1P-GIT Flashcards
Failure of organ dev’t
AGENESIS
*d/t absence of primordial cells
Arrest in development or maldevelopment
Sx: regurgitation during feeding
ATRESIA
Partial/ complete obstruction d/t fibrous thickening or scarring
STENOSIS
Most common type of esophageal atresia
Proximal end: blunted
Distal end: fistula with trachea
Defect in diaphragm: abd. viscera herniate to thoracic cavity
*CXR: gas bubbles
DIAPHRAGMATIC HERNIA
Abdominal musculature defect; organs protrude thru umbilical cord opening
OMPHALOCELE
*membranous sac present
Defect in all layers of abd. wall; organs are outside the peritoneal cavity, usually to the right of UC.
GASTROSCHISIS
Heterotopic gastric mucosa: facts
- circular, flat, orange to red area
- MC site: Postcricoid region or upper 3rd of esoph. –> - aka: inlet patch
- usually asymp; may produce dysphagia
Heterotopic pancreatic tissue (pancreatic
acinar metaplasia) factors:
- congenital
others: - advancing age - Helicobacter pylori infection - female gender - GERD
MECKEL DIVERTICULUM’s rule of 2s
○ 2x more common in males ○ 2% of the population ○ 2 feet of the ileocecal valve ○ 2 inches in length ○ 2 types of mucosa ○ Presentation before the age of 2
MECKEL DIVERTICULUM’s results from the failed involution of the ___?
Vitelline duct or Omphalomesenteric duct
Assoc. risk factor of PYLORIC STENOSIS
Erythromycin,
Azithromycin in utero exposure
Genetic assoc. factor of PYLORIC STENOSIS
Turner syndrome (45X), Trisomy 18 (Edwards syndr)
Male, newborn (3rd to 12th wk)
Sx: New onset regurgitation, projectile non-bilious
vomiting aft. feeding
PE: Firm, ovoid, 1-2cm abd. mass @ left/medial side + hyperperistalsis
What is the dx & tx?
PYLORIC STENOSIS
Tx: Myotomy (pyoloromyotomy)
Failure of neural crest cells migration to wall of colon d/t premature arrest of NCC migration or premature death of ganglion cells
HIRSCHSPRUNG DISEASE
→ aka : Congenital Aganglionic Megacolon
Biopsy is done for dx of HIRSCHSPRUNG DISEASE. What immunohistochemical stain is being used?
Acetylcholinesterase
Genetic involvement of HIRSCHSPRUNG DISEASE
- RET gene (& EDNRB gene)
- 10% occur in children with Trisomy 21 (Down syndr)
Male, newborn (upto 1st yr of life) presents w/ abdominal
gaseous distention, delayed meconium passage, and tight anus
PE: No peristalsis
HIRSCHSPRUNG DISEASE
MC site of HIRSCHSPRUNG DISEASE
Distal colon
MC site of MECKEL DIVERTICULUM
Antimesenteric border of ileum
Trisomy 21 (Down syndr)
HIRSCHSPRUNG DISEASE
Turner syndrome (45X), Trisomy 18 (Edwards syndr)
PYLORIC STENOSIS
High amplitude contractions of the distal
esophagus (d/t loss of
the normal coordination of ICOL smooth muscles)
Nutcracker Esophagus
Repetitive, simultaneous contractions of
the distal esophageal smooth muscle (= Uncoordinated propulsion of food)
Diffuse Esophageal Spasm
High pressure on LES
Hypertensive Lower Esophageal Sphincter
CC: feeling of food stuck @ back of throat; Halitosis
ZENKER DIVERTICULUM
Mucosal outfoldings that are non-circumferential
MUCOSAL WEBS
Mucosal outfoldings that are circumferential
SCHATZKI RINGS
SCHATZKI RINGS: A rings
squamous (above
GEJ)
SCHATZKI RINGS: B rings
squamo-columnar, gastric glands (below GEJ)
Dilated veins in the distal esophagus; seen in patients with portal HTN, cirrhosis d/t alcohol or schistosomiasis
VARICES
Complication of chronic GERD; Precursor lesion to Esophageal
Adenocarcinoma
BARRET’S ESOPHAGUS
Mgt for BE indefinite for dysplasia (IND) or low-grade
dysplasia (LGD)
Anti-reflux medical therapy and repeat
endoscopy with biopsy in shorter period of time.
