CHEAK FA BOOK FOR PHYSIO
ESPISIALLY P 378/379/380 FOR TABLES
VIPoma / WDHA
VIPoma (Pancreatic Cholera)
Type: Pancreatic islet cell tumor secreting VIP
Triad (WDHA syndrome):
Watery diarrhea (>3 L/day, secretory, persists despite fasting)
Dehydration / Hypokalemia
Achlorhydria
Pathophysiology:
VIP → ↑ cAMP in enterocytes → ↑ Na⁺, Cl⁻, H₂O secretion
Also stimulates pancreatic HCO₃⁻ and Cl⁻ secretion
Differentiation:
Not inflammatory (no blood/pus)
Not osmotic (doesn’t improve with fasting/diet change)
Treatment:
Octreotide (somatostatin analog) → ↓ VIP secretion
IV fluids/electrolytes, surgical resection if possible
Vitamin Supplementation
1)) Breast milk = gold standard (proteins, carbs, fats, vitamins, trace minerals, Ig, enzymes).
Deficient in:
Vitamin K → IM at birth (prevent hemorrhagic disease).
Vitamin D → supplement in all exclusively breastfed infants (prevent rickets).
Iron →Preterm / low-birthweight infants: need earlier iron
2)) Vegan diet
Potential nutritional deficiencies
Common: vitamin B12, vitamin D, calcium
Possible*: iron, zinc (children young women ):
3)) B12 DEFICINCY
Vitamin B12 ↓
Methylmalonic acid ↑ (specific for B12 deficiency)
Homocysteine ↑ (also elevated in folate deficiency)
Treatment Response
After starting vitamin B12 replacement:
Reticulocyte count ↑ within 3–4 days, peaks at ~1 week IMPORTANTT
Hemoglobin & RBC count normalize over 6–8 weeks
Source of IF: Parietal cells (body & fundus of stomach).
Function: IF binds vitamin B12 → complex absorbed in terminal ileum.
After Total Gastrectomy: No IF production → severely impaired B12 absorption
Parietal cells (stomach):
H⁺/K⁺ ATPase (proton pump): pumps H⁺ into lumen ↔ K⁺ into cell.
PPIs (eg, omeprazole):
Inhibit H⁺/K⁺ ATPase → ↓ gastric acid secretion.
Clinical uses:
Peptic ulcer disease
GERD
Zollinger–Ellison syndrome (gastrinoma)
Diarrhea
Daily GI fluid load: ~2 L intake + ~7 L secretions → ~9 L total.
Small intestine: reabsorbs most fluid.
Mechanism of Water Absorption
Apical (lumen side) : Na⁺ cotransport with Cl⁻, glucose, or amino acids.
Basolateral (blood side) : Na⁺/K⁺ ATPase pumps Na⁺ out → osmotic gradient pulls H₂O through tight junctions.
Acute Viral Diarrhea (eg, Rotavirus, Norovirus)
Mechanism: ↓ NaCl absorption or ↑ Cl⁻ secretion (via ↑ cAMP, cGMP, Ca²⁺).
Results: Watery diarrhea (non-bloody, no leukocytes).
Treatment:
IMPORTANT
Oral rehydration solution (ORS): hypotonic, equimolar Na⁺ + glucose → enhances Na⁺ & H₂O absorption.
Most effective therapy to maintain volume/electrolyte balance in children with acute diarrhea.
Diabetic diarrhea
Cause: Long-standing hyperglycemia → glycosylation of vasa nervorum → nerve ischemia & damage.
Autonomic Involvement: Damage to sympathetic & parasympathetic nerves → GI dysmotility.
Features:
Watery, secretory-like diarrhea (persists with fasting, including nocturnal diarrhea). IMPOTARTANTT
Fecal incontinence (large-volume diarrhea + ↓ anorectal sensation).
Failure of relaxation in fundus & uncoordinated peristalsis
Labs typically normal (no fecal leukocytes/occult blood).
Other GI Manifestations: Gastroparesis, gastroesophageal reflux.
Clinical presentation
Postprandial bloating & vomiting
Early satiety
Impaired nutrition & weight loss
Diagnosis
Nuclear gastric emptying study: delayed transit into duodenum
Treatment
Promotility drugs: metoclopramide, erythromycin
Swallowing
Protective airway movements:
1)) Larynx moves up & forward (under tongue → directs food into esophagus).
