Gastro - Pathology Part 1 Flashcards
What is the name of the classical appearance found in a barium enema x-ray of a patient with colorectal cancer?
Apple core lesion
Salivary gland tumors are generally _____ (benign/malignant).
Benign
Where is the most common location for a salivary gland tumor?
Parotid gland
A patient presents with a painless, movable mass in a salivary gland. The mass is removed and found to be benign. It later recurs. What type of tumor is it?
Pleomorphic adenoma
Name the benign tumor composed of heterotopic salivary gland tissue trapped in a lymph node, surrounded by lymphatic tissue.
Warthin’s tumor
What is the most common malignant salivary gland tumor?
Mucoepidermoid carcinoma
Achalasia results from the failure of what process to occur?
Relaxation of the lower esophageal sphincter
In patients with achalasia, the lower esophageal sphincter cannot relax as a result of the loss of what source of innervation?
The myenteric (Auerbach’s) plexus
What is the most common presenting symptom of achalasia?
Dysphagia
In patients with achalasia, what test yields a classic diagnostic image?
Barium swallow
Describe the findings of achalasia on barium swallow.
Bird’s beak appearance: dilated proximal esophagus with tapering at the lower esophageal sphincter
Achalasia is associated with an increased risk of what malignancy?
Esophageal carcinoma
Secondary achalasia can result from what parasitic disease endemic to South America?
Chagas’ disease
What is the underlying pathophysiology of dysphagia associated with CREST?
There is esophageal dysmotility (poor peristalsis) and low esophageal pressure proximal to the lower esophageal sphincter
A patient with a history of asthma presents with a nonproductive cough and chest pain that is not associated with activity. It is worse with recumbency and is not relieved by inhalers or nitroglycerin. What is the likely diagnosis?
Gastroesophageal reflux disease
An alcoholic is brought into the emergency department vomiting copious amounts of blood. The condition this patient likely has causes painless bleeding from which vessels?
Submucosal veins in the lower one third of the esophagus, forming varices
A 45-year-old woman presents to the emergency department with a five-hour history of vomiting and retching. In the last hour, her vomitus was bloody and painful. What is the likely cause of her hematemesis?
Mallory-Weiss tears
A patient presents with chest pain after severe vomiting and is found to have substernal crepitus. What is the diagnosis?
Boerhaave syndrome (remember: “been-heaving syndrome”)
Ingestion of what compound classically causes esophageal strictures?
Lye; strictures are also seen with gastroesophageal reflux disease
Esophagitis is commonly associated with what three etiologies?
Reflux, infection, or chemical ingestion
Which three infectious agents can cause esophagitis?
Herpes simplex virus type 1, cytomegalovirus, and Candida
Plummer-Vinson syndrome has a triad of what symptoms?
Dysphagia due to esophageal webs, glossitis, and iron deficiency anemia
A patient is having difficulty swallowing. He has a swollen, tender tongue that appears smooth. Laboratory tests reveal iron deficiency anemia. What is the most likely diagnosis?
Plummer-Vinson syndrome
Is Barrett’s esophagus an example of glandular dysplasia, hyperplasia, neoplasia, or metaplasia?
Metaplasia
In patients with Barrett’s esophagus, there is a replacement of _____ _____ epithelium with _____ epithelium.
Nonkeratinized squamous; intestinal (columnar)
What causes Barrett’s esophagus?
Chronic acid reflux resulting in epithelial metaplasia
What specific malignancy is associated with Barrett’s esophagus?
Adenocarcinoma (remember: BARRett’s = Becomes Adenocarcinoma, Results from Reflux)
What are two behavioral risk factors for esophageal cancer?
Alcohol use and cigarette use
List four pathologic states of the esophagus that are risk factors for esophageal cancer.
Barrett’s esophagus, diverticuli, esophagitis, achalasia, and esophageal webs
In the United States, which type of esophageal cancer is most common?
Squamous cell carcinoma and adenocarcinoma of the esophagus have a roughly equal incidence
Worldwide, which type of esophageal cancer is most common?
Squamous cell carcinoma is most common
Squamous cell carcinoma is most common in which section(s) of the esophagus?
Upper and middle one third
Adenocarcinoma is most common in which section(s) of the esophagus?
Lower one third
What is a common history associated with esophageal cancer?
