Stomach, Small intestine/colon, Salivary gland, Pancreas, and Oral Cavity Pathology Flashcards
What are the normal damaging factors to the gastric muscosa?
- Gastric acidity
- Peptic enzymes
What are the normal protective factors to the gastric muscosa?
- Surface mucus secretion
- Bicarbonate secretion into mucus
- Mucosal blood flow
- Epithelial barrier function
- Epithelial regenerative capacity
- Elaboration of prostaglandins
What are some external factors that damage the gastric mucosa?
- H. pylori infection
- NSAIDs
- Tobacco
- Alcohol
- Gastric hyperacidity
- Duodenal-gastric reflux
What are some internal factors that damage the gastric mucosa?
- Ischemia
- Shock
- NSAIDs
- Radiation
- Chemotherapy
What do exogenous prostaglandins do?
- Inhibit acid secretion
- Stimulate mucus and bicarbonate secretion
- Alter mucosal blood flow
- Provide dramatic protection against wide variety of agents which cause acute mucosal damage
What is the molecular defect of FAP?
- APC/WNT pathway
What are the target genes in FAP?
- APC
What is the transmission of FAP?
- AD
What is the histology of FAP?
- Tubular, villous, typical adenocarcinoma
What is the molecular defect of MYH-associated polypsis?
- DNA mismatch
What are the target genes of MYH-associated polypsis?
- MYH
What is the transmission of MYH-associated polypsis?
- AR
What is the histology of MYH-associated polypsis?
- Sessile serrated adenoma; mucinous adenocarcinoma
What is the molecular defect of hereditary nonpolyposis colorectal cancer?
DNA mismatch repair
What are the target genes of hereditary nonpolyposis colorectal cancer?
- MSH2
- MLH1
What is the transmission of hereditary nonpolyposis colorectal cancer?
- AD
What is the histology of hereditary nonpolyposis colorectal cancer?
- Sessile serrated adenoma; mucinous adenocarcinoma
What is the molecular defect of sporadic colon cancer?
- APC/WNT pathway
What are the target genes of sporadic colon cancer?
- APC
What is the histology of sporadic colon cancer?
- Tubular, villous; typical adenocarcinoma
What is the peak age for colonic adenocarcinoma?
- 60-70s
What is the clinical presentation of FAP?
- AD disorder in which patients develop numerous colorectal adenomas as teenagers
What do carcinomas in the distal colon look like?
- Tend to be annular lesions that produce “napkin-ring” contractions and luminal narrowing
What is Peutz-Jeghers syndrome?
- AD syndrome that presents at a median age of 11 years with multiple GI hamartomatous polyps and mucocutaneous hyperpigmentation
What regions of the body are hyperpigmented in Peutz-Jeghers?
- Lips
- Nostrils
- Buccal mucosa
- Palmar surfaces of hands
- Genitalia
- Perianal region
What is the LOF mutation in Peutz-Jeghers?
- STK11
What is fatal in Peutz-Jeghers?
- Intussusception
What do people with Peutz-Jeghers most at risk for?
- Risk of colon, breast, lung, pancreatic, and thyroid cancer
In whom is IBD more likely?
- Teens/early 20s
- Caucasians
- 3-5x more likely in Ashkenazi Jews
- Most common in North America, Europe, and Australia
What area of the GI tract does Crohn’s disease affect?
- Any area of the GI tract but most commonly involves the terminal ileum, ileocecal valve, and cecum
What area of the GI tract does ulcerative colitis affect?
- Colon only
What is the distribution of crohn disease?
- Skip lesions
- Have creeping fat
What is the distribution of ulcerative colitis?
- Diffuse
What is the earliest sign of crohn disease?
- Aphthous ulcer
- Multiple lesion often coalesce into elongated, serpentine ulcers oriented along the axis of the bowel
Is there a stricture in crohn disease?
- Yes
Is there a stricture in ulcerative colitis?
- Rarely
What does the colonic wall look like in crohn disease?
