Pathology of Neoplastic & Non-Neoplastic Polyps and Colon Cancer Flashcards
What is the most common side of colonic adenocarcinoma metastasis?
Liver - lymph nodes, bones, and lungs, are also common sites
What are the most common locations of carcinoid tumors?
Small intestine, appendix
Levels of this marker can be monitored to evaluate the management of adenocarcinomas.
CEA
Where are sessile serrated adenomas most commonly located?
Right colon
What are the general characteristics of cancers of the right colon?
Cauliflower-like masses, occult blood in stool
True/False. Familial adenomatous polyposis is a benign disorder that does not increase the risk of other cancers.
False - by age 40, nearly polyps become invasive adenocarcinoma.
What gene is mutated in familial adenomatous polyposis and its function?
APC gene - regulates beta-catenin in the Wnt pathway
What is the most important factor in determining the prognosis of a colonic adenoma?
Size - greater than 4cm is very likely to be cancerous.
These non-neoplastic colonic lesions are usually less than 5cm, most common in the left colon, and have a serrated appearance of goblet cells.
Hyperplastic Polyps
What is the most common cancer of the appendix?
Appendiceal carcinoid
A patient presents with the accompanying dermatological complaint. What is the name diagnosis and cause?
Mucocutanoues hyperpigmentation associated with Peutz-Jeghers Syndrome
Mutations of these genes are associated with colonic adenomas.
p53, SMAD4, APC
What is Turcot syndrome?
A rare variant of FAP that includes CNS tumors (gilomas)
This disease is autosomal dominant, most common in children <5yo, and has a cystic dilation appearance on histology.
Juvenile Polyposis
Carcinoid syndrome is a complication of carcinoid tumors. What is the pathophysiology and accompanying symptoms?
Occurs due to elaboration of serotonin due to carcinoids metastatic in the liver. Symptoms include flushing, diarrhea, right endocardial fibrosis, and bronchoconstriction
True/False. Villous lesions are more likely to cause cancer.
True - they can more easily penetrate the submucosa and muscularis propria than pedunculated lesions
Inflammatory polyps are non-malignant and due to chronic cycles of inflammation. What is the clinical triad of presentation?
Rectal bleeding, mucus discharge, inflammatory lesions on rectal wall
This disorder is a variant of FAP that also includes osteomas and abnormal dentition.
Gardner syndrome
What is the most common malignancy of the GI tract?
Colonic adenocarcinoma
What is the most common cause of pseudomyxoma peritonei?
Appendiceal mucinous cystadenocarcinoma
True/False. Grading is the most important prognostic factor for colonic adenocarcinoma.
False - staging is always more important in prognosis than grading.
What characteristics are considered in cancer staging?
Invasion of the lamina propria, lymph node involvement, metastasis
What are the two types of adenomatous polyps?
Pedunculated tubular and sessile villous
Polyps associated with Lynch Syndrome are most common where in the colon?
Right colon - ascending and transverse
This autosomal dominant juvenile disorder is characterized by mucocutaneous pigmentation, polyps with an arborizing network and increased risk of intussusception and other cancer.
Peutz-Jeghers Syndrome
What are the general characteristics of cancers of the left colon?
“Napkin-ring” configuration, “apple core” lesion, changes in bowel habits
What is the histological appearance of carcinoid tumors?
Nesting and trabecular pattern of small uniform cells
This disorder is caused by mutations of the MSH2 and MLH1 genes, responsible for DNA mismatch repair.
Lynch Syndrome - due to microsatellite instability
What two genetic pathways may lead to colonic adenocarcinoma?
Mutations of the APC gene (B-catenin pathway), mutations of DNA mismatch repair (microsatellite instability)