Progressive dysphagia that starts with dysphagia for solids and eventually includes liquids; also associated with weight loss, as is usually the case with malignancies
What symptoms are often associated with malabsorption syndromes?
Diarrhoea, steatorrhea, weight loss, weakness
List six examples of underlying etiologies for malabsorption syndromes.
Celiac sprue, tropical sprue, Whipple’s disease, disaccharidase deficiency, pancreatic insufficiency, and abetalipoproteinemia
Patients with celiac sprue develop autoantibodies to what substance?
Gluten (gliadin)
Celiac sprue primarily affects what part of the bowel?
Proximal small bowel
Tropical sprue can be treated with which class of drugs?
Antibiotics
Which section(s) of the gastrointestinal tract can be affected by tropical sprue?
The entire small bowel
What organism causes Whipple’s disease?
Tropheryma whippelii
The classic macrophages seen in Whipple’s disease stain positive with what stain? Where are they located?
Periodic acid-Schiff stain; the intestinal lamina propria and the mesenteric nodes
What nongastrointestinal symptoms are associated with Whipple’s disease?
Arthralgias as well as cardiac and neurological symptoms
The most common disaccharidase deficiency involves what disaccharidase?
Lactase
Are the villi in lactase deficiency normal or abnormal in appearance?
Normal; as opposed to celiac disease in which villi are blunted
What type of diarrhea is associated with disaccharidase deficiency?
Osmotic diarrhea
True or False? Self-limited lactase deficiency can occur following bowel damage from viral diarrhea.
True; lactase is located at the tips of intestinal villi, making it vulnerable to damage
What are three common causes of pancreatic insufficiency?
Cystic fibrosis, chronic pancreatitis, obstructing cancer
Pancreatic insufficiency causes the malabsorption of which macronutrient(s)?
Fat
Pancreatic insufficiency causes the malabsorption of which vitamins?
Vitamins A, D, E, and K
What is the pathophysiology of abetalipoproteinemia?
Decreased apolipoprotein B leads to decreased level of chylomicrons, which leads to decreased cholesterol and very-low-density lipoprotein in blood stream and accumulations of fat in enterocytes
What is the most common presentation for abetalipoproteinemia?
It usually presents in childhood with failure to thrive (malabsorption) and neurologic manifestations
Define celiac sprue.
Autoimmune damage to the small intestine caused by sensitivity to gluten, which damages the villi resulting in a decreased absorption surface; patient can present with vitamin deficiencies and steatorrhea due to decreased fat absorption
What region of the gastrointestinal tract is most affected by celiac sprue?
The jejunum
A patient presents with voluminous diarrhoea and a diffuse rash on his extensor surfaces; restriction of wheat resolves his diarrhoea and rash. What is the diagnosis of his rash?
Dermatitis herpetiformis resulting from celiac disease
Celiac sprue is associated with what type of malignancy?
T-lymphocyte lymphomas
What are two histological findings for celiac sprue?
Blunting of villi and the presence of lymphocytes in the lamina propria
What serum test is used to screen for celiac sprue?
Serum levels of antitissue transglutaminase antibodies; antigliadin antibodies are also seen in celiac disease
Why does celiac disease result in a malabsorption syndrome?
Antibodies destroy jejunal villi, decreasing absorption and causing diarrhea
_____ (Acute/chronic) gastritis is erosive, whereas _____ (acute/chronic) gastritis is nonerosive.
Acute; chronic
What are the two types of chronic gastritis?
Type A (in the fundus or body of the stomach) and type B (in the antrum)
Where does type A chronic gastritis occur?
Fundus/body
Where does type B chronic gastritis occur?
Antrum
List six causes of acute gastritis.
Nonsteroidal antiinflammatory drugs, alcohol, stress, uricemia, burns, and brain injury
What is the name for the acute gastritis that occurs in patients with severe burns?
Curling’s ulcer (remember: Burned by the Curling iron)
Cushing’s ulcer refers to the situation in which _____ _____ leads to acute gastritis.
Brain injury (remember: Always Cushion the brain)
Etiologically, type A (fundal) gastritis is best grouped in what category of diseases?
Autoimmune diseases
In type A (fundal) gastritis, there are autoantibodies to what?
Parietal cells
Type A (fundal) gastritis is characterized by what two pathologic states?
Pernicious anemia and achlorhydria (remember: AB pairing—pernicious Anemia affects gastric body)
Etiologically, type B (antral) gastritis is best grouped within what category of diseases?
