Unusual case of late post-irradiation damage to the ileum.

Abstract

Radiation damage to the ileum, first mentioned by Walsh (21) in 1897, is of two types: acute, usually observed during the course of irradiation or just following it, and late, generally developing six months to five years after therapy. Occasional cases are seen much later than five years, when they present diagnostic problems because of obscure bleeding, partial small-bowel obstruction, or vague symptoms suggesting psychoneurosis as a predominant feature. Sometimes recurrent neoplasm has been mistakenly diagnosed. Perforation of the ileum has been an occasional complication. The primary disease for which radiation was given in such cases was most often carcinoma of the cervix uteri, though testicular tumors (2, 5) (treated for involvement of retroperitoneal nodes or prophylaxis of this area), carcinoma of the corpus uteri (15, 16, 20, 24), carcinoma of the colon (10), carcinoma of the ovary (14, 20), and plasma-cell myeloma of the ileum (18) are also among the initial conditions. It might be anticipated that irradiation for other intra-abdominal and retroperitoneal tumors could be implicated occasionally. While supervoltage has sometimes been responsible (2), most reported cases were treated in the orthovoltage range. Brick (5) estimated the injury threshold for the small bowel at 1,000 kv as 4,000 to 4,500 r. Peterson and Clausen (13) estimated that, with orthovoltage, acute mucosal damage may occur with 2,500 r, while 5,500 r to the retroperitoneal area will cause late radiation injury to the small intestine in about half the cases. Radiologic Findings The roentgenographic diagnosis of radiation damage to the ileum has been unsatisfactory. Stricture or ulcer has rarely been demonstrated. Part of this failure is due undoubtedly to insufficient examination of the small-bowel pattern. With better attention to this phase of gastrointestinal diagnosis, improvement should be possible. In the case to be presented here a capable radiologist reported a gastrointestinal series “normal” six months before operation, although in the immediate preoperative period the same examiner recognized a small bowel abnormality. This is by no means an unusual sequence. Although the possibility of radiation damage was considered preoperatively, because of the unusual time interval it was not given as a definite diagnosis. Pathology Warren and Friedman (22), in their comprehensive study of the pathology of small intestinal damage following irradiation, present as primary diagnostic criteria hyalinization of the connective tissue, abnormal fibroblasts, telangiectasia, and hyaline degeneration of the vessel walls. Secondary criteria are epithelial abnormalities, phlebosclerosis, and changes in the muscle fibers. In greater detail, these writers state that the connective tissue showed some degree of edema, and in the early phase this was dominant.