Abdomen and Pelvis Flashcards
Achalasia is characterized by the triad of: x,x and x
Causes:
incomplete lower esophageal sphincter relaxation, increased lower esophageal sphincter tone, and aperistalsis of the esophagus
Although there is some increased risk for esophageal cancer, it is not considered great enough to warrant surveillance endoscopy
Primary very rare
Chagas disease - most common
Other causes of achalasia-like disease include diabetic autonomic neuropathy; infiltrative disorders such as malignancy, amyloidosis, and sarcoidosis; systemic sclerosis; or lesions of dorsal motor nuclei (e.g., following polio). Lower esophageal sphincter dysfunction also occurs in association with Down syndrome or as part of Allgrove (triple-A) syndrome, an autosomal recessive disorder characterized by achalasia, alacrima, and adrenocorticotropic hormone–resistant adrenal insufficiency. The association of some achalasia cases with remote herpes simplex virus 1 (HSV1) infection, linkage of immunoregulatory gene polymorphisms to achalasia, and occasional coexistence of Sjögren syndrome or autoimmune thyroid disease suggest that achalasia may also be driven by immune-mediated destruction of inhibitory esophageal neurons
Esophageal Causes of Hematemesis
Barrett esophagus is a complication of chronic GERD that is characterized by x within the esophageal squamous mucosa and is associated with an increased risk of cancer
intestinal metaplasia
H. pylori are spiral-shaped or curved bacilli present in gastric biopsy specimens of almost all patients with x ulcers as well as most individuals with gastric ulcers or chronic gastritis. Acute H. pylori infection does not produce sufficient symptoms to come to medical attention in most cases; it is the chronic gastritis that ultimately causes the individual to seek treatment. H. pylori organisms are present in the majority of individuals with chronic antral gastritis.
duodenal
The x is the preferred biopsy site for evaluation of H. pylori gastritis because it is most commonly infected.
antrum
Autoimmune atrophic gastritis is characterized by:
…, what cells involved
?location
*Autoimmune atrophic gastritis is associated with loss of parietal cells, which are responsible for secretion of gastric acid and intrinsic factor. Antibodies can be detected in serum and gastric secretions.
The absence of acid production stimulates gastrin release, resulting in hypergastrinemia and hyperplasia of antral gastrin-producing G cells. Vitamin B 12 deficiency
Autoimmune atrophic gastritis is characterized by diffuse damage to the oxyntic (acid-producing) mucosa within the body and fundus. The antrum and cardia are typically spared.
Risk Factors for Peptic Ulcer Disease
Stomach cancer
The risk of adenocarcinoma is greatest in x
autoimmune metaplastic atrophic gastritis.
After H. pylori and NSAIDs, autoimmune atrophic gastritis is the most frequent cause of chronic gastritis.
x develops in all forms of chronic gastritis and is a risk factor for x.
Intestinal metaplasia
gastric adenocarcinoma
Most gastric adenomas develop in a background of chronic gastritis with atrophy and intestinal metaplasia, with the exception of those associated with germline mutations in APC or MUTYH.
The risk of adenocarcinoma within gastric adenomas correlates with size and is particularly elevated in lesions greater than x cm in diameter.
Gastric adenomas have a greater risk of cancer (up to 30% when large) and must be managed more aggressively than colonic adenomas.
2cm
x loss is a key step in the development of diffuse gastric cancer. CDH1 mutations are also common in sporadic and familial lobular carcinoma of the breast, which, like diffuse gastric cancer (see later), tends to infiltrate as single cells.
In contrast to diffuse gastric cancers, intestinal-type gastric cancers are strongly associated with mutations x.
E-cadherin
that result in increased signaling via the Wnt pathway
Stomach cancer
Diffuse infiltrative growth pattern are typically composed of x
intestinal morphology form bulky tumors and are composed of glandular structures
signet-ring cells
*The depth of invasion and the extent of nodal and distant metastases remain the most powerful prognostic indicators in gastric cancer.
A mass may be difficult to appreciate in diffuse gastric cancer, but these infiltrative tumors often evoke a desmoplastic reaction that stiffens the gastric wall. When there are large areas of infiltration, diffuse rugal flattening and a rigid, thickened wall may impart a leather bottle appearance termed x
linitis plastica
Although extranodal lymphomas can arise in virtually any tissue, they do so most commonly in the GI tract, particularly the x.
stomach
*Nearly 5% of all gastric malignancies are primary lymphomas, the most common of which are indolent extranodal marginal zone B-cell lymphomas. In the gut these tumors are often referred to as lymphomas of MALT, or MALTomas.
