GI Pathology Flashcards
Failure of facial prominences to fuse, there are 5 facial prominences , the maxillary and medial nasal fail to fuse
Cleft lip and palate
Painful superficial ulceration of oral mucosa that arises with stress and resolves spontaneously it is characterised by greyish based surrounded by erythema
APTHOUS ULCER
Recurrent apthous ulcers, genital ulcers and uveitis (triad) which happens due to immune complex vasculitis involving small vessels
Behcet syndrome
Primary infection occurs in childhood causing shallow painful red ulcers
herpes simplex virus 1 - oral herpes
After primary infection with HSV1 what happens to the virus?
Stays dormant in the ganglia of trigeminal nerve
What reactivates dormant HSV1?
Stress and sunlight cause reactivation leading to vesicles on lips (COLD SORES)
Malignant neoplasm of squamous cells lining mucosa
Squamous cell carcinoma
What are the major Risk factors of squamous cell carcinoma?
Tobacco smoke and alcohol
What is the most common location of squamous cell carcinoma?
Floor of the mouth is the most common location
What are leukoplakia and erythroplakia?
Precursor lesions of squamous cell carcinoma, they need to be biopsied to rule out the carcinoma.
What can be confused with leukoplakia?
Oral candidiasis a white patch on the mouth which can be easily scrapped
A patch on the lateral tongue due to EBV in immuno compromised
Hairy leukoplakia
What does a true leukoplakia present with
True leukoplakia is presented with hyperplasia
Leukoplakia + blood vessels which indicate angiogenesis
Erythroplakia
Is leukoplakia or erythroplakia more likely to have dysplasia
Erythroplakia
Presents with bilateral inflamed parotid glands can also cause orchitis, pancreatitis and aseptic meningitis
Mumps
Orchitis has a risk of sterility in teens
Pancreatitis + inflamed parotid glands cause increase in serum amylase
A stone obstruction in salivary glands is called
Sialolithiasis
Inflammation of salivary glands due to an obstructing stone (sialolithiasis) leading to S. Aureus infection
Sialadenitis - usually unilateral
- Benign tumour composed of stromal and epithelial tissue which usually arises in the parotid.
- mobile painless circumscribed mass at angle of the jaw
- no invasion of facial nerve
- has high risk of reoccurring due to irregular borders
Pleomorphic adenoma
Most common tumour of salivary glands
Pleomorphic adenoma
When a tumour has for example - stromal (eg.cartilage) and epithelial tissue(eg glands) what is it called?
biphasic two types of tissue
How often does pleomorphic adenoma become carcinoma and what is an indication?
It rarely does and damage to (facial nerve)CN VII ~palsy is the indicator
Benign cystic Timor with abundant lymphocytes with lymph node tissue and germinal centres that almost always happens in parotid glands
Warthin tumour
What the second most common salivary gland tumour that is common for smokers
Warthin tumour
Malignant tumour composed of MUCINOUS AND SQUAMOUS CELLS, that usually arise in parotid commonly INVOLVED FACIAL NERVE - that usually reoccurs
Mucoepidermoid carcinoma
A congenital defect presents in new born as 4 issues •vomiting •polyhydraminous •abdominal distension •aspiration
Tracheoesophageal fistula
Mucosa protrudes in to the lumen causing dysphasia and increased risk for oesophageal squamous cell carcinoma
•seen in Plummer Vinson syndrome with severe Fe deficiency and beefy red tongue
ESOPHAGEAL WEB
- A false esophageal diverticulum of the mucosa and the muscular wall
- arises above the upper esophageal sphincter at junction of esophageal and pharynx
- presents with dysphagia and halitosis (bad breath due to food trapping and rotting)
Zenker diverticulum
- longitudinal laceration of mucosa at gastro esophageal junction which is due to increased vomiting caused by bulimia and alcoholism
- presents with painful hematemesis
- risk of boerhaave syndrome (rupture of esophagus)
Mallory-Weiss syndrome
- Dilated submucosal vein in lower esophagus which arises secondary due to portal HTN
- risk of rupture cuasing painless hematemisis
Esophageal varices
Most common cause of death from liver cirrhosis
Esophageal varices - the veins will rupture and the cirrhotic liver has couagulopathy so can’t close the bleeding
Reflex of acid from stomach due to reduced tone of lower esophageal sphincter
GERD
Risk factors of GERD
Alcohol, tobacco, obesity, fat rich diet, caffeine and hiatal hernia
How can hiatal hernia cause GERD
The diaphragm is important in maintaining the lower esopageal sphincter tone, so in diaphragmatic hernia the stomach can herniate in to the thorax and most common type is sliding hiatal hernia the stomac wil S herniate in to the esophagus and allowing for reflux and giving the hour glass appearance
