The GI Tract Flashcards
What characterizes Achalasia?
The failure of the LES to relax in response to swallowing
The absence of peristalsis in the body of the esophagus
Dilated esophagus (depletion of ganglion cells in myenteric plexuses)
How does a ring differ from a web?
webs are thin mucosal membranses that project into the lumen of the esophagus. Rings are thicker and contain smooth muscle
What are complications of Pummer-Visnon Syndrome?
P-V Syndrome (web, lesions, anemia) complications include: Carcinoma of the Oropharynx and Upper Esophagus
What’s most common GI complication of Scleroderma?
Esophageal dysfunction. LES especially is impaired so that the lower esophagus and upper stomach are no longer distinct functional entities.
Some patients may have a lack of peristalsis in the entire esophagus.
Where is the defect in a paraespophageal hiatal hernia?
It is in the diaphragmatic connective tissue membrane that defines the esophageal hiatus
What are symptoms of hiatal hernia? why?
Heartburn andd Regurgitation because of the reflux of gastric contents (due to LES incompetence; also symptoms are exacerbated when patient is recumbent)
What are the complications of large hiatal hernias?
Gastric Volvulus
Intrathoracic Gastric Dilation
Describe an Esophageal Adenocarcinoma
1) Symptoms
2) Groth pattern
- Symptoms: Dysphagia, pain, occasionally bleeding
- They tend to grow into the lumen of the esophagus. The affected region of the esophagus is typically indurated and ulcerated, (causing plain and bleeding)
What are the risk factors for squamous cell carcinoma of the esophagus?
Chronic Alcoholism Tobacco Use Diets lacking fresh fruits Aniline Dye Exposure Chronic Esophagitis Congenital disorders of the esophagus (ex. Plummer-Vinson Syndrome)
In Candida Esophagitis, what are the pseudomembranes composed of ?
Fungal mycelia
Fibrin
Necrotic Debris
In Candida Esophagitis, what are the complications? symptoms?
Involvement of deeper layers of the esophageal wall can lead to disseminated candidiasis, as well as fibrosis, which is sometimes severe enough to create esophageal stricture
Symptoms include dysphagia and odynophagia (pain on swallowing)
What is a key feature of herpetic esophagitis?
Mucosal vesicles
When and where do esopohageal varices most often occur?
Where: beneath the mucosa, lower third of the esophagus
When: Most often in the setting of portal HTN , secondary to cirrhosis
What is the key feature in the pathogenesis of Acute Hemorrhagic Gastritis?
The breakdown of the mucosal barrier, which permits acid-induced injury. Mucosal injury causes bleeding from superficial erosions.
What are some more sever complications of Acute Hemorrhagic Gastritis?
Defects in the mucosa may extend in to the deeper tissues to form an ulcer.
the necrosis is accompanied by an acute inflammatory response and hemorrhage, which may be severe enough to result in exsanguination and hypovolemic shock.
What substances when ingested are associated with Acute ersoive gastritis?
Aspirin
NSAIDs
Alcohol
Ischemic Injury
What are features of Autoimmune Gastritis?
Chronic Diffuse Atrophic Gastritis
Antibodies to PARIETAL CELLS
Antibodies to Intrinsic Factor
(Immunological Destruction leads to interfernce of B12 absorption and Pernicious Anemia : Megaloblastic cells- asynchrous maturation between nucles and cytoplasm of Bone Marrow precursors)
G- cell Hyperplasia (leading to Increased serum gastrin )
What is the most common gastritis and what are the associated risks?
H. Pylori Gastritis (chronic inflammation of stomach antrum and body)
It is a Risk factor for GASTRIC ADENOCARCINOMA and LYMPHOMA
How does a Peptic Ulcer look?
Punched out
Rounded
Hemmorrhagic (if erosion through arteries cause bleeding and iron-deficieny anemia)
What characterizes Zollinger-Ellison Syndrome?
Unrelenting Peptic Ulceration (stomach, duodenum, or proximal jejunum) by the action of tumor-derived gastrin by a Gastrinoma.
