49-year-old male displayed bloody stools. A pedunculated polyp was removed endoscopically by sling resection.
- A cross-section of the adenoma and its stalk is shown.
- The fibro-vascular stalk is lined by inconspicuous colonic mucosa with exclusive presence of goblet cells. An invasive carcinoma is not present.
- The adenomatous head protrudes fungus-like and displays abundant dyplastic epithelial glands with basophilic appearance.
- The adenoma is composed of tubular glands and villous projections. The latter correspond to the elongated leaf-like projections.
- The normal glandular architecture is lost. The tall columnar lining cells exhibit a loss of mucus and display elongated hyperchromatic nuclei. In a small part, stratification and loss of polarity are observed. Mitotic figures are present.
Definition: Tubulovillous adenomas display a villous architecture in 20%-80% of the adenoma.
Precursor lesions: Adenomas of the colon may evolve into carcinomas (adenoma-carcinoma-sequence) necessitating complete polypectomy. Histological evaluation of the stalk will allow determination of the completeness of the resection.