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A sessile serrated lesion (SSL) is a premalignant flat (or sessile) lesion of the colon, predominantly seen in the cecum and ascending colon. SSLs are thought to lead to colorectal cancer through the (alternate) serrated pathway. [1] [2] This differs from most colorectal cancer, which arises from mutations starting with inactivation of the APC ...
Traditional serrated adenoma seen under microscopy with H&E stain, showing serrated crypts. SPS may occur with one of two phenotypes: distal or proximal. [6] The distal phenotype may demonstrate numerous small polyps in the distal colon and rectum, whereas the proximal phenotype may be characterized by relatively fewer, but larger polyps in the proximal colon (cecum, ascending colon, etc.). [6]
Adenomatous polyp colon with malignant focus at apex. A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. [1] Untreated colorectal polyps can develop into colorectal cancer. [2] Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) or cause (e.g. as a consequence of ...
Sessile polyps larger than 2 cm usually contain villous features, have a higher malignant potential, and tend to recur following colonoscopic polypectomy. [18] Although polyps do not carry significant risk of colon cancer, tubular adenomatous polyps may become cancerous when they grow larger.
These adenomas may become malignant . Villous adenomas have been demonstrated to contain malignant portions in about 15–25% of cases, approaching 40% in those over 4 cm in diameter. [7] Colonic resection may be required for large lesions. These can also lead to secretory diarrhea with large volume liquid stools with few formed elements.
The pathophysiology of precancerous lesions is thought to be similar to that of cancer, and also varies depending on the disease site and type of lesion. [12] It is thought that cancer is always preceded by a clinically silent premalignant phase during which many oncogenic genetic and epigenetic alterations accumulate before it is truly malignant.
Adenomatous polyps may be classified based on morphology in order to identify lesions at increased risk of malignant transformation. For example, adenomatous polyps in the colon may be pedunculated (lobular head with a long slender stalk) or sessile (broad base).
Colonic polypectomy is the removal of colorectal polyps in order to prevent them from turning cancerous.. Method of removing a polyp with a snare. Gastrointestinal polyps can be removed endoscopically through colonoscopy or esophagogastroduodenoscopy, or surgically if the polyp is too large to be removed endoscopically.