- Thick
What does the colonic wall look like in ulcerative colitis?
- Thin
What does the inflammation look like in crohn disease?
- Transmural
What does the inflammation look like in ulcerative colitis?
- Limited to mucosa
What do the ulcers look like in crohn disease?
- Deep, knife like
What do the ulcers look like in ulcerative colitis?
- Superficial, broad-based
What is the clinical presentation of crohn disease?
- Perianal fistula (in colonic disease)
- Fat/vitamin malabsorption
- Malignant potential with colonic involvement
- Common recurrence after surgery
- No toxic megacolon
What is the clinical presentation of ulcerative colitis?
- No perianal fistula
- No fat/vitamin malabsorption
- Malignant potential
- Surgery is curative
- Toxic megacolon is present
What are the presenting symptoms of crohn disease?
- Abdominal pain
- Diarrhea
- Nausea
- Vomiting
- Weight loss
What are the presenting symptoms of ulcerative colitis?
- Abdominal pain
- Rectal bleeding
- Bloody diarrhea
What else is pseudomembranous colitis called?
- Antibiotic associated colitis or antibiotic associated diarrhea
What causes pseudomembranous colitis?
- Disruption of the normal colonic microbiota by antibiotics allows overgrowth of C. difficile
What are the pseudomembranes made up of?
- An adherent layer of inflammatory cells and debris are not specific and may also be present in ischemia or necrotizing infections
What is the presentation of pseudomembranous colitis?
- Fever
- Leukocytosis
- Abdominal pain
- Cramps
- Watery diarrhea
- Dehydration
What is potentially fatal complication of pseudomembranous colitis?
- Toxic megacolon
How is diagnosis made of pseudomembranous colitis?
- Presence of C. difficile toxin
What are effective therapies for antibiotic resistant or hypervirulent C. difficile?
- Metronidazole and vancomycin
What is xerostomia?
- Lack of saliva
What is the etiology of xerostomia?
- Most frequently due to medications
- Major feature in Sjogren syndrome
- Radiation therapy
Which salivary gland is most affected by mucoepidermoid carcinoma?
- Parotid gland but could show up in others
What is the chromosomal translocation of mucoepidermoid carcinoma?
- (11:19)(q21;p13)
What is the prognosis of mucoepidermoid carcinoma based on?
- Grade
What is the clinical manifestation of acute pancreatitis?
- Abdominal pain
- Pain is constant, intense, and referred to the upper back and, occasionally the left shoulder
- Anorexia, nausea and vomiting are common
What are the laboratory findings in acute pancreatitis?
- Elevation of serum amylase and lipase during the first 4-12 hours following the onset of pain
- Serum lipase is the most specific and sensitive marker of acute pancreatitis (remains elevated for 8-14 days
- Glycosuria and hypocalcemia could result from saponification of necrotic fat
What signs are associated with acute pancreatitis?
- Periumbilical ecchymosis (Cullen’s sign)
- Ecchymosis of the flank (Grey Turner’s sign)
What causes the ecchymosis of the abdomen in acute pancreatitis?
- Liberated pancreatic enzymes causing the diffusion of fat necrosis and inflammation in the retroperitoneal or intra abdominal bleeding
What does the ecchymosis of the abdomen in acute pancreatitis mean?
- Not specific but associated with severe acute pancreatitis and mortality
What is the ratio of men to women in acute pancreatitis? What are the causes?
- 6:1 male to female in alcoholism
- 1:3 male to female in biliary tract disease
What is present in around half of acute pancreatitis patients?
- Gallstones
What is the pathogenesis of acute pancreatitis?
- Tissue damage commences and trypsin can activate factors found in the blood including components of coagulations, complement, kallikrein, and fibrinolytic pathways
- The resulting inflammation and small vessel thrombosis causes further damage to acinar cells, amplifying intrapancreatic enzyme activiation
What does the CFTR gene do?