Patient presents with heartburn (mimics cardiac chest pain) adult onset asthma and cough and damage to enamel teeth ulceration and meta plasma causing Barrett esophagus
GERD
Esophageal metaplasia from squamous cells to non ciliated Columnar epithelium with goblet cells
Butters esophagus
Type is esophageal carcinoma
Adenocarcinoma and squamous cell carcinoma
Most common esophageal carcinoma in the west occurs from metaplasia of burret esophagus occurring at the lower 1/3 of esophagus
Adenocarcinoma
- Malignant proliferation of squamous cells
- most common esophageal cancer world wide and arises in the top 2/3 of the oesophagus due to irritation (eg hot tea, alcohol, tobacco, achalasia)
Squamous cell carcinoma
•Can’t relax lower esophageal sphincter and disordered motility leading to dysphagia and dilation due to food building up
• bird beak esophagus
•caused by ganglion cells damage of the mycenteric plexus
Cells damaged idiopathic or by chagas
•dysphagia, bad breath, LES pressure increase and increased risk of squamous cell carcinoma due to rotting food irritation of wall
Achalasia
Lymph node cancer spread in 3 quarters of the esophagus
Upper 1/3 -> cervical nodes
Middle1/3-> mediastinal and tracheobronchial nodes
Lower 1/3 -> gastric and celiac nodes
A congenital malformation of the abdominal wall leads to exposure of the abdominal content
“A hole in the abdominal wall”
Gastroschisis
A congenital malformations - Persistent herniation of bowel in to the umbilical cord due to failure of herniated intestines to return to body cavity during development
• content are covered by peritoneum and amnion of umbilical cord
Omphalacele
Congenital defects that develops after 2 weeks after birth~ it causes projectile non bilious vomiting as good can’t pass through the stenosis so it shoots back
• visible peristalsis with olive like mass in the abdomen
•hypertrophy of smooth muscle
Pyloric stenosis
Acid damage to mucosa due to imbalance between acidic environment and mucosal defences
Acute gastritis
Epithelial foveolar cells protect by producing - mucosa , increase HCO3- secretion and normal blood supply (absorbing acid and supply nutrients)
Mucosal defended
Severe burn causing an ulcer due to hypovolemia less blood flow to the stomach and decreased nutrient supply and acid sweeping
Curling ulcer
Risk factors of stomach ulcers
NSAIDs chemotherapy Heave alcohol consumption Shock causes stress ulcers Severe burns (curling ulcer) Increased intracranial pressure (Cushing ulcer)
Incrwases intra cranial pressure leads to Increases vagal stimulation -> ach release which binds to parietal cells to secrete 1) achR 2) gastrin r 3) his r Leading to increased acid
Cushing ulcer
Acid damage to stomach results in
Superficial inflammation
Erosion (loss of epithelium)
Ulcer (loss of mucosal layer)
Chronic inflammation of stomach mucosa
Chronic gastritis
types of Chronic gastritis
AutoImmune type and Hpylori type
- T cell mediated autoimmune destruction of gastric parietal cells of the body and fundus
- associated with antibodies against parietal cell and or internsic factor -> used for diagnosis
Chronic autoimmune gasteritis
Clinical features includ •Atrophy of mucosa, •acholhydria due to decreased in number of parietal cells with increase in gastrin level and •Antral G cell hyperplasia • megaloblastic anemia
Chronic autoimmune gastritis #1 cause of bit B12 deficiency
Usually in the stomach there is no inflammatory cells but in chronic gastritis there will be inducing metaplasia which causes
An increased risk for gastric adenocarcinoma
It can induce acute and chronic inflammation of the stomach and is the most common cause 90% of gastritis
Chronic H pylori gastritis
How does H pylori work
H pylori ureases and proteases and it weakens mucosal defenses
Most common site of H pylori and how does it present
Antrum, epigastric abdminal pain with increased risk of ulceration, gastric adenocarcinoma and MALT lymphoma due to intestinal metaplasia
H Pylori treatment and complications
Triple treatment = triple complications
Ulcers , malt lymphoma and adenocarcinoma
How does treatment of h pylori help
Resolves the gastritis which in turn resolves the ulcer and reverses the intestinal metaplasia
How to test h pylori has been resolved
Negative urea Breath test and lack of stool antigen confirm eradication of H pylori
Solitary mucosal ulcer involving proximal duodenum 90% or distal stomach 10%
Peptic ulcer disease
What causes duodenal ulcer
H pylori mostly and early it’s due to ZE syndrome
Presents with epigastirc pain improving with meals and diagnostic endoscopic biopsy shows ulcer with hypertrophy of Brunner glands
Duodenal ulcer
What can an ulcer of the posterior wall of the duodenum do?