Extranodal marginal zone B-cell lymphomas usually arise at sites of chronic inflammation.
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the abdomen.
More than half of these tumors occur in the x.
The term stromal reflects historical confusion about the origin of this tumor, which is now recognized to arise from the interstitial cells of x
increased incidence of GIST in individuals with neurofibromatosis type x
stomach
Cajal, or pacemaker cells
NF1
Approximately 75% of all GISTs have oncogenic, gainof-function mutations in the receptor x
GISTs composed of thin elongated cells are classified as x cell type
tyrosine kinase KIT. Most useful diagnostic marker is KIT (CD117), which is immunohistochemically detectable in Cajal cells and 95% of gastric GISTs
spindle
Recurrence or metastasis is rare for gastric GISTs smaller than 5 cm but common for mitotically active tumors larger than 10 cm.
Celiac disease, also known as celiac sprue or glutensensitive enteropathy, is x
Celiac disease, also known as celiac sprue or glutensensitive enteropathy, is an immune-mediated disorder triggered by the ingestion of gluten-containing foods such as wheat, rye, or barley in genetically predisposed individuals.
Coeliac
A characteristic itchy, blistering skin lesion, x, can be present in as many as 10% of patients.
dermatitis herpetiformis
Coeliac.
The most sensitive test is the measurement of x.
IgA antibodies against tissue transglutaminase. (anti-tTG), IgA
IgA antiendomysial antibodies can also be present.
The absence of HLA-DQ2 and HLA-DQ8 is useful for its negative predictive value, but the presence of these alleles is not helpful in confirming the diagnosis
Diarrhea can be characterized as x4
secretory, osmotic, malabsorptive, or exudative.
- Secretory diarrhea is characterized by isotonic stool and persists during fasting. E.g. V. cholerae, VIPoma
- Osmotic diarrhea, such as occurs with lactase deficiency, is due to the excessive osmotic force exerted by unabsorbed luminal solutes. The diarrhea fluid is more than 50 mOsm more concentrated than plasma, and diarrhea abates with fasting.
- Malabsorptive diarrhea follows generalized failure of nutrient absorption, is associated with steatorrhea, and is relieved by fasting. E.g. Acute radiation enteritis, atrophic gastritis, celiac
- Exudative diarrhea due to inflammatory disease is characterized by purulent, often bloody stools that continue during fasting. E.g. salmonell,shigella
Campylobacter infection can result in reactive arthritis, primarily in patients with x
HLA-B27 genotype.
Other extraintestinal complications, including erythema nodosum and Guillain-Barré syndrome, a flaccid paralysis caused by immunologically mediated inflammation of peripheral nerves (Chapter 27), are not HLA-linked
Salmonella infection causes x in the terminal ileum to enlarge into sharply delineated, plateau-like elevations up to 8 cm in diameter.
Peyer patches
Patients with x are particularly susceptible to Salmonella osteomyelitis.
sickle cell disease
While other organisms such as Salmonella, Clostridium perfringens type A, or Staphylococcus aureus may also produce diarrhea in the context of antibiotic therapy, only x causes pseudomembranous colitis.
C. difficile
Risk factors for C. difficile–associated colitis include …
antibiotic treatment, advanced age, hospitalization, and immunosuppression.
Features That Differ Between Crohn Disease and Ulcerative Colitis
Extraintestinal manifestations of IBD include …
cutaneous nodules formed by granulomas, uveitis, migratory polyarthritis, sacroileitis, ankylosing spondylitis, erythema nodosum, cutaneous granulomas, and clubbing of the fingertips, any of which may develop before intestinal disease is recognized.
Pericholangitis and primary sclerosing cholangitis occur in individuals with Crohn disease with a higher frequency than in those without Crohn disease, but are even more common in individuals with ulcerative colitis Approximately 2.5% to 7.5% of individuals with ulcerative colitis also have primary sclerosis cholangitis
As discussed later, risk of colonic adenocarcinoma is increased in patients with long-standing colonic disease.
Gastrointestinal Polyposis Syndromes
Although most colorectal adenomas are benign lesions, a small proportion harbor invasive cancer at the time of detection.
Size is the most important characteristic that correlates with risk of malignancy. For example, while cancer is extremely rare in adenomas less than x in diameter, nearly 40% of lesions larger than x in diameter contain foci of invasive cancer.
