased risk of developing esophageal adenocarcinoma

Psoas abscess

due to close interaction with overlying fascia, might impinge on nerve roots causing pain when psoas is contracted; relieve when lifting supine patient legs toward their abdomen

Lateral femoral cutaneous nerve syndrome

compression (ie belt too tight) and endocrine (alcoholism and diabetes) causesMononeuropathy; present with pain, numbness, tingling, burning and itching in anterolateral thigh