What are the most frequent presenting symptoms of a adenocarcinoma of the stomach?
Weight loss, associated with nausea and anorexia usually
Many patients complain of epigastric pain- a symptom that mimics benign gastric ulcer disease, and is often relieved by antacids or H2 receptor antagonists
Describe a gastric cancer on gross examination
Polypoid or Fungating or Ulcerated Mass
or Diffuse infiltration of the stomach wall
How does linitis plastica develop?
The diffuse adenocarcinoma tumor cells induce extensive fibrosis in the submucosa and muscularis of the cell wall.
Poor prognosis!
Why are signet ring cells named so?
Intracellular mucin displaces the nuclei to the periphery of the tumor cells
What is Menetrier Disease?
Hyperplastic Hypersecretory Gastropathy (rare) characterized by enlarged rugae.
The folds of the greater curvature in the fundus and body of the stomach (occasionally in the antrum) are increased in height and thickness forming a convulated brain-like surface.
What are the two forms of Menetrier Disease? and cause?
Childhoodform (CMV infection) Adult form (overexpression of TGF-alpha)
What abnormality often acccompanies Menetrier disease?
It is often accompanied by a severe loss of plasma proteins (including albumin) from the altered gastric mucosa.
Where are GI Stromal Tumors (GIST) derived from?
The Pacemaker cells of Cajal
They include the vast majority of mesenchyme-derived stromal tumors of the entire GI tract
What are the gross and microscopic characteristics GI Stromal Tumors (GIST)?
They are usually submucosal and covered by intact mucosa
Microscopically, the tumors show spindle cells with vacuolated cytoplasms
What’s the treatment of GIST?
They are of low malignant potential and are removed surgically
What is the most common extranodal lymphoma? what is its most common subset? prognosis?
The most common form of extranodal lymphoma is GASTRIC LYMPHOMA (20% of such tumors).
It has a 45% 5 -year survival- better prognosis thatn gastric carcinoma
Most gastric lymphomas are low-grade B-cell neoplasms of the MALToma (mucosa-associated lymphoid tissue) type, which arise in the setting of chronic H. Pylori gastritis with lymphoid hyperplasia. (some of thees lymphomas regress after eradication of the infection)
What are the clinical symptoms of gastric lymphoma?
The same as gastric carcinoma:
Weight loss, dyspepsia, and abdominal pain
Bezoars are…
Foreign boides in the stomach that are composed of food or hair that have been altered by the digestive process
Trichobezoar
Hairball
It can grow by accretion to form a complete cast of the stomach
Strands of hair can extend into the bowel as far as the transverse colon
Trichotillomania
aka. Rapunzel Syndrome: seen in long-haired girls or young women who eat their own hair as a nervous habit
Where are perforating ulcers commonly found?
The Duodenum
it is a rare complication of peptic ulcer disease
What is the characteristic microscopic finding of Carcinoid tumors?
Nueroendocrine cells that show considerable nuclear uniformity
Where are Carcinoid Tumors most commonly located?
Submucosa of the intestines
- Appendix
- Termnal Ileum
0 Rectum
What are the clinical features of Carcinoid Tumors
They are low-grade malignant neoplasms that release hormones(Serotonin, Bradykinin, Histamine) into venous blood causing FLUSHING, BRONCHIAL WHEEZING, WATERY DIARRHEA, and ABDOMINAL COLIC
What are some severe manifestations of Carcinoid Tumors?
Release of tumor secretions from hepatic metastases leads to the formation of fibrous plaques in the tricuspid and pulmonic valves (possibly resulting in Tricupsid Insufficiency or Pulmonic Stenosis)
What are the features of Peutz-Jeghers Syndrome?
- It is Autosomal Dominant
- Intestinal hamartomatous polyps and mucocutaneous melanin pigmentation(probably evident of face, buccal mucosahands, feet, and perianal and genital regions.
