Abstract
A 65-year-old woman was referred to our hospital because of an intractable sigmoid colon ulcer. She had undergone a right nephrectomy for kidney stones, at age 33, and a uterectomy at age 39, followed by radiation therapy. Lower abdominal pain and hematochezia developed suddenly, following a few days of constipation, in September 1999, when she was admitted to the previous hospital because of left hydronephrosis. A punched-out oval ulcer was found in the sigmoid colon, on colonoscopic examination. She was treated with total parenteral nutrition, prednisolone, and mesalazine administration. Although her hematochezia and abdominal pain disappeared, diarrhea and abdominal pain occurred after she began eating, and she was referred to our hospital for further examination. Although intestinal lavage solution was used for bowel preparation, stercoromas were found in the rectum, which had to be manually removed before colonoscopic examination, and a stercoral-ulcer was suspected. The sigmoid colonic ulcer was intractable. A biopsy specimen, taken from the bottom of the ulcer, revealed bizarre interstitial cells, each with a large oval nucleus, showing the so-called "owl-eye-appearance." Although the diagnosis of radiation sigmoiditis is sometimes difficult, "owl-eye-appearance" is a useful pathological finding in the diagnosis of late-phase radiation-induced colitis.