Infectious diseases
Type B (antral) gastritis is caused by infection with what organism?
Helicobacter pylori
True or False? Acute gastritis carries an increased risk of gastric carcinoma.
False; chronic gastritis increases the risk of mucosa-associated lymphoid tissue lymphoma
A patient with rheumatoid arthritis, controlled by nonsteroidal antiinflammatory drugs, complains of dull stomach pain and is found to be anemic. What is the likely diagnosis and pathophysiology?
Nonsteroidal antiinflammatory drugs decrease prostaglandin E2 production, which, in turn, decreases gastric mucosa production. The resulting erosive gastritis can cause mild anemia through occult blood loss
By what mechanism do severe burns cause acute gastritis?
Curling’s ulcers cause a decrease in plasma volume, leading to a sloughing of gastric mucosa
How can brain injury lead to increased risk of gastric cancer?
Cushing’s ulcers cause an increase in vagal stimulation, causing increased acetylcholine, in turn increasing acid production by parietal cells
A 45-year-old patient with a history of Graves’s disease is found to be anemic and has an elevated mean red blood cell volume. She takes iron supplements daily and is no longer menstruating. What is the likely diagnosis?
Pernicious anemia caused by autoantibodies against parietal cells
What are the endoscopic findings associated with Ménétrier’s disease?
Massively enlarged gastric rugae
True or False? Ménétrier’s disease is a precancerous condition.
True
A patient undergoes endoscopy, which reveals a thickened gastric lining. Gastric biopsy reveals increased mucous cells and parietal cell atrophy. What condition does this patient likely have?
Ménétrier’s disease
What is the most common histological subtype of stomach cancer?
Adenocarcinoma
What organ is often the first to be affected by the metastases of stomach cancer?
The liver
What are risk factors for stomach cancer?
Nitrosamines (from smoked foods), achlorhydria, chronic gastritis, type A blood
What is meant when stomach cancer is termed “linitus plastica”?
Diffuse infiltrative cancer makes the stomach rigid
A patient presents with two months of fatigue and weight loss and mentions that he has notices a new bump above his collarbone. What diagnosis do you suspect?
The supraclavicular node suggests a metastasis from a stomach cancer
What is Krukenberg’s tumor?
Bilateral metastasis of gastric cancer to the ovaries.
A patient presents with dark leathery patches in the nape of his neck and in the axillae. What two things should you suspect?
Insulin resistance and stomach cancer
What is the histologic appearance of Krukenberg’s tumor?
Metastatic gastric adenocarcinoma often has mucus filled cells termed “signet ring cells”
What blood type is associated with increased incidence of stomach cancer?
Type A
What is the Saint Mary Joseph node and where is it located?
It is a palpable periumbilical metastasis
Peptic ulcer disease affects what two regions of the gastrointestinal tract?
The stomach (gastric ulcers) and the duodenum (duodenal ulcers)
A patient presents with stomach pain associated with meals. He is found to have ulcers in his gastrointestinal tract. Where are these ulcers likely located?
Stomach (remember: Gastric ulcer pain is Greater with meals)
What etiologic factor is associated with 70% of gastric ulcers?
Helicobacter pylori infection
A 69-year-old male with chronic back pain presents with stomach pain associated with meals. He is on metoprolol and naprosyn, smokes 2 packs/day, drinks 3 beers every other day, and has a negative urease breath test. What is the likely cause of his presenting symptom?
Chronic use of nonsteroidal antiinflammatory drugs leading to gastric ulcers
What is the pathophysiology of gastric ulcers?
Decreased mucosal production leading to destruction of tissue by gastric acid
Does the pain associated with duodenal ulcers increase, decrease, or remain the same with food?
Decrease (remember: Duodenal ulcer pain is Decreased with food)
Duodenal ulcers may lead to what constitutional symptom?
Weight gain; due to symptom relief with consumption of food
Is Helicobacter pylori implicated in duodenal ulcers?
Yes, almost 100% of duodenal ulcers are associated with Helicobacter pylori infection
Patients with duodenal ulcers tend to have hypertrophy of _____ _____.
Brunner’s glands
A patient complaining of stomach pain is found on endoscopy to have a lesion with irregular, raised margins. Does this finding indicate an ulcer or a malignancy?