- Epithelial anion channel. LOF mutations alter fluid pressure and limit bicarbonate secretion, leading to inspissation of secreted fluids and duct obstruction
What does the PRSS1 gene do?
- Cationic trypsin. GOF mutations prevent self-inactivation of trypsin
What does the SPINK1 gene do?
- Inhibitor of trypsin. Mutations cause LOF, increasing trypsin activity
What does CASR gene do?
- Membrane-bound receptor that senses extracellular calcium levels and controls luminal calcium levels . Mutations may alter calcium concentrations and activate trypsin
What does the CTRC gene do?
- Degrades trypsin, protects the pancreas from trypsin related injury
What does the CPA1 gene do?
- Exopeptidase involved in regulating zymogen activation
What are some basic alterations in the morphology of acute pancreatitis?
- Microvascular leak and edema
- Fat necrosis
- Acute inflammation
- Damage, including autodigestion, of pancreatic parenchyma, and
- Blood vessel destruction with interstitial hemorrhage
What is chronic pancreatitis defined as?
- Prolonged inflammation of the pancreas associated with irreversible destruction of exocrine parenchyma, fibrosis, and, in the late stages, loss of endocrine parenchyma
What is the most common cause of chronic pancreatitis?
- Long-term alcohol use
How many forms are there of autoimmune pancreatitis?
- Two
What is autoimmune pancreatitis type 1?
- Associated with the presence of immunoglobulin G4 (IgG4) –> secreting plasma cells in the pancreas and is one manifestation of a systemic IgG-related disease
What is autoimmune pancreatitis type 2?
- Restricted to the pancreas with the exception of a subset of patients with ulcerative colitis.
What do both variants of the autoimmune pancreatitis mimic?
- Pancreatic carcinoma, including presentation as a mass lesion in the pancreatic head on imaging
How is the diagnosis of chronic pancreatitis made?
- High degree of suspicion
- Repeated bouts of abdominal pain
- Persistent back pain
- Calcifications
- Pseudocyst
- Pancreatic exocrine insufficiency
- Diabetes mellitus
What can all lead to significant morbidity and contribute to mortality?
- Chronic malabsorption
- Pancreatic exocrine insufficiency
- Diabetes mellitus
What is a dominant problem in chronic pancreatitis?
- Severe, chronic pain
What happens in patients with hereditary pancreatitis associated with PRSS1?
- Mutations have a 40% lifetime risk of developing pancreatic cancer
- RIsk of pancreatic cancer is only modestly elevated with other forms of chronic pancreatitis
What is leukoplakia?
- A white patch or plaque that cannot be scraped off and cannot be characterized clinically or pathologically with any other disease
What is a special quality of leukoplakia?
- Up to 25% are precancerous
What is erythroplakia?
- A red, velvety, possibly eroded area within the oral cavity that usually remains level or may be slightly depressed in relation to the surrounding mucosa
Which is less common: leukoplakia or erythroplakia?
- Erythroplakia
What is a special quality of erythroplakia?
- Is more ominous because it is almost always associated with severe dysplasia/CIS
What causes most orofacial herpetic infections?
- HSV-1 is most common
- Oral HSV-2 (genital herpes) can occur
What is the primary age of oral HSV?
- Typically occur in children between 2 and 4, are often asymptomatic
What do the vesicles of HSV look like?
- Range from lesions of a few millimeters to large bullae
- First filled with a clear, serous fluid, but rapidly to yield painful, red-rimmed, shallow ulcerations
When do the HSV vesicles usually clear?
- Spontaneously clear within 3-4 weeks
What test can be used for HSV?
- Tzanck test
What is the most common fungal infection of the oral cavity?
- Candidiasis
What factors influence clinical infection of candidiasis?
- Strain of C. albicans
- Composition of individual oral flora
- Immune status of the patient
What is important for the protection against Candida infection?
- Neutrophils, macrophages, and Th17 cells
What does histology look like for Candida?
- Pseudohyphae, budding yeast, and human epithelial cells
What is an important diagnostic clue for Candida?
- Pseudohyphae