EXAM #1: GI NEOPLASIA Flashcards
What type of tumor is the most common in the GI tract?
Adenocarcinoma
What site is most commonly affected by neoplasia in the GI system?
Colon
What are the most common benign tumors of the small bowel?
1) Adenomas
2) Mesenchymal tumors i.e. GISTs
What are the most common malignant tumors of the small bowel?
1) Adenocarcinoma
2) Carcinoids
What genetic conditions predipose patients to carcinomas of the small bowel?
1) Familial Adenomatous Polyposis (FAP)
2) Gardner’s Syndrome
What is an adenoma?
Neoplastic proliferation of glands
Where are adenomas in the small bowel most common?
Amupulla of Vater –this is the union of the pancreatic duct and common bile duct
What are the clinical features of adenomas?
- Seen in middle age
- Cause occult blood loss
- Can precipitate obstruction/ intussusception
Where do most adenocarcinomas occur in the small bowel?
Duodenum
What type of pattern do adenocarcinomas grow in?
Napkin ring i.e. encircling
What is the major non genetic risk factor for adenocarcinomas?
Crohn’s Disease
What is a polyp?
Benign mass protruding from the mucosa into the lumen of the gut
Are most polyps malignant or non-malignant?
Non-malignant
What are the two types of polyps seen in the colon?
1) Adenomatous
2) Hyperplastic
What is a hyperplastic polyp?
Hyperplasia of glands
What is a Hamartomatous polyps?
A polyp formed by disorganized normal tissue (seen mostly in kids; therefore, called a “Juvenile Polyp”)
What is an inflammatory polyp?
This is an alternate name for pseudopolyps seen in Ulcerative Colitis
What type of polyp is most common?
Hyperplastic
Where do most hyperplastic polyps occur?
Rectosigmoid region
What are harmatomatous polyps called in kids?
Juvenile polyps
What are harmatomatous polyps called in adults?
Retention polyps
What are Peustz-Jegher’s polyps?
Hamartomatous polyps seen in Peutz-Jegher’s Syndrome
- Polyps seen throughout the GI tract (vs. solitary)
What is Peutz-Jegher’s Syndrome?
- Autosomal Dominant disorder
- Characterized by:
1) Mucocutaneous pigmentation around the mouth (freckles around the mouth)
2) Multiple hamartomatous polyps
What gene is mutated in Peutz-Jegher’s Syndrome?
STK11
What are the hamartomatous polyps of Peutz-Jegher’s Syndrome composed of?
1) Connective tissue
2) Smooth muscle
What are patients with Peutz-Jegher’s Syndrome at risk for?
- Intussusception
- Cancer
1) Colorectal
2) Breast
3) GYN
What are the four different types of adenomas?
1) Tubular
2) Tubulovillous
3) Villous
4) Serrate
What is the most common type of ademona? What is the association with carcinoma?
Tubular
Lowest neoplastic potential b/c of “buffering” of the stalk*
Which type of adeoma is most associated with carcinoma?
Villous adenomas
What are the three risk factors that confer greatest potential to transition from adenoma to carcinoma?
1) Size greater than 2cm
2) Sessile (flat) growth
3) Villous histology
What is the cancer risk associated with Tubulovillous Adenomas?
Intermediate
Associated with the villous portion
When is there highest concern for cancer in villous adenoma?
Progression to greater than 4 cm
What type of adenomas are most associated with being symptomatic? What is the presentation?
Villous adenomas:
- Overt rectal bleeding causing
- Hyponatremia
- Hypokalemia
What is the only adequate treatment for pedunculated or sessile adenoma?
Complete resection
What is carcinoma in situ?
Neoplastic cells that have NOT breached the basement membrane
What is the Adenoma-Carcinoma Sequence?
1) APC mutations= increased risk
2) K-ras mutation= adenoma
3) p53 and increased COX= carcinoma
What are the risk factors for colorectal carcinoma?
1) Increased age
2) Prior colorectal CA or polyps
3) UC/ CD
4) Poor diet
What environmental factors may be protective in colorectal carcinoma?
