Lec 31 Flashcards
What features of dysplasia in colorectal adenoma?
- elongated, darkly stained nuclei that are crowded/overlapping
- blurred distinction between cells; reduced or excessive mucin
What is definition of a colorectal adenoma?
benign neoplasm consisting of dysplastic colorectal epithelium
Are left or right sides polyps more likely to cause symptoms?
left sided b/c the lumen is smaller so more likely to cause obstruction; also blood in stool more visible from distal colon
What is pedunculated vs sessile polyp?
pedunculated = permanent stalk created sessile = broad based mound
What percentage of CRCs are due to the adenoma-carcinoma sequence?
75%
What is potential presentation of huge carpet-like adenoma?
water diarrhea, hypokalemia
What is a hyperplastic polyp? histology?
tiny sessile polyp; usually in rectosigmoid [left] colon
has serrated elongated crypts that are not dysplastic
no malignant potential
What mutation associated with sessile serrated polyp?
BRAF mutation
Where are sessile serrated polyps usually located?
usually in right colon
What is histology of cessile serrated polyp?
- serrated along entire length
- flat base resembling inverted letter T or L
What is most important prognostic indicator of CRC?
tumor stage
What are 2 parameters of tumor stage?
- depth of tumor invasion
2. lymph node metastases
What is a juvenile polyp?
occurs in children
often in recutm
spherical polyp; may cause rectal bleeding or obstruction
What is juvenile polyposis syndrome?
autosomal dominant
have multiple juvenile polyps and increased risk of adenocarcinoma
What is a hamartomatous polyp?
consists of lobules of non-dysplastic colonic epithelium surrounded by smooth muscle
not clinically significant as a single polpy
What is peutz jeghers syndrome?
autosomal dominant; multiple non-moalignant hamartomas throughout GI tract + hyperpigmented mouth, lips, hands
increased risk of CRC
Why do most CRCs have hard consistency?
desmoplastic reaction of tissue around the cancer
compare to adenomas = soft
What are mucinous adenocarcinomas?
grossly gelatinous = cancer cells floating in pools of mucin
Who gets mucinous adenocarcinoma of the colon?
very young and very old
IBD
lynch syndrome
Is pronosis of mucinous adenocarcinoma better or owrse than other CRCs?
same
Are microsatellite unstable cancers have better or worse prognsosis?
better prognosis
What stain can you use for microsatellite unstable cancers?
CD3 immunostain –> MSI cancers often hve lymphocytes intermingled with tumor cells
What is most common type of carcinoid tumor?
appendiceal carcinoid
What is prognosis of appendiceal carcinoma?
good prognosis; rarely malignant
What do you see on histology with carcinoid?
- nesting tumor pattern
- round nuclei
- speckled chromatin
- evenly spaced
What is a mucinous cystadnoma?
usually benign mucus filled cyst in appendix
looks like villous adenoma on histology
What is a complication of cystadenocarcinoma?
invades wall –> can get pesudomyxoma peritonei = mucus accumulates outside appendix and mixed wtih neoplastic cells
What type of cancer is anal cancer usually?
squamous
Where does anal cancer usually spread?
locally –> rectal sphincter, prostate, vagina
met –> iliac and inguinal lymph nodes
