Polyps, both malignant or benign, are cell clusters that grow on the body’s mucous membranes. The areas where they most often occur include the sinuses and nose and the stomach. The bladder and the uterus are also common locations; however, they are most common in the colon. It’s possible to find polyps in other mucosal areas, such as the small intestine or cervix, but this is less likely. A malignant or cancerous polyp often begins as benign and changes over time.
Colon polyps frequently occur with few or no symptoms until the disease has seriously progressed. For this reason, regular examinations that include colonoscopies are important for anyone over the age of 50. In addition to older adults, smokers, people who habitually consume alcohol, and those who eat a lot of fatty calories and little fiber have higher occurrences of polyps. Overweight individuals are at increased risk as are those of African-American or Ashkenazi Jewish descent. Anyone with a familial history of cancer, especially colon cancer, who also belongs to one of the aforementioned groups is at an increased risk and should be diligent about regular cancerous polyp screenings.
There are a number of types of polyps. The first distinction involves how the polyp is attached. Some grow from the mucosal surface via a thin stem; these are pedunculated polyps. Others appear directly on the surface without the connecting stem; these are sessile polyps. A large, sessile growth is considerably more likely to become a cancerous polyp than a small, pendunculated one.
Other distinctions among colon polyp types include adenomatous, inflammatory, and hyperplastic. Adenomatous polyps are the most common and make up more than 60% of all polyps. Most do not actually become cancerous; however, because nearly two thirds of all polyps fall into this category, statistically, most of those that are in fact cancerous are adenomatous.
Inflammatory polyps most often occur as a result of ulcerative colitis or in patients with Crohn’s disease. These two conditions do increase colon cancer risk; however, it should be noted that inflammatory polyps are the least cancerous. Nonetheless, anyone who has experienced bouts of irritable bowel syndrome, colitis, or other bowel disorders should have regular checkups. The great majority of the rest fall into the category of hyperplastic polyps. They are most likely to be found in the descending colon and the rectum. They are nearly always benign and remain so.
While a cancerous polyp frequently doesn’t cause symptoms, those in high risk groups should be familiar with symptoms that may occur. One symptom is bloody stools, which can contain red, bloody stripes or can be black in appearance and tarry. Rectal bleeding, another symptom, can manifest as a spot or streak of red blood on toilet paper; however, this is also a very common symptom of hemorrhoids or anal tears. Stools that are regularly thin and ribbon-like can indicate the presence of colon cancer. Although pain isn’t strongly associated with a cancerous polyp, a malignant mass that obstructs the bowel can result in nausea and sometimes vomiting and abdominal cramps.