NSAIDs esp. ASA b/c of COX inhibition
Where to colorectal cancers commonly metastasize?
Liver
Iron-deficiency anemia in an older male is ____ until proven otherwise?
Colorectal carcinoma
What side of the colon is commonly implicated in colorectal carcinoma leading to anemia?
Right-sided
What familial syndromes cause colorectal cancer?
1) Classic FAP
2) Attenuated FAP
3) Gardner Syndrome
4) Turcot Syndrome
FAP= Familial Adenomatous Polyposis
What is Classic Familial Adenomatous Polyposis?
- AD
- Avg. onset at 25 y/o
- Causes thousands of polyps
What gene is implicated in Classic FAP?
APC on chromosome 5q21
What treatment is available for patients with Classic FAP?
Total colectomy (preventative)
What is Attenuated FAP?
- Delayed appearance (50 y/o)
- Fewer polyps
- Proximal colon
What mutations are associated with Attenuated FAP?
APC and MUTYH
What is Gardner Syndrome?
Classic FAP +
- Osteomas of skull/ mandible
- Epidermal cysts
What is Turcot Syndrome?
FAP + CNS tumors
What is HNPCC?
Hereditary Nonpolyposis Colorectal Cancer
- Genetic mutation predisposes to carcinoma
- NO adenoma first
What is the eponym for HNPCC?
Lynch Syndrome
What gene is involved in HNPCC?
MSH1 and MSH2
- DNA mismatch repair enzymes
- DNA microsatellite instability
What cancers are seen in HNPCC?
Colorectal cancer WITHOUT polyps + cancer outside the colon
Outline the associations with left-sided carcinoma and right sided colorectal carcinoma.
Left=
- “Pencil thin” stool
- Napkin ring
- APC related mutations
Right=
- Iron deficiency anemia/occult bleeding
- Raised lesions
- MSH mutations
In colon cancer, what is mucin production associated with?
Poor prognosis
What is the relationship between lymph node mets and prognosis in colorectal cancer?
- Less than 3 nodes= better prognosis
- More than 3 nodes= poor prognosis
What is Stage TI colorectal cancer?
Invasion of the submucosa
What is Stage TII colorectal cancer?
Invasion of the muscularis propria
What is Stage TIII colorectal cancer?
Penetration through the bowel wall
What is Stage TIV colorectal cancer?
Spread to other organs
In the Modified Duke’s Staging scheme for colorectal cancer, what indicates a better prognosis? Poor prognosis?
A= good B= bad
What is a carcinoid tumor?
- Neuroendocrine cell tumor
- Forms a polyp most common in small bowel
- Produces 5-HT and bradykinin
What is Carcinoid Syndrome? What is Carcinoid Syndrome associated with?
Carcinoid syndrome is the process initiated by systemic 5-HT; associated with liver mets b/c this allows 5-HT to bypass liver MAO
What are the symptoms of Carcinoid Syndrome?
Flushing
Bronchospasm
Diarrhea
What is Carcinoid Heart Disease?
Carcinoid Syndrome that causes right-sided valvular fibrosis
- Tricuspid valve regurgitation
- Pulmonary stenosis
What are the three types of GI Lymphomas?
1) MALToma
2) Sprue-associated
3) Mediterranean
What is Mediterrranean Lymphoma?
B-cell lymphoma in patients of Mediterranean ancestry
What is the hallmark of Mediterranean Lymphoma?
Abnormal IgA heavy chain synthesis
What type of Lymphoma is associated with Spure-associated Lymphoma?
Intestinal T-cell Lymphoma
- Seen in patients with longstanding malabsorption
Worst prognosis
What is acute appendicitis?
Inflammation of the appendix
What is the most common cause of appendicitis?
Impacted fecolith
What are the hallmark symptoms of acute appendicitis?
Anorexia
RLQ pain
N/V
Fever
What is the classic immune cell associated with acute appendicitis?
Neutrophils
What is the most common tumor of the appendix?
Carcinoid
What are the three mucus related tumors of the appendix? Which has the worst prognosis?
1) Mucocele
2) Mucinous cystadenoma
3) Mucinous cystadenocarcinoma