- Polyps are hamartomatous with characteristic branching network of smooth muscle fibers continous with the muscularis mucosa that support grandular epithelium of polyp
Describe a hyperlpastic polyp on the micro level
- They are small, sessile ucosal exrescences that display exaggerated crypt architecture
- The crypts are elongated and may exhibit cystic dilations.
- The epithelium is composed of goblet cells and absorptive cells without any dysplasia or nuclear atypia
Describe a Tubular Adenoma on the micro level
They are typically smooth-surface lesions, usually less than 2 cm in diameter and often have a stalk.
They have closely paced epithelial tubules, which may be uniform or irregular with excessive branching. can be psuedostratified epithelium with hyperchoromicatic nuclei.
Does Adeoncarcinoma have dysplastic features? Tubular adenoma?
Adenocarcinoma: Yes
Tubular Adenoma: Yes or No (it can develop)
Describe a villous adenoma macro and microscopically
Macro: Large, broad-based, elevated lesions that display a shaggy, cauliflower-like surface.
Micro: Thin, tall, fingerlike processes, which superficially resemble the villi of small intestine.
What is the most common malignant disorder affecting the peritoneum?
Metastatic Carcinoma
Which carcinomas are likely to seed the peritoneum?
Ovarian, gastric, and pancreatic carcinomas
Any intra-abdominal carcinoma can spread to the peritoneum
How does Metastatic carcinoma present to the abdomen?
It presents int he form of multiple serosal nodules and ascites fulid that contains malignant cells
Waht GI symptoms are associated with Kaposi Sarcoma?
GI bleeding, obstruction, and malabsorption
What characterizes Ulcerative Colitis?
Inflammation of the large intestine with chronic diarrhea and rectal bleeding.
It is a disease of the MUCOSA and has patterns of remission and exacerbation with possible systemic and local complications
To which part of the GI tract is Ulcerative Colitis limited to?
The colon and rectum
What GI disorder is often caused by antibiotic therapy?
Pseudomembranous colitis ( the mucosal surface of the colon is covered by raised irregular exudative PLAQUES composed of necrotic debris and an acute inflammatory exudate.
C. Difficile’s exotoxins cause intestinal necrosis with superficial ulcers covered by a thick fibropurulent exudate)
How does Crohn disease typically affect the colon?
In a patchy distribution with transmural inflammation
What are the complications of Ulcerative Colitis?
Toxi Megacolon
Carcinoma (Including colorectal adenocarcinoma- usually after 10 yrs of diseaseyt5)
What are the complications of Crohn Disease?
Malabsorption
Calcium Oxalate Nephrolithiasis
Fistula Formation
Carcinoma(if colonic disease is present)
What characterizes Primary Sclerosing Cholangitis?
Inflammation and Obliterative fibrosis of intrahepatic and extrahepatic bile ducts.
A beaded biliary tree represents sporadic strictures (on radiography)
70%patients with PSC have longstanding ulcerative colitis (4% for vice versa)
What are common skin, liver, and other complications of Ulecerative Colitis?
Uveitis
Skin: Erythema Nodosum and Pyoderma Gangrenosum
Liver: Pericholagnitis and Fatty Liver
How do most cases of peritonitis develop?
Most often caused by bacteria that enter the abdominal cavity from a perforated viscus or through an abdominal wound.
Spontaneous bacterial peritonitis can occur in children without an obvious perforation. Especially children with nephrotic syndrome and a systemic infection that seeds the ascitic fluid with bacteria.
If a bacterial peritonitis occurs spontaneously, it is probably due to cirrhosis
Where are diverticula most common?
the SIGMOID colon
What are sercious complications of diverticula?
Peritonitis and Sepsis
What organism is usually associatied with pseudoappendicitis? What are the symptoms?
Yersinia enteroclitica.
The lymph nodes show a granulomatous inflamation. Other symptoms are diarrhea, reactive arthritis, erythema nodosum, and septicemia.
It causes Mesenteric Adenitis
What characterizes an Anorectal Malformation?
Classification is based on the relation of the terminal bowel to the levator ani muscle