This is likely a carcinoma; peptic ulcers have clean margins and have a “punched-out” appearance
List four common complications of peptic ulcers.
Bleeding, penetration into the pancreas, perforation, and obstruction
Recurrent duodenal ulcers due to increased gastric acid secretions and increased gastrin levels described which syndrome?
Zollinger-Ellison syndrome
What is hypothesized to be the etiology of Crohn’s disease?
Overactive response to normal intestinal flora leading to tissue damage
What general category of disease includes ulcerative colitis?
Autoimmune diseases
A 20-year-old patient presents with recurrent bloody diarrhea, weight loss, mouth ulcers, a painful rash on the extensor surfaces of her legs, and a perianal fistula. What is her likely diagnosis?
Crohn’s disease
Involvement of what part of the gastrointestinal tract favors a diagnosis of ulcerative colitis over Crohn’s disease?
Rectum
On colonoscopy, a patient with inflammatory bowel disease is found to have friable intestinal mucosa that abruptly stops in the midtransverse colon. There is no break in the involved portion. What is the likely diagnosis?
Ulcerative colitis
What type of inflammatory bowel disease tends to show skip lesions (noncontiguous areas of mucosal involvement)?
Crohn’s disease
What gastrointestinal disease can cause linear ulcers, fissures, and fistulas?
Crohn’s disease
What gastrointestinal disease shows noncaseating granulomas and lymphoid aggregates on microscopy?
Crohn’s disease (remember: for Crohn’s, a fat granny and an old crone skipping down a cobblestone road away from the wreck (rectal sparing)
What is the histologic appearance of ulcerative colitis?
Microscopy shows crypt abscesses and ulcers, but no granulomas
Is perianal disease a complication of Crohn’s disease, ulcerative colitis, or both?
Crohn’s disease
Is malabsorption a complication of Crohn’s disease, ulcerative colitis, or both?
Crohn’s disease; ulcerative colitis affects only the colon and thus does not cause malabsorption
Is toxic megacolon a complication of Crohn’s disease, ulcerative colitis, or both?
UC
A patient is newly diagnosed with irritible bowel syndrome. He is instructed to have screening colonoscopies starting 8 years from now. What is his likely diagnosis?
Ulcerative colitis; patients with ulcerative colitis must receive colonoscopies starting 8 years after initial diagnosis because of the increased risk of colon cancer
Are strictures a complication of Crohn’s disease, ulcerative colitis, or both?
Crohn’s disease; the strictures can lead to obstruction and require multiple resections of small bowel
What are the extraintestinal manifestations of Crohn’s disease?
Migratory polyarthritis, erythema nodosum, ankylosing spondylitis, uveitis, and immunologic disorders
What are the extraintestinal manifestations of ulcerative colitis?
Pyoderma gangrenosum, primary sclerosing cholangitis
The mucosal and submucosal inflammation with friable mucosal pseudopolyps and freely hanging mesentery of ulcerative colitis can cause what appearance on imaging?
The loss of haustra leads to lead pipe appearance
Name the three current treatments most commonly used for ulcerative colitis.
Sulfasalazine, infliximab, colectomy
Name the two treatments most commonly used for Crohn’s disease?
Corticosteroids and infliximab
Compare and contrast the layers of tissue involved in Crohn’s disease and ulcerative colitis.
Crohn’s disease exhibits transmural inflammation whereas ulcerative colitis demonstrates mucosal or submucosal inflammation only
What is the finding seen in this image and what is the associated disease?
String sign; Crohn’s disease
Name three findings of irritable bowel syndrome.
Abdominal pain relieved with defecation, change in stool frequency, change in appearance of stool
On colonoscopy, what is the most common finding of a patient with irritable bowel syndrome?
Normal mucosa; irritable bowel syndrome is not associated with structural abnormalities and is therefore a diagnosis of exclusion
What is the treatment for irritable bowel syndrome?
Since the symptoms fluctuate, it is important to reassess the patient’s chief complaint and treat the current symptoms (eg, diarrhea, constipation, both)
Since the symptoms fluctuate, it is important to reassess the patient’s chief complaint and treat the current symptoms (eg, diarrhea, constipation, both)
It starts as diffuse pain around the umbilicus then migrates to McBurney’s point
An 8-year-old child presents with 2 days of fever, vomiting, and severe abdominal pain. On examination, the right lower quadrant is very tender. She has a white blood cell count of 21,000. What is the treatment for her condition?
