Polyps are an abnormal growth of cells originating from mucous membranes in the body. The fleshy cylindrical or spherical growths can be found anywhere there are mucous membranes including the colon, bladder and cervix. A malignant polyp starts as a small, benign fleshy tumor, but becomes a cancerous growth over time. Colon cancer, one of the leading forms of cancer, develops from malignant polyps located on the inner lining of the large intestine. Although the exact cause of malignant polyp formation is unclear, factors that may influence their development include heredity, diet and the size of the polyp.
A number of different polyps form from mucous membranes in the body, with varying risks of becoming cancerous. Nasal polyps are found in the nose and sinuses and are benign. Endometrial polyps occur in the uterus and rarely become malignant if formed before menopause. The risk for malignant polyp growth in the uterus increases during and after menopause. A very small percentage of cervical polyps become cancerous, while large polyps in the bladder may become malignant.
A polyp extends from the mucous membranes lining the organs of the body and takes a mushroom-like shape with a stem or a flatter, button-like shape with a broad base. Although commonly found and frequently benign, most polyps removed from the body undergo a biopsy to determine if they contain cancerous cells. Colon cancer is one of the most common cancer types and develops from specific malignant polyp growths called adenomatous polyps. These polyps, also known as adenomas, are the most common kind that develop in the colon. Only a small percentage of adenomas will become malignant.
Factors that influence the formation of a malignant polyp include diet and nutrient intake. Colon cancer studies have found that a high-fat, low-fiber diet may increase malignant polyp growth. Low dietary calcium may also increase risk for cancerous polyp formation. Other factors that can add to this risk include increasing age, smoking and heredity. In addition, the larger the polyp the more likely it is to become cancerous.
Researchers have found that a sedentary lifestyle may also contribute to cancerous polyp formation. An increased risk for malignant colon polyps is found in patients with long-term inflammatory colon diseases. Obesity has also been linked to an increased risk of developing certain cancers, including colon cancer.
Malignant polyp growth may have no noticeable symptoms, and patients may be unaware of a polyp until it is found during an examination. Some symptoms that may indicate polyp growth include bleeding, changes in bowel habit or painful or frequent urination. Treatment generally begins with the removal and examination of the polyp to determine if it is cancerous. The health care provider establishes a plan for any further treatment based on the results of the biopsy.
