Photo Rounds

Rectal bleeding

A 72-year-old man presented to his family physician (FP) with complaints of rectal bleeding and changes in his bowel movements that had begun several months earlier. He had a history of hemorrhoids, but was not experiencing rectal irritation or itching. The patient’s stool sample tested positive for blood, but anoscopy failed to identify the source of the bleeding. On colonoscopy, a mass was seen in the cecum.

What's your diagnosis?


A biopsy was obtained and pathology confirmed adenocarcinoma, the most common type of colon cancer. Colon cancer is the third most common cancer in both men and women in the United States, second only to lung cancer as a cause of death.

The diagnosis of colon cancer is sometimes made following a positive screening test (eg, digital rectal examination, fecal occult blood test, sigmoidoscopy, colonoscopy, or barium enema). For patients who have signs and symptoms suggestive of colon cancer, the confirmative diagnostic test most commonly performed is colonoscopy with biopsy.

Colonoscopy allows direct visualization of the lesion, examination of the entire large bowel for synchronous and metachronous lesions, and collection of tissue for histologic diagnosis.

In this case, the patient underwent a partial colectomy. Examination of the liver, pelvis, hemidiaphragm, and full length of the colon during surgery showed no metastases. Despite the large size of the primary tumor, pathology indicated that it was confined to the bowel wall with invasion into the muscularis propia (Duke B). Other tests and computed tomography imaging showed no evidence of metastases or lymph node involvement.

The patient decided not to take the adjuvant chemotherapy and recovered from his surgery. He agreed to have screening colonoscopy on a frequent and regular basis along with monitoring of his blood for post-treatment carcinoembryonic antigen levels.

Photo Courtesy of Marvin Derezin, MD. Text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Smith M, Wang B. Colon cancer. In: Usatine R, Smith M, Mayeaux EJ, et al. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:399-404.

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