Mgt for BE of high-grade dysplasia (HGD)
Endoscopic ablative therapy (radiofrequency
ablation and cryoablation)
T or F: Most patients with BE never
develop dysplasia or adenocarcinoma.
TRUE
Carcinoma that has penetrated through
the basement membrane of the glands of esophagus
into the lamina propria or muscularis
mucosae, but not below.
Intramucosal adenocarcinoma of BE
HPI:
Swallowing difficulties
Progressive weight loss
Hematemesis
PMH: Chr. GERD
ADENOCARCINOMA of esoph.
*from BE
Genetic factor of Esoph. AdenoCA
Mutation of TP53, CDKN2A(p16/INK4a)
Main features used to suggest an origin for an
esophageal adenocarcinoma from Barrett mucosa
Identification of goblet cells adjacent to the
neoplasm and the epicenter of the tumor being
located on the esophageal side of the GEJ.
MC site of Esoph. SQUAMOUS CELL CARCINOMA
Middle & lower thirds
Mutagenesis of Esoph. SQUAMOUS CELL CARCINOMA
- Alcohol & Tobacco use
- Polycyclic Hydrocarbons, Nitrosamines
- Amplification of transcription factor SOX2
gene - HPV infection
Px presents w/ esoph. tumor w/c is circumferential,
ulcerated, & has sharply demarcated margins.
PSHx: Alcohol & tobacco use
SQUAMOUS CELL CARCINOMA
Common sites of metastasis of Esoph. SQUAMOUS CELL CARCINOMA
LIVER, LUNG, ADRENAL
GLANDS
Causes of STRESS-RELATED MUCOSAL DISEASEs
Trauma; extensive burns;
intracranial disease; major surgery; serious medical disease
PEPTIC ULCER DISEASE: causes & complications
CAUSES: H. pylori infection, NSAID use, Smoking
COMPLICATIONS: Bleeding, Perforation, obstruction
Sx assoc. w/ excess TGF-alpha
- Hypochlorhydria or achlorhydria
- Hypoproteinemia
(MENETRIER DISEASE/ HYPERTROPHIC GASTROPATHY)
Diffuse hyperplasia of foveolar epithelium w/c has an increased risk for adenocarcinoma
MENETRIER DISEASE/ HYPERTROPHIC GASTROPATHY
Parts affected in MENETRIER DISEASE/ HYPERTROPHIC GASTROPATHY
Greater curvature
Body
Fundus
*Antrum is spared
Hyperplasia
primarily affecting the secretory portion of
the fundic gland
ZOLLINGER-ELLISON SYNDROME
ZOLLINGER-ELLISON SYNDROME is assoc. with what syndrome?
MEN (Multiple Endocrine Neoplasia) type 1
ZOLLINGER-ELLISON SYNDROME mainly involves what kind of cells?
Parietal cells
ECL cells
*both resulting from gastrin stimulation
Generally small, sessile, and multiple, with a smooth or slightly lobulated contour; randomly distributed in the stomach
HYPERPLASTIC POLYPS
Tend to arise
in a background of hypochlorhydria, low levels of pepsinogen I,
hypergastrinemia, chronic gastritis, and gastric atrophy
HYPERPLASTIC POLYPS
Multiple small polypoid projections in the
gastric fundus or body
FUNDIC GLAND POLYP
FUNDIC GLAND POLYP occur in?
- Sporadically
- Pxs w/ ZES
- Long term PPI tx
- Pxs w/ FAP
Molecular alteration in FUNDIC GLAND POLYP
- Sporadic fundic gland polyps: mutation of
β-catenin gene - With FAP: second hit alterations in APC gene
Cystically dilated irregular
glands lined by parietal, chief, and foveolar mucosal
cells
FUNDIC GLAND POLYP
Associated with familial adenomatous polyposis
(FAP) and background of chronic gastritis
GASTRIC ADENOMA
Type of GASTRIC ADENOMA w/ higher tendency for malignant transformation
Intestinal-type adenomas
Known as linitis plastica/ signet ring adenoCA
Diffuse type gastric adenoCA
Molec. pathogenesis involved in diffuse type gastric adenoCA
CDH1 gene
Molec. pathogenesis involved in both diffuse & intestinal type gastric adenoCA
TP53
Molec. pathogenesis involved in sporadic intestinal type gastric adenoCA
- WNT pathway
- Beta catenin
- APC gene
Identified precursor lesion for both diffuse & intestinal type gastric adenoCA
- Diffuse type: No identified precursor lesion
- Intestinal type: Barrett’s Esophagus; Flat dysplasia and Adenoma
GASTRIC ADENOCARCINOMA advanced stages sx
weight loss, anorexia, early satiety
Female patient – signet ring on bilateral ovaries,
diffused type gastric carcinoma
Krukenberg tumor.
