Tubular adenoma vs Villous or tubulovillous adenoma
How to tell Tubular adenoma and Villous or tubulovillous adenoma apart when a board question makes them look alike.
Tubular is usually pedunculated and lower risk; villous/tubulovillous is sessile, larger, and higher cancer risk.
Side by side
Common pedunculated adenomatous colon polyp with dysplasia and lower malignant risk than villous architecture when small.
Sessile villous or mixed tubulovillous adenoma, often larger and distal, with higher malignant potential and sometimes secretory diarrhea.
Adenomatous dysplasia grows in tubular glands and can progress through adenoma-carcinoma sequence as mutations accumulate.
Greater villous architecture and broad sessile growth correlate with higher dysplastic surface area and cancer risk.
Small pedunculated tubular adenoma with low-grade dysplasia supports lower-risk adenomatous polyp.
Large sessile villous lesion, high-grade dysplasia, size over two centimeters, or mucinous secretory symptoms support higher-risk adenoma.
The trap
All adenomas are premalignant, but villous architecture, size, and sessile shape raise the danger.
The repair move
For adenoma questions, rank risk by size, villous architecture, dysplasia grade, and sessile growth.
Try a free question
CoreA colonoscopy finds a small pedunculated adenomatous polyp composed mostly of tubular glands with low-grade dysplasia. Which polyp type best fits?
Show answer and explanation
Answer: A. Tubular adenoma. Pedunculated adenomatous polyp with tubular glands fits tubular adenoma.
Why the other choices are tempting
- B. Villous adenoma is more often broad, sessile, and higher risk.
- C. Hyperplastic polyp is not an adenomatous dysplastic lesion.
- D. Inflammatory pseudopolyps arise in inflammatory bowel disease and are not true adenomas.
- E. Hamartomatous polyps show disorganized benign tissue rather than adenomatous dysplasia.
Flashcards
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Which adenoma architecture has lower malignant risk?
Tubular architecture generally has lower malignant risk than villous architecture, especially when small.
Which adenoma architecture has higher malignant risk?
Villous or tubulovillous architecture has higher malignant potential.
Quick answers
What is the fastest way to tell Tubular adenoma from Villous or tubulovillous adenoma?
Tubular is usually pedunculated and lower risk; villous/tubulovillous is sessile, larger, and higher cancer risk.
What is the key clue for Tubular adenoma?
Common pedunculated adenomatous colon polyp with dysplasia and lower malignant risk than villous architecture when small.
What is the key clue for Villous or tubulovillous adenoma?
Sessile villous or mixed tubulovillous adenoma, often larger and distal, with higher malignant potential and sometimes secretory diarrhea.
What is the common trap with Tubular adenoma vs Villous or tubulovillous adenoma?
All adenomas are premalignant, but villous architecture, size, and sessile shape raise the danger.