GIT: Intestinal Tumors

Question 1

describe juvenile polyp (hamartomatous polyp)

Answer 1

• aka retention polyp
• common in children < 5 years but also seen in adults
• rectum is most common site
• rarely juvenile polyposis syndrome (AD)
• sporadic single polyps; NO MALIGNANT POTENTIAL
• juvenile polyposis syndrome: increased risk of malignancy
• also seen in Cowden and Bannayan-Ruvacalba-Riley syndromes (PTEN mutations)

Question 2

juvenile polyps most commonly occur in the ____ and there is no chance for ____ unlike _____

Answer 2

juvenile polyps most commonly occur in the rectum and there is no chance for malignancy unlike juvenile polyp syndrome (AD) where there is an increased risk for malignancy

Question 3

describe the structure and histology of a juvenile polyp

Answer 3

usually 1-3 cm, lobulated with stalk

• histology:
  
  • expanded lamina propria
  • abundant cystically dilated glands
  • inflammatory cells may be present

Question 4

describe Peutz Jegher polyp (hamartomatous polyp)

Answer 4

• sporadic or syndromic forms
• PJ syndrome:
  
  • AD
  • multiple polyps in whole GIT
  • melanotic pigmentation in mucocutaneous areas, lips, perioral areas, face, genitalia and palms
• arborizing network of smooth muscle between glands
• glands are lined by non-dysplastic epithelium rich in goblet cells
• risk of developing carcinomas of pancreas, breast, lung, ovary and fetus

Question 5

name the condition

Answer 5

Peutz Jegher Polyp

Question 6

describe the image

Answer 6

Peutz Jegher Polyp

arborizing network of smooth muscle between glands

Question 7

the risk of an adenoma becoming malignant increases with… (4 things)

Answer 7

1. polyp size (most important criteria)
2. severity of dysplasia
3. villous architecture
4. 3 or more adenomasb

Question 8

describe familial adenomatous polyposis (FAP)

Answer 8

• genetic defect in APC gene (chr. 5)
• colorectum: small intestine and stomach
• typically 500-2500 tubular adenomas
• attenuated FAP: fewer than 100
• prophylactic total colectomy due to high risk of colorectal cancer
• Gardner syndrome:
  
  • tubular adenomas with osteomas, desmoid tumors, epidermal cysts
• Turcot syndrome
  
  • tubular adenomas with CNS gliomas

Question 9

describe right-sided vs. left-sided colon cancers

Answer 9

• right-sided:
  
  • fatigue, weakness and iron deficiency anemia (bulky and bleed easily)
• left-sided
  
  • altered bowel habits

Question 10

____ is the tumor marker for colon cancers

Answer 10

CEA is the tumor marker for colon cancers

Question 11

list the 3 settings in which neuroendocrine tumors occur in the stomach (carcinoid)

Answer 11

• type I: autoimmune gastritis
  
  • gastric atrophy and achlorhydria
  • hypergastrinemia leads to ECL cell hyperplasia
  • may be multiple, usually follows benign course
• type II: gastrinoma (Zollinger-Ellison syndrome)
  
  • usually in MEN 1 syndrome, hypergastrinemia
• type III: sporadic
  
  • more aggressive than other types

Question 12

____ is the most common site in the GIT for neuroendocrine tumors

Answer 12

small intestine and appendix is the most common site in the GIT for neuroendocrine tumors

• can metastasize widely leading to carcinoid syndrome when liver involved
  
  • wheezing, diarrhea, flushing
  • 5HT elevated (right side of heart: fibrosis)