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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 ...
The risks of progression to colorectal cancer increase if the polyp is larger than 1 cm and contains a higher percentage of villous component. Also, the shape of the polyps is related to the risk of progression into carcinoma. Polyps that are pedunculated (with a stalk) are usually less dangerous than sessile polyps (flat polyps). Sessile ...
The types of polyps found in SPS include sessile serrated adenomas/polyps, traditional serrated adenomas, and hyperplastic polyps. SPS occurs in two phenotypes: proximal and distal. Proximal SPS has a greater risk of CRC than distal SPS. The vast majority of cases may be managed with colonoscopy with removal polyps (polypectomy). Polyp removal ...
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.
Cancers are caused by a series of mutations. Each mutation alters the behavior of the cell somewhat. Cancer is fundamentally a disease of tissue growth regulation. For a normal cell to transform into a cancer cell, the genes that regulate cell growth and differentiation must be altered. [98] The affected genes are divided into two broad categories.
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 ...
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 countless polyps in the colon predispose to the development of colon cancer; if the colon is not removed, the chance of colon cancer is considered to be very significant. Polyps may also grow in the stomach, duodenum, spleen, kidneys, liver, mesentery, and small bowel. In a small number of cases, polyps have also appeared in the cerebellum.