It can cause the wall to rupture leading to bleeding from gastroduodenal artery or acute pancreatitis
Causes of gastric ulcers
H pylori 70%
NSAIDS 20%
Bile reflux
Presents with epigastric pain and worsening with meals
Gastric ulcers
What’s the risk of gastric ulcer being on the lesser curvature of antrum
Rupture carries risk of bleeding from the left gastric artery
Differential diagnosis for ulcers includes cancer
•Duodenal ulcers are almost never malignant
•gastric ulcer due to PVD, small punched out and normal surrounding tissue (benign)
Gastric ulcer due to cancer irregular, larger and piling up of mucosa
Malignant proliferation of surface epithelial cells adenocarcinoma can be intestinal or diffuse type
Gastric carcinoma
Which type of gastric carcinoma presents with
• large irregular ulcers with heaped yo margins
• most commonly involves the lesser curvature of antrum (same place as gastric ulcer)
• risk factors intestinal metaplasia due to autoimmune and H pylori chronic gastritis
Intestinal type
Which type of gastric carcinoma presents with
•singer ring cells ( a cell nucleus pushed off due to mucus accumulation) that diffusely infiltrate gastric wall.
• due to the infiltration the gastric wall will undergo desmoplasia white fibrous formation (linitis pastica)
(Not associated with H pylori intestinal metaplasia or nitrosamines
Diffuse type
When do gastric carcinomas present
Late
What do gastric carcinomas present with
- Weight, loss abdominal pain and anemia
- Presents with acanthodians nigricans (dark skin on axilla) and lesser trelat sign (sebbrhoic keratosis over skin
- spreads to vie how’s node
Where does diffuse gastric carcinoma metastasis to
To the ovaries krukenberg tumour
Where does intestinal gastric carcinoma metastasis to
Periumbilical region ( sister Mary joseph nodule)
Gastric carcinoma usually distant metastasis to
Liver
Congenital failure of small bowel to canalize and is associated with down syndrome
Duodenal atresia
Congenital defect that presents with
•polyhydroamnios (can’t digest the ammniotic fluid)
•bilious vomiting (unlike pyloric stenosis with non bilious vomiting)
• distension of stomach and blind loop of duodenum (double bubble sign)
Duodenal atresia
A true diverticulum (zenker is false)
•out pouching if all 3 layers of bowel wall
Arises due to failure if vitelline duct to involute
-rule of 2s->
-2% of pollution
-2inches long
- 2 feet from iliorectal junction
- seen in first 2 years of life
• present with bleeding volvulus and intussusception
Meckel diverticulum
Twisting of bowel along its mesentery
• results in obstruction and disruption of blood supply (infarction)
•most common locations are sigmoid and cecum
Volvulus
Telescoping of proximal segment of bowls in to the distal segment, presents with infarction and obstruction ( currant jelly stool)
Intussusception
Happens due to a leading edge since it moves with the direction of peristalsis there is something it is hooking on
•in children -> most commonly cause is lymphoid hyperplasia
• in adults-> most common cause is tumour
Intussusception
- Transmural infarction occurs with embolism/ thrombosis of superior mesenteric artery or thrombosis of mesenteric vein
- presents with abdominal pain and bloody diarrhoea and decreased bowel sounds
Small bowel infarction
Happens due to not complete obstruction of the arterial supply usually due to hypotension
Mucosal infarction
Immune mediated damage of small bowel villi due to gluten exposure
Celiac disease
Genes associated with celiac disease
HLA DQ2 and HLA DQ8
What is the most pathological component of gluten and how does it affect the bowel
Gliadin - it gets deamidated by tissue trans glutamase
The deamination gliadin is presented by APCs via MHC 2 -> helper T cell mediated damage
What symptoms does celiac disease cause
