Polyps, Colorectal

• • Colorectal polyps are masses of tissue that project into the lumen

  • Heterogeneous group of sessile or pedunculated; benign or malignant; mucosal, submucosal, or muscular lesions

  • Types include:

  • -Neoplastic (adenomas/carcinomas)

    -Hamartomas

    -Inflammatory

    -Hyperplastic

  • Most adenomas are tubular, tubulovillous, or villous

  • Hyperplastic polyps are diminutive lesions most often found in the left colon

  • Hamartomas are uncommon (rarely malignant)

  • Adenomas are a premalignant lesion

  • Vast majority of adenocarcinomas of the large bowel in North America and Europe are believed to evolve from adenomas

Epidemiology

• • Estimates of the incidence of colonic and rectal polyps in the general population range from 9% to 60%

  • Polypoid adenomas are found in about 25% of asymptomatic adults who undergo screening colonoscopy

  • Prevalence of adenomas is 30% at age 50 years, 40% at age 60, 50% at age 70, and 55% at age 80

  • Mean age is 55 years

  • 50% of polyps occur in the sigmoid or rectum

  • 50% of patients with adenoma have more than 1 lesion, and 15% have more than 2 lesions

  • Increased incidence of adenomas in breast cancer patients has been reported

  • Inflammatory polyps have no malignant potential

  • Cancer developing in association with hamartomas is rare

  • 25% of patients who have 5 or more adenomatous polyps have a synchronous colon cancer at the initial colonoscopy

Symptoms and Signs

• • Most polyps are asymptomatic but the larger the lesion, the more likely it is to cause symptoms

  • Rectal bleeding most common symptom

  • Blood is bright red or dark red depending on the location of the polyp

  • Bleeding is usually intermittent

  • Altered bowel habits (constipation, increased frequency)

  • Crampy abdominal pain

  • Physical exam yields little information about the colonic polyps themselves

  • Polyp may be palpable by digital rectal exam

Laboratory Findings

• • Anemia may be present with rectal bleeding

Imaging Findings

• •Barium enema: Rounded filling defect with smooth, sharply defined margins

  • Colonoscopy: Most reliable means of diagnosis with biopsy; treatment with polypectomy

• • Malignant neoplasm

  • Artifacts seen on barium enema (such as fecal matter, air bubbles, appendices epiploicae, lymph nodes) may be confused with polyps

  • Diverticula

Rule Out

• • Malignant neoplasm

• • History and physical exam

  • Digital rectal exam

  • Proctoscopy

  • Colonoscopy with biopsy/polypectomy

  • Barium enema

When to Admit

• • Bleeding or other complications such as perforation, severe abdominal pain, obstruction

• • Polyps of the colon and rectum are treated because they produce symptoms, because they may be malignant when first discovered, or because they may become malignant later

  • Small polyps can be removed with an electrocautery snare

Surgery