Colorectal Polyps and Syndromic Associations

Question-and-answer flashcards covering the classification of colorectal polyps, their malignant potential, and key hereditary polyposis syndromes.

What distinguishes non-neoplastic from neoplastic colorectal polyps in terms of malignant potential?

Non-neoplastic polyps are generally benign with little to no cancer risk, whereas neoplastic (adenomatous) polyps contain dysplastic epithelium and are premalignant.

Which type of non-neoplastic polyp shows a small, serrated surface, is usually found in the left colon, and carries a very low cancer risk?

Hyperplastic polyp.

Colorectal polyps that arise from chronic inflammation, such as in inflammatory bowel disease, are called _ polyps.

Inflammatory polyps (pseudopolyps).

What is the typical malignant potential of hamartomatous polyps outside of a genetic syndrome?

Variable; it depends on the associated syndrome or context, but is generally low to moderate.

Which adenoma subtype is characterized by tube-like glands and carries a moderate risk of malignant transformation?

Tubular adenoma.

Finger-like projections on histology are characteristic of which adenomatous polyp, and what is its relative cancer risk?

Villous adenoma; it has a higher risk of malignancy than tubular adenomas.

Adenomas that display both tubular and villous architecture are called _ adenomas and have what level of cancer risk?

Tubulovillous adenomas; they carry an intermediate risk of malignancy.

Which serrated lesion is a precursor to colorectal carcinoma via the microsatellite instability (MSI) pathway and carries significant malignant potential?

Sessile serrated adenoma/polyp (SSA/P).

Name the hereditary syndrome characterized by hundreds to thousands of adenomatous polyps in the colon.

Familial Adenomatous Polyposis (FAP).

If left untreated, what is the approximate lifetime colorectal cancer risk in Familial Adenomatous Polyposis (FAP)?

Nearly 100%.

Which polyposis syndrome presents with hamartomatous GI polyps and distinctive mucocutaneous pigmentation?

Peutz-Jeghers Syndrome.

Peutz-Jeghers Syndrome increases the risk of which types of malignancy?

Gastrointestinal and extra-GI cancers (e.g., pancreatic, breast, ovarian).

Multiple juvenile (hamartomatous) polyps in the GI tract are characteristic of which syndrome, and what is its cancer risk?

Juvenile Polyposis Syndrome; it confers an increased risk of gastrointestinal cancer.

Which hereditary cancer syndrome typically shows few or no colon polyps but carries a very high colorectal cancer risk via the MSI pathway?

Lynch Syndrome (Hereditary Nonpolyposis Colorectal Cancer, HNPCC).

What molecular pathway is commonly implicated in both sessile serrated adenomas and Lynch Syndrome–related cancers?

Microsatellite instability (MSI) pathway.