SI and Colon Path Flashcards
Intestinal Obstruction Symptoms (4) and Causes (4)
Abdominal pain
Distension
Vomiting
Constipation
Hernias: most common worldwide
Adhesions: most common in US
Intussusceptions: most common in babies
Volvulus: mostly in sigmoid colon
Melena vs Hematochezia Characteristics (2 each)
Melena
Coffee ground stool
Upper GI bleeds
Hematochezia
Bright Red Blood Per Rectum (BRBPR)
Colon bleeds
Ischemic Bowel Disease
Population (3) Presentation (3) and Worst Vessel to Occlude
People over 70 with comorbid Cardiac or Vascular disease
Cramping abdominal pain
Need to defecate
Hematochezia
Superior Mesenteric Artery
Other Causes of Intestinal Bleeding with Descriptions (3)
Necrotizing Enterocolitis
Premie infants once oral feeding starts**
Angiodysplasia
Malformed cecum/Ascending colon vessels**
Radiation Enterocolitis
See radiation fibroblasts in stroma
Malabsorptive Diarrhea
Most Common Causes (3) and Presentation (5)
Pancreatic Insufficiency (Cystic Fibrosis patients)
Celiac’s Disease
Crohn’s Disease
Steatorrhea*** Flatus Abdominal pain Borborygmi (growling sound) Anorexia/WL/Muscle Wasting
4 Types of Diarrhea with Descriptions
Secretory
Isotonic stool, persists during fasting
Osmotic
Hypertonic stool, abates while fasting
Malabsorptive
Steatorrhea, abates while fasting
Exudative
Purulent and bloody, continues while fasting
Celiac’s Disease
Pathogenesis (2), Morphology, Diagnosis (6), Clinical (4)
MHC II molecules with HLA-DQ2/DQ8 polymorphism interact with gliadin molecules
NKG2D expressing T cells activated
Villous atrophy causing flattened mucosa
Biopsy: increased CD8+ T cells, Villous atrophy and Crypt hyperplasia
Serology: IgA Abs to tTG or Gliadin
IgG Abs to DGP
Dermatitis Herpetiformis
Chronic malabsorptive diarrhea
Iron deficiency anemia
Increased risk of enteropathy associated T cell lymphoma
Environmental Enteropathy (Tropical sprue) Populations (2) Clinical Features (4)
Present in populations with poor santiation and developing nations
Malabsorption (malnutrition)
Stunted Growth
Defective intestinal mucosa immune function
Cognitive deficits
Autoimmune Enteropathy
Genetics (1), Presentation (2)
Severe Form Characteristics (4)
X Linked Disorder
Severe Persistent Diarrhea
Presents in young children
IPEX: Immune dysregulation (FOXP3 mutation) Polyendocrinopathy Enteropathy X Linked
Lactase Disaccharidase Deficiency
Presentation (3) and Types (2)
Explosive watery diarrhea
Frothy stool
Abdominal distension
Congenital: Autosomal recessive enzyme deficiency
Acquired: Downregulated lactase gene post infection
Abetalipoproteinemia
Pathogenesis (2) and Presentation (5)
Autosomal recessive mutation of microsomal triglyceride transfer protein
Causes inability to absorb essential fatty acids
Presents in infancy with: Failure to thrive Steatorrhea Acanthocytic red cells (Burr cells) Fat soluble vitamin deficiency Lipid membrane defects
Irritable Bowel Syndrome Clinical Features (4)
Chronic relapsing abdominal pain
Abdominal distension
Changes in bowel habits
No pathological abnormalities
Crohn's Disease Gross Features (4) and Histology (5)
Skip lesions
Cobblestone mucosa
Apthous ulcers coalescing into serpentine Ulcers
Affects whole GI, rectum spared
Transmural inflammation
Paneth cell metaplasia
Noncaseating granulomas
Metastatic Crohn disease (lymph node granulomas)
Ulcerative Colitis Gross Features (5) and Histology (2)
Broad based ulcers Continuous lesions Pseudopolyps creating mucosal bridges Toxic megacolon Affects colon and rectum
Diffuse inflammation of mucosa/superficial submucosa
Crypt abscesses
NO granulomas
Diversion Colitis Clinical Setting (3) and Histology (3)
Post-surgery for Ulcerative colitis, Hirschsprung disease and others requiring colostomy
Mucosal erythema
Mucosal Friability
Development of lymphoid follicles
Microscopic Colitis
Presentation (3) Collagenous (2) and Lymphocytic (3)
Chronic, nonbloody watery diarrhea without weight loss
Collagenous: Thickened subepithelial collagen and increased inflammatory cells
Lymphocytic: normal collagen layer and greatly increased immune cells
Associated with Celiacs and autoimmune diseases
Graft vs Host Disease
Clinical Setting and Histology
Post hematopoietic stem cell transplantation
Epithelial apoptosis of crypt cells
Colonic Diverticular Disease Clinical Features (5) and Morphological Features (4)
Very common in people over 60 Intermittent cramping Continuous lower abdominal discomfort Constipation/Distention Mostly asymptomatic
Flask-like outpouchings along teniae coli
Mostly in sigmoid colon
Atrophic mucosa
Absent muscularis propria
Hamartomatous Polyps
Causes (3) and Complications
Can arise sporadically
Genetic or Acquired syndromes
Germline mutations in tumor suppressor or proto-oncogenes
Extra-intestinal manifestations
Risk of cancer (considered pre-neoplastic lesions)
Peutz-Jeghers Syndrome
Age, Genes, Location, Extraintesinal Manifestations (2)
10-15 years
STK11 mutation
Arborizing polyps mainly in Small intestine
Mucocutaneous Hyperpigmentation*
Colon, Breast, Lung, Pancreatic, Thyroid Cancers
Juvenile Polyposis
Age, Genes (2), GI Complications (4), Extraintesinal Manifestation
Age < 5 years
SMAD4 and BMPR1A
Increased risk of adenocarcinoma in:
Stomach, Small Intestine, Colon, Pancreas
Digital clubbing
Familial Adenomatous Polyposis
Age, Genes, GI Complications, Extraintesinal Manifestation
10-15 years
APC mutation
Multiple adenomas
Retinal pigment epithelium hypertrophy*
Sporadic Colorectal Neoplasia Molecular Defects (3), Target Genes (3), Side, Tumor Types (2)
Wnt pathway, Microsatellite instability, Beta-catenin
APC, MSH2, MLH1
Mostly right sided
Sessile serrated adenoma
Mucinous adenocarcinoma
Hereditary Nonpolyposis Colorectal Cancer (HNPCC)
Molecular Defect, Target Genes (2), Inheritance, Side, Tumor Types (2)
DNA mismatch repair
MSH2 and MLH1 defects
Autosomal dominant inheritance
Right sided
Sessile serrated adenoma
Mucinous adenocarcinoma
Colonic Adenocarcinoma
Epidemiology (2), Genetics (2), Morphology (2)
Most common GI malignancy
Highest incidence in US
APC/Beta-catenin pathways
Proximal colon: polypoid, exophytic masses
Distal colon: annular lesions (napkin ring obstruction)
Colonic Adenocarcinoma Prognostic Features (2), Metastasis Site and Right/Left Sided Presentations
Prognosis based on depth and LN metastasis
Most commonly metastasizes to liver
Right: Iron deficiency anemia (fatigue, weak)
Left: Occult bleeding, BM changes, LLQ discomfort
What are TNM and AJCC used for in colon cancer?
TNM is original prognostic classification
AJCC is newer system for staging tumors