2))Epiglottis tilts → blocks airway.
3))Glottis closes (vocal fold adduction).
Stroke patients:
High risk of dysphagia & aspiration (complex coordination impaired).
Management (if neurologic deficit persists):
Behavioral modifications may help.
Chin-tuck maneuver: important
Flex head/neck during swallow.
larynx elevation (superior displacement).
Narrows laryngeal entrance. → Reduces aspiration risk.
Protein digestion:
Starts: Stomach → Pepsin (activated by HCl).
Major site: Small intestine.
Pancreatic enzymes (secreted inactive):
Trypsin, chymotrypsin, carboxypeptidase, elastase.
Activation cascade: IMPORTANTT
Enteropeptidase (brush border enzyme): trypsinogen → trypsin.
Trypsin → digests proteins & activates other pancreatic proteases + lipase/colipase.
Enteropeptidase deficiency: IMPORTANTT
↓ Trypsin activation → impaired protein and fat digestion.
Clinical signs:
Diarrhea
Failure to thrive
Edema (hypoproteinemia)
Phases of Gastric Acid Secretion
Phases of Gastric Acid Secretion
Cephalic phase
Trigger: Thought, sight, smell, taste of food
Mediator: Vagus nerve (ACh, vagal stimulation)
Effect: ↑ acid secretion
Gastric phase
Trigger: Food in stomach (distension, peptides, amino acids)
Mediator: Gastrin → ↑ histamine (from ECL cells) → ↑ acid
Effect: Major stimulator of acid secretion
3)) Intestinal phase
Trigger: Chyme (esp. protein) in duodenum
Effect: Minor stimulation of acid initially
Main role: Down-regulation of gastric acid secretion after meal
Peptide YY (ileum & colon): inhibits gastrin-induced histamine release from ECL cells
Other inhibitors: Somatostatin, prostaglandins
CHEACK THE PATHOLOGY SECTION FROM THE BOOK
in the flash cards I will highlight only recurrent questions or hidden detail
Hepatitis
in acute :
Viral antigens trigger cytotoxic T lymphocyte response via MCH1.
T cells CD8+ induce hepatocyte apoptosis (virus does not have a cytotoxic effect itself) VERY IMPORTANT
Panlobular lymphocytic inflammation.
Apoptotic hepatocytes = Councilman bodies (acidophil bodies).
in Contrast:
Drug/toxin injury (eg, acetaminophen) → centrilobular necrosis (zone 3), not panlobular apoptosis.
1)) Acute Hepatitis A
IgM anti-HAV → acute infection
IgG anti-HAV → past infection or vaccination
Histology:
Spotty necrosis
Ballooning degeneration (hepatocyte swelling, wispy cytoplasm)
Councilman bodies (eosinophilic apoptotic hepatocytes)
Mononuclear infiltrates (lymphocytes)
Clinical course:
1.Prodrome (1–2 weeks): fever, malaise, anorexia, nausea, vomiting, RUQ pain.
2.Cholestatic phase: jaundice, pruritus, dark urine (↑ conjugated bilirubin), acholic stool.
3.Resolution: illness is self-limited.
Key Point:
No chronic hepatitis, cirrhosis, or hepatocellular carcinoma risk (unlike HBV/HCV).
Transmission: fecal-oral, often associated with travel to endemic areas or contaminated food/water.
2)) HBV
HBsAg
First marker to appear Infection is present (acute or chronic)
Anti-HBs
After clearance or vaccination
HBcAg
(not seen in blood) Detected only in liver tissue
Anti-HBc IgM
Acute infection (window period marker)
Anti-HBc IgG
persists lifelong Indicates prior exposure (chronic or resolved infection)
HBeAg
During active viral replication High infectivity
Anti-HBe
Lower infectivity, improving state
acute hepatitis B infection?
Virus: DNA virus, incubation 30–180 days.
Transmission: Sexual, parenteral, vertical.
Clinical features:
Serum sickness-like prodrome: fever, rash (pruritic urticarial vasculitis), arthralgias, lymphadenopathy.
Right upper quadrant pain, hepatomegaly.
↑ AST & ALT (>10× normal), ± jaundice.
