Polyps are protrusions of the colon that occur in various types and stages. Most of them are sporadic, though occasionally they are part of a syndrome. They can be flat, sessile, or pedunculated. A few polyps arise from the submucosa, though most arise from the mucosa. There are several types of polyps, including hyperplastic polyps and adenomatous polyps. Some polyps have a high potential for malignancy, while others are benign.
Nonneoplastic polyps
Nonneoplastic polyps in the colon are usually benign and rarely develop into cancer. The most common types are adenomas and hyperplastic polyps. Each one can vary in size and degree of dysplasia. The size of polyps should be measured by a doctor to determine their risk for cancer.
Nonneoplastic polyps typically do not grow very large. However, they can get larger over time. Most polyps are stable in size during the first three to ten years, although growth may occur in some patients. In a recent study, 50% of polyps that were 6-10 mm in size, experienced growth over this time. However, the study noted that there was no correlation between growth rate and malignancy.
Despite the importance of early detection, non-neoplastic polyps are not as common as some other types. Intestinal polyps are often benign and can occur in the distal colon. Their apical crypts are, usually lined with goblet cells or mucin droplets. Researchers are currently working to develop molecular methods to distinguish between neoplastic and non-neoplastic polyps.
Ultrasound and sonographic assessments are useful tools for assessing the morphology of polyps. However, most studies use surgical specimens to determine morphologic characteristics. In addition, these studies often include only patients who had cholecystectomy. Histologic analyses are also limited. As a result, many studies categorize polyps into malignant and benign polyps.