Bloating and diarrhoea and is associated with dermatitis hepetiformis -> due to IgA deposition at top if dermal papillae resolves with gluten free diet
Lab finding of celiac disease
IgA antibodies against endomysium + TG or gliadin
IgG antibodies are useful in IgA deficiency
What is found on celiac disease biopsy
Flattening of villi hyperplasia of crypts and increased intraepithelial lymphocytes
Damage is mostly in duodenum less in ileum and jejunum
The symptoms resolve with gluten free diet
What are the complications of celiac disease even with a gluten free diet
Small bowel carcinoma and T cell lymphoma
Damage to small bowel villi due to unknown organism results in malabsorption
Similar to celiac disease except ->
•occurs in tropical regions
• arises after infectious diarrhoea and responds to antibiotics
• damage is mostly in jejunum (folic acid def) and ileum (vit B12 Def)
Tropical sprue
•Decrease function of lactase in brush border enterocytes
•Abdominal distension
• diarrhea after milk
- continental (rare) or acquired just by aging or after a GI infection
Lactose intolerance
•Systemic damage, macrophages containing tropheryma whippli
• PAS positive macrophages
• location is small vowel lamina propria
- macrophages compress lacteals
- chylimicrons cannot be transferred from enterocytes to lymphatics
- results in fat malabsorption and steatorrhea
Whipple disease
- Acute inflammation of the appendix, most common cause of acute abdomen
- related to obstruction of the appendix by lymphoid hyperplasia (children) or fecalith(adults)
Acute appendicitis
This disease is presented by peri umbilical pain, fever and nausea.
Pain localises to the RLQ the rupture results in peritonitis with guarding and rebound tenderness
Acute appendicitis
What is the most common tumour of the appendix
Carcinoid tumour
How does cancer of the appendix present
The clinical presentation of adenocarcinoma can be indistinguishable from that of acute appendicitis
Chronic relapsing inflammation of bowel
Possibly due to an abnormal immune response to the enteric flora
IBD
Clinical presentation young women teens to 30s with recurrent bouts of bloody diarrheas and abdominal pain
Irritable bowel disease which is of two type
Ulcerative colitis and chrohn’s disease
IBD with wall involvement and location of
•mucosal and submucosal ulcers
• starts at rectum and can go up to cecum with continued lesions
Ulcerative colitis
IBD That has the wall involvement and location
•full thickness inflammation with knife like fissures
•any where from mouth to the anus presents with skip lesions most common in terminal ileum and least common is the rectum
Chron’s disease
IBD that is accociatwd with
P ANCA and primary sclerosing cholangitis
Ulcerative colitis
Effect of smoking on ulcerative colitis
Protects against ulcerative colitis
IBD associated with ankylosing spolynditis and sarcolitis and uveitis
Chrohns disease
IBD that has a gross appearance of
- cobblestone mucosa creeping far and strictures
- string sign in imaging
Chrohns disease
IBD with symptoms of
•RLQ. Pain (ileum) with non bloody diarrhoea
Chrohns disease
IBD that has inflammation as
•lymphoid aggregates with granulomas
Chrohns disease
IBD with complications of
• malabsorption, calcium oxylate stones fistulas and carcinoma
Chrohns disease
Smoking and chrohns disease
Increases the risk of chrohns disease
IBD with complications that include
• toxic megacolon and carcinoma
Ulcerative colitis
IBD that has a gross appearance of
•pseudopolyps, loss of haustra and lead pipe on imaging
Ulcerative colitis
IBD with inflammation of
•crypt abscesses with neutrophils
Ulcerative colitis
IBD that has symptoms of
•left Lower quadrant pain(rectum) with bloody diarrhea
Ulcerative colitis
- Defective relaxation and peristalsis of rectum and distal sigmoid colon
- associated with down syndrome
- it happens due to ganglion cells fail to descend lacking both ganglion cells from myenteric and meissner plexus.