Prolonged PT = poor prognosis.
Chronic infection hallmark: Ground-glass hepatocytes
Finely granular, homogeneous, pale eosinophilic cytoplasm (due to HBsAg accumulation)
3)) HCV
Anti-HCV antibody → exposure (past or current)
HCV RNA (PCR) → active infection (needed to confirm)
Histology
Acute HCV:
Panlobular lymphocytic inflammation
Ballooning degeneration (hepatocyte swelling/injury)
Councilman bodies (apoptotic hepatocytes)
Chronic HCV:
Portal lymphocytic infiltration
Lymphoid follicle formation
Fibrosis (progressive)
Cirrhosis (end-stage):
Extensive fibrosis
Acute hepatitis C is typically asymptomatic; dermatologic manifestations (eg, cryoglobulinemia) are seen in chronic infection.
Alcoholic hepatitis
Pathophysiology
Heavy ethanol consumption → intrahepatic oxidative damage → recruitment of neutrophils to the liver
Symptoms
Fever
Right upper quadrant pain
Jaundice
Histology
IMPORTANTT
Marked intrahepatic neutrophilic infiltration
Hepatocellular ballooning
Mallory-Denk bodies
Steatosis
Laboratory studies
Aminotransferase elevations with AST/ALT ratio >2:1
Direct hyperbilirubinemia
Leukocytosis
PT & PTT elevations
Alcohol‑related hepatic steatosis
Definition: Reversible accumulation of triglycerides within hepatocyte cytoplasm following recent or chronic ethanol exposure.
Rapid recall: “Ethanol → ↑ NADH/NAD+ → ↓ FFA oxidation + ↑ lipogenesis + ↑ glycerol‑3‑P → hepatocyte TG accumulation.”
Pathology clue: Macrovesicular steatosis on biopsy; potentially reversible with alcohol cessation.
Chronic Cholestatic Diseases
Primary biliary cholangitis (PBC) / Primary sclerosing cholangitis (PSC):
Present with prolonged pruritus + fatigue.
Progress to acholic stools, fat-soluble vitamin deficiency (esp. Vit D), → metabolic bone disease (osteoporosis/osteomalacia).
Chronic progressive → risk of cirrhosis, cholangiocarcinoma.
can cause malabsorption and nutritional deficiencies of fat-soluble vitamins.
Whipple Disease
Bacteria ingested → engulfed by macrophages.
Accumulation of foamy macrophages → lymphatic obstruction → malabsorption.
Clinical Triad
GI: Diarrhea, steatorrhea, weight loss, abdominal pain.
Arthralgia (migratory).
Systemic spread: CNS (dementia, ophthalmoplegia), heart (endocarditis).
PAS-positive macrophages in lamina propria IMPORTANTT
TX: Long-term (ie, ≥12 months) antibiotic therapy is usually successful in resolving the symptoms, although relapses can occur.
Peptic Ulcers
1)) Duodenal ulcers MOST COMMON SITE
95% in 1st part of duodenum. (note: its intraperitoneal and the rest of duodenal is retro )
Rarely malignant → no biopsy needed.
H. pylori–related but no increased risk of duodenal carcinoma.
VERY IMPORTANT::
Posterior duodenal ulcers erode the GASTODUODENAL A. (massive GI bleeding).
Anterior duodenal ulcers are more likely to perforate into the peritoneum (peritonitis).
2)) Gastric ulcers
May be malignant → must biopsy.
H. pylori–associated ↑ risk of gastric adenocarcinoma.
MC Location: Lesser curvature of the stomach at the transitional zone between the corpus (body) and antrum.
Cell types:
Corpus: Parietal cells → hydrochloric acid + intrinsic factor.
Antrum: G cells → gastrin.
Pathogenesis: Optimal environment for H. pylori → chronic inflammation → mucosal atrophy → ulcer formation.
Hemorrhage risk: Left and right gastric arteries run along the lesser curvature → common source of bleeding from penetrating ulcers. IMPORTANTTTT
Other complications: Penetration into adjacent organs (biliary tract, colon), gastric outlet obstruction, free wall perforation with peritonitis.
3)) Refractory or distal duodenal ulcers → think gastrinoma (Zollinger-Ellison syndrome).