High-grade dysplasia is also a risk factor for cancer in an individual polyp, but does not confer an increased risk of cancer in other polyps within the same patient.
1 cm
4 cm
Familial adenomatous polyposis (FAP) is an x(inheritance) disorder in which patients develop numerous colorectal adenomas as teenagers.
It is caused by somatic mutations of the adenomatous polyposis coli, or APC, gene, which is a key negative regulator of the Wnt signaling pathway.
Approximately x% of cases are inherited, while the remainder appear to be caused by de novo mutations.
autosomal dominant
75%
At least 100 polyps are necessary for a diagnosis of classic FAP, but thousands may be presen
Colorectal adenocarcinoma develops in 100% of untreated FAP patients, often before age x and nearly always by age x.
30
50
Colectomy prevents colorectal cancer, but patients remain at risk for neoplasia at other sites.
The x and x are common extracolonic sites of adenomas in FAP patients.
ampulla of Vater
stomach
Common Patterns of Sporadic and Familial Colorectal Neoplasia
HNPCC is caused by x
Often located in the x colon
There are at least five mismatch repair genes, but the majority of patients with HNPCC have mutations in …
inherited mutations in mismatch repair genes that encode proteins responsible for the detection, excision, and repair of errors that occur during DNA replication
Often located in the right colon
There are at least five mismatch repair genes, but the majority of patients with HNPCC have mutations in MSH2 or MLH1.
Colon adenocarcinomas, the two most important prognostic factors are …
depth of invasion and the presence of lymph node metastases.
Invasion into the muscularis propria significantly reduces the probability of survival, which is decreased further by the presence of lymph node metastases
Intestinal polyps can be classified as nonneoplastic or neoplastic.
The nonneoplastic polyps can be further subclassified as …
Benign epithelial neoplastic polyps of the intestines are termed adenomas. The hallmark of these lesions, which are the precursors of colonic adenocarcinomas, is …
hyperplastic, inflammatory, or hamartomatous
cytologic dysplasia
APC/β-catenin pathway, which is activated in the classic adenoma-carcinoma sequence
The classic adenoma-carcinoma sequence accounts for up to 80% of sporadic cancers and typically includes mutation of APC early in the neoplastic process
Both copies of the APC gene must be functionally inactivated, either by mutation or by epigenetic events, for adenomas to develop. The APC protein normally binds to and promotes degradation of β-catenin, a component of the Wnt signaling pathway. With loss of APC function, β-catenin accumulates and and activate Wnt signaling
Other changes, including mutation of KRAS, losses at 18q21 involving SMAD2 and SMAD4, and inactivation of the tumor suppressor gene TP53, lead to the emergence of carcinoma.
MSI pathway, which is associated with defects in DNA mismatch repair and accumulation of mutations in microsatellite repeat regions of the genome
Morphologic and molecular changes in the mismatch repair pathway of colon carcinogenesis. Defects in mismatch repair genes result in microsatellite instability and permit accumulation of mutations in numerous genes. If these mutations affect genes involved in cell survival and proliferation, cancer may develop.
MLH1, MSH2
TGFBR2, BAX, BRAF, TCF4, IGF2R, others
The anal canal can be divided into thirds.
What are they + ?epithelium
The upper zone is lined by columnar rectal epithelium; the middle third by transitional epithelium; and the lower third by stratified squamous epithelium.
Diagnosis of acute appendicitis requires neutrophilic infiltration of the x.
muscularis propria
Acute liver failure is defined as an acute liver illness associated with encephalopathy and coagulopathy that occurs within x weeks of the initial liver injury in the absence of preexisting liver disease.
26
Accidental or deliberate ingestion of acetaminophen accounts for almost x% of adult cases in the United States, while autoimmune hepatitis, other drugs/toxins, and acute hepatitis A and B infections account for most remaining cases.
In Asia, acute hepatitis x&x are the predominant causes.
50%
B and E
manifestations of acute liver failure are as follows:
liver enlarged, then shrinkage
Cholestasis
Hepatic encephalopathy
Coagulopathy:Easy bruisability is an early sign, which can progress to life-threatening or fatal intracranial bleeding.
Portal hypertension
Hepatorenal syndrome is a form of renal failure occurring in individuals with liver failure
The leading causes of chronic liver failure worldwide are …
chronic hepatitis B, chronic hepatitis C, nonalcoholic fatty liver disease, and alcoholic liver disease.
Location and Causes of Portal Hypertension
The four major consequences of portal hypertension are
(1) hepatic encephalopathy (described under liver failure), (2) ascites, (3) the formation of portosystemic venous shunts, and (4) congestive splenomegaly.