H. pylori infection provides the necessary background in which this tumor develops
MALT Lymphoma
MALT Lymphoma molec pathogenesis
Translocation AP12-MLT fusion gene
Small, sharply outlined, and covered by a flattened mucosa; linked to PPI tx
CARCINOID TUMORS/ Well differentiated-Neuroendocrine tumors
Most important prognostication factor for WDNETs
Location
o Foregut: rarely metastasize; cured by resection.
o Midgut: Aggressive
o Hindgut: Incidental; more benign
Mesenchymal neoplasm of the abdomen
GASTROINTESTINAL STROMAL TUMOR
GIST location
● 60% occur in the stomach. ● 60% submucosal growing towards lumen creating a smooth projection. ● 30% are subserosal ● 10% are intramural
Carney Triad
- Nonhereditary syndrome of GIST
- Paraganglioma
- Pulmonary chondroma
Most common site of Metastasis of GIST
LIVER
LUNGS
PERITONEUM
Mutagenesis of GIST
Gain of function of c-KIT gene
Becomes emergency when there is bowel obstr’n → need to do reduction
INTESTINAL HERNIA
Obstructive sx bec peristalsis is affected;
Caused by surg. procedures/ infxn/ peritoneal inflam’n.
INTESTINAL ADHESION
MC site of VOLVOLUS
- MC: Sigmoid colon
- Other sites: cecum, small bowel, stomach, transverse colon.
Lymphoid hyperplasia precedes this, and are particularly seen during the first 5 years of life
Intussusception
Watershed zones
Splenic Flexure, Sigmoid Colon and Rectum
An immune-mediated disease due to an abnormal
response certain proteins in
genetically susceptible people.
CELIAC DISEASE
Characterized by scalloping and denting of the duodenal folds with markedly atrophic or absent villi.
CELIAC DISEASE
Endoscopically, small bowel shows white lipid-filled
plaques in the mucosa which represents macrophages in the lamina propria
WHIPPLE DISEASE
Flask-like outpouchings alongside the taenia coli caused by Elevated intraluminal pressure
SIGMOID DIVERTICULAR DISEASE
Thin wall composed of flattened or atrophic
mucosa, compressed submucosa, often absent
muscular layer
SIGMOID DIVERTICULAR DISEASE
Main complications of diverticulosis
Hemorrhage, perforation, and diverticulitis.
TX: Acute uncomplicated diverticulitis vs patients with
complications of diverticulitis
Acute uncomplicated : Abx
With complications of diverticulitis: Surgical
resection
HYPERPLASTIC POLYP size & location
Left colon; <5 mm
Genetic defect in juvenile polyposis
inherited inactivating mutations of the SMAD4 or BMPR1A genes,
The standard treatment for adenomatous polyps
polypectomy, followed by repeated
colonoscopy.
TUBULAR ADENOMA size
Measure less than 1 cm
Sometimes clusters of dysplastic glands in an
adenomatous polyp are seen beneath the
muscularis mucosae and may lead to a
mistaken diagnosis of malignant transformation
“Pseudoinvasion”
Represent the earliest identifiable
“adenomatous” change; numerous in colons harboring carcinoma
“Aberrant crypts”
Large polyps located at the right side of the colon
SESSILE SERRATED ADENOMAS
100% of untreated cases progress into Colorectal
Adenocarcinoma
FAMILIAL ADENOMATOUS POLYPOSIS
Genetic involvement in FAP
● Autosomal Dominant Disorder
● APC gene
● Other genes: MYH gene
Genetic defect in LYNCH SYNDROME/ HNPCC
- MLH1
- MSH2
-Also, MSH6, PMS2
Genetic defect in INT. ADENOCARCINOMA
APC
KRAS
TP53
T or F: Smooth muscle tumors situated higher up in the colon have a higher incidence of malignancy.
TRUE
T or F: Colorectal malignant lymphomas are nearly
always of non- Hodgkin type.
TRUE
