Lower GI Neoplasia (Quiz 2) Flashcards
what is the most common of malignant small bowel tumors
- carcinoid
what is a carcinoid tumor
- rare, well-differentiated neuroendocrine tumor
most common location for carcinoid tumor
- ileum
symptoms if a carcinoid tumors obstructs the bowel
- desmoplasia - growth of fibrous or connective tissue
- intussusception
what is carcinoid syndrome
- metastasis of carcinoid tumor to the liver
symptoms of carcinoid syndrome
- flushing
- diaphoresis
- diarrhea
- wheezing
- hypotension
appendices carcinoids usually occur where
- tip of appendix
histology of carcinoid syndrome
- bland tumor cells
- salt and pepper chromatin
- no large nucleoli
distinguishing factor of carcinoid tumor cells
- synaptophysin positive (stains red)
what polyps have no malignant potential and no increased risk for CRC
- hyperplastic polyps
what is the most common polyp in the large bowel
- hyperplastic polyp
size of hyper plastic polyps
- most less than 3 mm in diameter
gross pathology of hyperplastic polyps
- small sessile polyps
- slightly pale
histopathology of hyperplastic polyps
- serrated crypts
- decreased goblet cells
which cells are premalignant and all dysplastic
most colon cancers arise from this
- colonic adenomas
two growth patterns of polyps
which is easier to clip
- sessile
- pedunculated - easier to clip because it’s basically on a a pedestal
which architecture of an adenomatous polyp is the most common type with adenomatous epithelium arranged in closely-packed branching tubules having a cerebriform appearance at low power
- tubular
which architecture of an adenomatous polyp is where adenomatous epithelium takes the form of straight, elongated finger-like fronds extending from the muscular mucosal to the luminal surface
- villous
which architecture of an adenomatous polyp is a mixture of tubular and villous architecture
- tublovillous
what makes epithelium adenomatous
- pleomorphic colonic epithelium
- nuclear pseudostratification
- loss of cytoplasmic mucin
what is a polyp that grossly appears benign but is later found by histologic examination to contain cancer
- adenocarcinoma arising in a polyp
symptoms of colon cancer
- asymptomatic
- obstruction
- bleeding
- weight loss
- pencil thin stool
- iron deficiency anemia
what kind of lesion do we see with colon cancer
- apple core lesion
in the setting of a newly recognized iron deficiency anemia, what is the biggest concern
what is the test to rule out?
- colorectal cancer
- colonoscopy
tumors in the right colon are usually
- polypoid
- fumigating exophytic masses
tumors involving the left colon are more
- annular lesions
- apple-core lesions
- bowel obstruction
histology of colorectal carcinoma
- adenocarcinoma within desomoplastic stroma
- invades bowel wall
nuclei of tumor cells in colorectal carcinoma
- oval or rounded nuclei
chromatin of tumor cells in colorectal carcinoma
- clumped chromatin
- nuclear polymorphism
nucleoli of tumor cells in colorectal carcinoma
- large or irregular
mucin secretion of tumor cells in colorectal carcinoma
- minimal to abundant
- signet ring pattern occurs
what happens if KRAS or BRAF mutations are present in colorectal carcinoma
- patient resistant to anti-EGFR therapies
what happens if MSI-high in colorectal carcinoma
- patient resistant to 5-fluorouracil therapy
genetics of familial adenomatous polyposis
mutation where
chance of cancer
- autosomal dominant
- mutation of APC gene
100% chance of cancer
Peutz-Jehgers Syndrome symptoms
- multiple GI hamartomatous polyps
- pigmented spots on lips and buccal mucosa
genetics of Peutz-Jehgers Syndrome
mutation where
- autosomal dominant
- mutation in STK11 gene