Surgery (appendectomy)
In elderly patients, what important condition must be included in the differential diagnosis of acute abdominal pain in addition to appendicitis?
Diverticulitis
A 21-year-old woman presents to the emergency room with diffuse periumbilical pain and nausea. Other than appendicitis, what condition should be ruled out?
Ectopic pregnancy with β-human chorionic gonadotropin test
A _____ is a blind pouch that leads off of the alimentary tract.
Diverticulum
What is the difference between a true diverticulum and a false diverticulum?
A true diverticulum contains three layers (mucosa, submucosa, and serosa) whereas a false diverticulum contains only two layers (mucosa and submucosa)
Diverticula are often due to weakness in the muscular wall caused by what?
Muscularis externa
Diverticula are most often found in what segment of the gastrointestinal tract?
The sigmoid colon
What is the etiology of diverticulosis?
Increased intraluminal pressure combined with focal weakness of the colonic wall
Diverticulosis is associated with what types of diets?
Low-fiber diets
True or False? Patients with diverticulosis usually have symptoms.
False; these patients are most often asymptomatic
List two symptoms that can be associated with diverticulosis.
Vague abdominal discomfort and painless rectal bleeding
Diverticulitis classically causes pain in what region of the abdomen?
The left lower quadrant
List the four most common complications that may be caused by diverticulitis.
Perforation, peritonitis, abscess formation, and bowel stenosis
A patient presents with fever, severe left lower quadrant pain, and a high white blood cell count. She is given antibiotics and defervesces. On hospital day 4, she notices that she is passing gas per her urethra. What complication likely occurred?
A fistula created by the infection between her colon and bladder leading to pneumaturia
What is the mainstay of treatment for diverticulitis?
Antibiotics although surgery may be required
Define Zenker’s diverticulum.
A herniation of mucosal tissue at the junction of the pharynx and the oesophagus
Is Zenker’s diverticulum a true or a false diverticulum?
False diverticulum; it contains only the mucosa and submucosa
What are symptoms of Zenker’s diverticulum?
Halitosis and dysphagia
Meckel’s diverticulum represents what embryonic structure?
Vitelline duct or yolk stalk
What type of ectopic tissue is sometimes found in a Meckel’s diverticulum?
Gastric and pancreatic tissue
What is the most common congenital anomaly of the gastrointestinal tract?
Meckel’s diverticulum
List four pathologic conditions that can be caused by a Meckel’s diverticulum.
Bleeding, intussusception, volvulus, and obstruction
Approximately what size is a typical Meckel’s diverticulum?
Two inches long
Where are Meckel’s diverticula typically located?
Within two feet of the ileocecal valve
In approximately what percentage of the population can Meckel’s diverticula be found?
2%
When in life do Meckel’s diverticula typically present?
During the first two years of life
What is intussusception?
The sliding of one segment of bowel into the bowel proximal to it, thereby shortening the bowel in a “telescope” fashion
What is a serious complication of intussusception?
Compromised blood supply leading to infarction and necrotic bowel
What are the etiologies of intussusception in adults and children?
A “lead point” or an intraluminal mass that, with peristalsis, can cause a part of the bowel to slide into the lumen of the adjacent bowel
Is intussusception found more commonly in adults or infants?
Infants
What is volvulus?
The twisting of a portion of bowel around its mesentery
What are two common locations of volvulus?
Sigmoid colon and cecum
Why does volvulus have a predilection for specific parts of the bowel?
Volvulus tends to occur in locations with redundant mesentery
An 82-year-old woman presents with acute onset abdominal pain, obstipation, and a large segment of air-filled bowel in the right upper quadrant on plain film. Stool is occult blood negative. What is the likely diagnosis?
Caecal volvulus
In patients with Hirschsprung’s disease, what is noted on intestinal biopsy?
Lack of ganglionic cells that allow relaxation of the affected bowel
Hirschsprung’s disease results from the failure of what process?
Neural crest cell migration
How does Hirschsprung’s disease typically present?
Inability to pass meconium after birth or chronic constipation in a child
In patients with Hirschsprung’s disease, where is the dilated segment of the colon relative to the aganglionic segment?
Proximal
In patients with Hirschsprung’s disease, which segment of the colon is constricted?