Hirschsprung disease
Clinical features of this disease are fully based on obstruction
The failure to pass muconium
Massive dilation of bowel proximal to obstruction with risk of rupture
Hirschsprung disease
Which type of biopsy is used for hirschsprung disease
Rectal suction biopsy (pulley the submucosa) it reveals the lack of ganglion cells
What is the treatment of hirschsprung disease
Resection of the area lacking ganglion cells
False diverticulum of the colon (pseudodiverticulum)
• out pouching of mucosa and submucosa through the muscularis propria
Colonic diverticula
What causes colonic diverticula
It is related to wall stress associated with constipation, low fiber diets and commonly seen in older adults
Where does colonic diverticula arise from
Arises from the vasa texts traverse muscularis propria(weak point in the colonic wall)
What is the most common location of the colonic diverticula
Sigmoid is the most common location
Complications of colonic diverticula
- Rectal bleeding - it occurs right up on the wall of the vein so it won’t be hard for bleeding to occur
- Diverticulitis - inflammation of the wall due to blocking of the diverticulum with fecal mater (left sided appendicitis)
- Fistula due to the inflammation of the wall it can rupture and link to another tube
Acquired malformation of mucosa and submucosal capillary beds
Usually arises in cecum and right colon due to increased wall tension
Angio dysplasia
High stress in the left colon -> diverticula
Which lead to
Hematochezia
High stress on the right colon -> angio dysplasia which lead to
Hematochezia in older adults
- Ischemic damage to the colon usually to the splenic flexure
- Atherosclerosis to the superior mesenteric artery is the most common cause
- Presents as postprandial pain and weight loss
- infarctionresults in pain and bloody diarrhoea
Ischemic colitis
- Relapsing abdominal pain with bloating, flatulence and change in the bowel habits (diarrhea and constipation)
- improves with defection
- classically seen in middle aged females
IBS (IRRITABLE BOWEL SYNDROME)
Raised protrusion of colonic mucosa with the most common types being
•hyperplastic
•adenomatous
Colonic polyps
It is the most comon type of colonic polyps happens due to hyperplasia of glands has serrated appearance (saw tooth) on microscopy
•usually arises in the left colon (rectosigmoid)
• benign no malignant potential
Hyperplastic polyp
2nd most common type of colonic polyps it is a neoplasticism proliferation of glands
•benign but pre malignant as it may progress to adenocarcinoma via the adeno carnioma sequence
Adenomatous polyps
What is the adenoma-carcinoma sequence
- APC mutation causes risk of polyp (both copies need to be knocked out)
- KRAS mutation allows for polyp formation
- P53 induces malignancy (increased cox so aspirin protects)
How to screen for polyps
Colonoscopy and testing for fecal occult blood
What is the goal of screening for polyps
Goal is to remove adenomatous polyps before progression to carcinoma
(In colonoscopy all polyps are removed and examined microscopically )
What increases the risk of a polyp to go from adenoma to carcinoma
Polio >2CM
Sessile polyp
Villous histology
- Autosomal dominant disorder charchtarized by 100s to 1000s of adenomatous colonic polyps
- Due to inherited APC mutation
- the colon and rectum are removed prophylactically
Familial adenomatous polyposis
A syndrome which consists of Familial adenomatous polyposis and osteomas with fibromatosis
Gardner syndrome
A syndrome of which a person has Familial adenomatous polyposis and with CNS tumours
Turcot syndrome
Sporadic hamartoma (benign) polyp arising in children <5years Usually solitary rectal polyp-> prolapses and bleeds
Juvenile polyp
- Multiple juvenile polyps in stomach
* only with a large number of juvenile polyps is there an increased risk progression to carcinoma
Juvenile polyposis
- Hamartomatous polyps throughout the GI tract
- Mucocutaneous hyperpigmentation on lips, oral mucosa and genital skin
- increased risk of colorectal cancer breast and GYN cancer
Peutz-jeghers syndrome
Carcinoma arising from colonic or rectal mucosa (peak incidence is 60-70 years)
Colorectal carcinoma
Most common pathway for colorectal carcinoma (80%)
Adenoma carcinoma sequence
2nd most common pathway for colorectal carcinoma
MSI micro satellite instability
Inherited mutation in DNA mismatch repair enzymes
•increased risk for colorectal, ovarian and endometrial carcinoma
•colorectal carcinoma that arises de novo(no history of polyps) at early age
HNPCC hereditary non polyposis colorectal carcinoma
Serum tumour marker for colorectal carcinoma
CEA - not useful for screening but usful to asses treatment and detecting reoccurrence
Screening for colorectal carcinoma
Begins at the age of 50
Colonoscopy and fecal occult blood