Antral gastritis → duodenal ulcers
Gallstones (Cholelithiasis)
gallstone formation
↑ Cholesterol in bile risk of cholesterol gallstones.
↓ Bile salts & ↓ phosphatidylcholin
↑ risk of cholesterol gallstones.
Types
1))Cholesterol stones (most common in U.S.)
Yellow, radiolucent (unless mixed with Ca²⁺).
Risk factors: Obesity, metabolic syndrome, multiparity, oral contraceptives, rapid weight loss, Native American ethnicity.
Crohn Disease (Terminal Ileum):
Inflammation → bile acid loss in feces.
↓ Bile acids in bile → ↑ cholesterol/bile acid ratio → supersaturation.
Result: Cholesterol gallstone formation
2)) Pigment stones (10–25% U.S.; more common in Asia).
Brown stones:
Cause: Biliary tract infections (bacteria/helminths produce β-glucuronidase).
Soft, greasy.
Black stones:
Cause: Chronic hemolysis (eg, sickle cell, thalassemia, hereditary spherocytosis), ileal disease (↑ enterohepatic cycling).
Small, numerous, spiculated, friable.
High Ca²⁺ content → radiopaque (seen on x-ray).
Beta-glucuronidase released by injured hepatocytes and bacteria hydrolyzes bilirubin glucuronides to unconjugated bilirubin
✅ High-yield pearls:
Brown stones = infection.
Black stones = hemolysis / ↑ bilirubin cycling.
Cholesterol stones = obesity, estrogen, weight changes
can cause malabsorption and nutritional deficiencies of fat-soluble vitamins.
Pathophysiology:
Gallbladder hypomotility → impaired emptying → bile becomes concentrated
Active water absorption by gallbladder → bile dehydration → precipitation of:
Cholesterol monohydrate crystals
Calcium bilirubinate
Mucus
Formation of viscous biliary sludge IMPORTANTT
Clinical Features:
Often asymptomatic
Can cause biliary colic (RUQ pain + nausea)
May progress to cholesterol stones
Nonvisualization of the gallbladder on HIDA scan despite visualization of the biliary tree and small bowel = cystic duct obstruction (acute cholecystitis).
EVEN THOUGH The presence of echogenic structures within the gallbladder on ultrasound can be suggestive of acute cholecystitis in the setting of fever and abdominal pain, but it is not diagnostic. Cholelithiasis can also cause more benign biliary colic, or be an incidental asymptomatic finding in the setting of other abdominal pathology. Ultrasound findings more specific for acute cholecystitis include gallbladder wall thickening, pericholecystic fluid, and a positive sonographic Murphy sign.
Pancreatic Neuroendocrine Tumors (PanNETs)
Origin: Pancreatic islet cells.
Immunohistochemistry : IMPORTANTTTT
Synaptophysin → neuroendocrine synaptic vesicles.
Chromogranin A → secretory granules.
Positive staining confirms neuroendocrine origin
Types:
1)) Functional → secrete hormones, cause clinical syndromes:
Insulinoma
Gastrinoma (Zollinger-Ellison)
Glucagonoma (necrolytic migratory erythema, diabetes, weight loss)
VIPoma (→ WDHA)
2)) Nonfunctional → no hormone excess; present due to mass effect (epigastric pain, weight loss, jaundice, palpable mass).
Histology
Well-circumscribed tumor.
Organoid architecture: nested, glandular, ribbon, pseudorosette.
Uniform round nuclei with salt-and-pepper chromatin.
Granular cytoplasm.
.
Liver TUMORS
1)) LIVER Metastases
Most common liver neoplasm = metastatic tumors, not primary hepatocellular carcinoma.
Why the liver is prone to metastasis
1.Fenestrated hepatic sinusoidal endothelium → easy entry of tumor cells into parenchyma.
2.Dual blood supply (portal + systemic) → ↑ chance of circulating tumor deposition.
Common Primary Sources
Colorectal cancer (most common, via portal venous spread).
Gastric cancer.
Pancreatic cancer.