Portosystemic Shunts
The principal sites are veins around and within the rectum (manifest as hemorrhoids), the esophagogastric junction (producing varices), the retroperitoneum, and the falciform ligament of the liver (involving periumbilical and abdominal wall collaterals). Abdominal wall collaterals appear as dilated subcutaneous veins extending from the umbilicus toward the rib margins (caput medusae)
The mnemonic for causes of acute liver failure is as follows:
- A: Acetaminophen, hepatitis A, autoimmune hepatitis
- B: Hepatitis B
- C: Hepatitis C, cryptogenic
- D: Drugs/toxins, hepatitis D
- E: Hepatitis E, esoteric causes (e.g.,Wilson disease, Budd-Chiari syndrome, lymphoma, carcinoma)
- F: Fatty change of the microvesicular type (e.g., fatty liver of pregnancy, valproate, tetracycline, Reye syndrome)
Potential outcomes of hepatitis B infection in adults
Hepatitis C Virus (HCV) x causes symptomatic acute hepatitis, but it is the x cause of chronic viral hepatitis.
rarely
most common
Hepatitis viruses
% progress to chronic
Viral hepatitis accounts for a mately 10% of cases of acute hepatic failure. Hepatitis x and x are the most common causes worldwide, while HBV is more common in Asia and the Mediterranean.
A and E
The diagnosis of autoimmune hepatitis is based on the combination of four features: …
gender prediliction
autoantibodies, elevation of serum IgG, exclusion of other etiologies (e.g., viral hepatitis, drugs), and supportive histologic findings on liver biopsy.
Autoimmune hepatitis is a chronic, progressive hepatitis associated with genetic predisposition, autoantibodies, and therapeutic response to immunosuppression. There is a female predominance (78%).
The most common autoantibodies in type 1 autoimmune hepatitis are ANAs and anti–smooth muscle antibodies (ASMAs), while type 2 autoimmune hepatitis is characterized by anti-LKM1 autoantibodies.
There are two mechanisms of liver injury:
- x a dose-dependent phenomenon of the drug, or its metabolite, which predictably affects exposed individuals, a typical example being acetaminophen, which is the most common cause of acute liver failure in the United States. example?
- x which is not dosedependent, accounts for the majority of drug-induced liver injury, but typically occurs in a minority of individuals.
Direct hepatotoxicity
Idiosyncratic (hypersensitivity) response
A classic, dose-dependent, predictable hepatotoxin is acetaminophen, now the most common cause of acute liver failure necessitating transplantation in the United States.
Drug induced liver injury, examples?
Alcohol
Oral contraceptive
Vinyl chloride
Chemo agents
Some agents produce other patterns of injury.
Drugs like amiodarone (antiarrhythmic), tamoxifen (anti-estrogen), irinotecan (antineoplastic), and methotrexate (immunosuppressive) can cause a steatohepatitis-like pattern of injury.
Mitochondrial dysfunction caused by drugs such as tetracycline (antibiotic), valproic acid (anticonvulsant), and zidovudine (antiretroviral) can result in microvesicular steatosis.
Endothelial injury to sinusoids and central veins can be caused by cytotoxic agents (azathioprine, oxaliplatin), leading to sinusoidal obstruction syndrome (formerly called veno-occlusive disease).
In contrast to other chronic liver diseases, in which serum xc tends to be higher than serum x, in alcoholic liver disease serum x tend to be higher than serum x levels by a ratio of 2 : 1 or greater.
In contrast to other chronic liver diseases, in which serum ALT tends to be higher than serum AST, in alcoholic liver disease serum AST tend to be higher than serum ALT levels by a ratio of 2 : 1 or greater.
Consumption of x g/day of alcohol is considered to be the threshold for development of alcoholic liver disease, but may be lower in women.
80
- It may take 10 to 15 years of drinking for development of cirrhosis, which occurs only in a small proportion of chronic alcoholics.
- The pathologic effects of alcohol on hepatocytes include changes in lipid metabolism related to altered redox potential, injury caused by ROS generated by metabolism of alcohol by the P450 system, and protein adducts formed by acetaldehyde, a major metabolite of alcohol.
World Health Organization Criteria for the Metabolic Syndrome
Hemochromatosis is caused by excessive iron absorption, most of which is deposited in the liver and x, followed by the
liver, pancreas, myocardium, pituitary gland, adrenal gland, thyroid and parathyroid glands, joints, and skin