The aganglionic segment
A two-week-old boy does not pass meconium at birth. He is referred to a gastroenterologist who finds increased resting pressures on anal manometry. The mother remarks that she had abnormal prenatal genetic testing. What is the karyotype of this patient?
Trisomy 21
A newborn boy has been vomiting bilious stomach contents since birth and his abdomen has become progressively distended. What condition is likely in this newborn?
Duodenal atresia
Duodenal atresia is associated with what sign on imaging?
Double bubble sign
Duodenal atresia is due to the failure of _____ of small bowel during development.
Recanalization
Duodenal atresia is associated with what chromosomal abnormality?
Down’s syndrome
A newborn boy fails to pass meconium at birth. Rectal exam and anal manometry is normal. His older brother died from severe pneumonia. What is this patient’s underlying genetic disorder and diagnosis for his chief complaint?
Cystic fibrosis; meconium ileus
Which patients are most at risk for necrotizing enterocolitis?
Premature neonates because of their decreased immunity
True or False? Necrotizing enterocolitis affects only the colon.
False; the colon is usually involved, but this condition can involve the entire gastrointestinal tract
An infant born at 25 Weeks develops feeding intolerance and a distended abdomen and grows gram-negative rods from blood culture. What is the underlying disease?
Necrotizing enterocolitis followed by perforation and sepsis
Ischemic colitis typically affects _____ (neonates/children/adults/the elderly).
The elderly
Where does ischemic colitis commonly occur?
The splenic flexure; it is a watershed area between the superior mesenteric artery and inferior mesenteric artery circulation and has poor blood flow
An 80-year-old man with coronary artery disease presents with 6 months of weight loss due to pain after eating. What do you suspect?
Ischemic colitis associated with low blood flow to intestine; the splenic flexure is a watershed site and thus is most affected by low blood flow states
What is a common complaint of patients with ischemic colitis?
Pain after eating; increased metabolic demand in intestine and inability to appropriately increase blood flow leads to an ischemic state
Adhesions cause _____ (acute/chronic) bowel obstruction.
Acute
What is the most common cause of adhesions?
Abdominal surgery
What test can confirm a diagnosis of angiodysplasia?
Angiography
Where is angiodysplasia typically found in the gastrointestinal tract?
Cecum, terminal ileum, ascending colon
Angiodysplasia causes what symptom?
Bleeding from tortuous and dilated vessels
Is angiodysplasia more common in a younger population or in the elderly?
Elderly
The more villous the colonic polyp, the _____ (more/less) likely it is to be malignant.
More (remember VILLOUS = VILLainOUS)
Where in the colon are polyps most commonly found?
Rectum and sigmoid colon
A mother brings in her son for bleeding per rectum. Exam shows a single rectal polyp and barium enema shows no other pathology. What is the most likely natural history of this lesion?
A single juvenile polyp; it has no malignant potential if it is truly the only one
Is a child at increased risk for cancer if he/she has multiple polyps?
Yes, the child is at increased risk of adenocarcinoma
A patient has a number of hamartomas through his gastrointestinal tract and dark patches around his mouth and palms. What is the likelihood that his daughter will have his disease?
50%. This patient has Peutz-Jeghers syndrome, an autosomal dominant disorder
A patient being treated for colon cancer is found to have multiple hamartomas throughout the gastrointestinal tract and hyperpigmentation of the mouth and genitals. What is the diagnosis?
Peutz-Jeghers syndrome
What is the most common nonneoplastic polyp and where are they most commonly found?
hyperplastic; rectosigmoid colon
What is the ranking of colorectal cancer among the most common cancers?
Colorectal cancer is the third most common cancer
Which autoimmune disease is a risk factor for colorectal carcinoma?
Ulcerative colitis
What is the most common presentation of a distal colonic tumor?
Obstruction, colicky pain, hematochezia
What is a common presentation of right-sided colon cancer?
Dull pain, iron-deficiency anemia, fatigue
What are risk factors for colorectal cancer?
Age, genetic syndromes, family history, irritable bowel disease, tobacco use, villous adenomas
At what age is screening for colorectal cancer typically initiated?
50 years
What two tests play the most important role in colorectal cancer screening?
Stool occult blood testing and colonoscopy
What does an apple-core lesion indicate?
Colorectal cancer on a barium enema X-ray
What is a nonspecific serum tumor marker for colorectal cancer?
Carcinoembryonic antigen (CEA)