Other: breast, lung.
contrast-enhanced CT scan shows multiple hypodense masses in the liver consistent with metastatic liver disease
2)) HCC
Aflatoxin B1 → p53 mutation → HCC
Produced by Aspergillus BY
Contaminates food: corn, peanuts, grains
Grows in hot, humid climates
Alpha-fetoprotein is a serum tumor marker that is often moderately elevated in patients with chronic viral hepatitis. However, it can be strikingly elevated in those with HCC
3)) hepatic angiosarcoma
vinyl chloride ,arsenic
IBD
UC :
Toxic megacolon is a well-recognized complication of ulcerative colitis.
Patients typically present with abdominal pain/distension, bloody diarrhea, fever, and signs of shock.
Plain abdominal x-ray is the preferred diagnostic imaging study.
Barium contrast studies and colonoscopy are contraindicated due to the risk of perforation.
Th2 cells are involved in the pathogenesis of ulcerative colitis. They produce IL-5 and IL-13, which contribute to inflammation and damage of the intestinal mucosa.
CRONS:
Th1 and macrophage activation in response to a difficult-to-eradicate antigen.
Granulomas are characterized by a large number of epithelioid macrophages that may fuse together to form multinucleated cells (Langhans giant cells) surrounded by a band of lymphocytes
strictures (due to bowel wall edema, fibrosis, and thickening of the muscularis mucosae IMPORTANT), fistulas (due to penetration of ulcers through the intestinal wall), and abscesses.
Crohn disease is associated with oxalate kidney stones.
Impaired bile acid absorption in the terminal ileum leads to loss of bile acids in feces with subsequent fat malabsorption. Intestinal lipids then bind calcium ions, and the resulting soap complex is excreted. Free oxalate (normally bound by calcium to form an unabsorbable complex) is absorbed and forms urinary calculi (enteric oxaluria).
IL-10 inhibits proinflammatory cytokines from monocytes/macrophages and dendritic cells (eg, IL-1β, IL-6, IL-12, TNF-α) and suppresses chemokines that recruit effector cells, shutting down inflammatory cascades. It downregulates antigen presentation by reducing MHC class II and co-stimulatory molecules on antigen-presenting cells, and directly limits T-cell IL-2 and IFN-γ production and proliferation
LFT
↑ ALP + ↑ GGT → hepatobiliary origin
↑ ALP + normal GGT → bone origin
CRC
Most important prognostic factor: Tumor stage (invasion/spread) NOT GRADE
Early stage (best prognosis): confined to mucosa (lamina propria, basement membrane)
Progression:
Invades submucosa → muscularis propria
Regional lymph nodes involvement
Distant metastasis (eg, liver, lung) → worst prognosis
CEA :
CEA is NOT a screening or diagnostic tool for colon cancer.
CEA is most useful for follow-up:
Detecting residual disease after surgery
Early identification of recurrence
Adenomatous and sessile serrated polyps are neoplastic polyps that have malignant potential. Increasing polyp size is the most important risk factor for cancer; villous histology and high-grade dysplasia are additional risk factors.
Hundreds–thousands of polyps
Autosomal dominant inheritance
Nearly 100% colorectal cancer risk IMPORTANT
Esophageal SCC vs Adenocarcinoma
🔹 Squamous Cell Carcinoma (SCC):
Histology:
Flattened polyhedral/ovoid epithelial cells
Eosinophilic cytoplasm
Keratin pearls / nests
Intercellular bridges
Location: Upper & middle esophagus
Risk factors: Alcohol, smoking, achalasia, caustic injury, Plummer-Vinson
🔹 Adenocarcinoma (ADC):
Histology:
Glandular cells forming mucin-producing glands
Infiltrating columnar epithelium with intestinal-type differentiation
Location: Distal esophagus (near GE junction)
Risk factors: Barrett esophagus (from GERD), obesity, smoking
Food Protein–Induced Allergic Proctocolitis (FPIAP)
Pathophysiology
Non–IgE-mediated hypersensitivity
Eosinophilic inflammation of rectosigmoid colon
Triggers: cow’s milk, soy protein (in formula or breast milk)
Clinical Features
Age: 1–4 weeks (up to 6 months)
Well-appearing infant (no systemic illness)
Painless, blood- and/or mucus-streaked stools (Hemoccult +)
Treatment & Prognosis
Remove trigger protein:
Hydrolyzed formula (if formula-fed)
Maternal elimination of dairy/soy (if breastfed)
Symptoms resolve in 1–2 weeks
Tolerance by age 1 in most infants
