Abnormal colonic wall thickening on computed tomography

There are many disease processes, both inflammatory and neoplastic, which can alter the colonic bowel wall. A retrospective study was done on surgically proven cases of colonic disease in which colonic bowel wall abnormalities were identified by computed tomography. Colonic bowel wall thickening was the most common finding, but was nonspecific. Finger-like projections extending from the bowel wall into the surrounding mesentery did help distinguish inflammatory change from neoplastic change. Examples of diverticulitis, appendicitis, Crohn's disease, carcinoma, lymphoma, and metastatic disease are presented.

Colonoscopy: an essential monitoring technique after resection of colorectal cancer

A pilot study was undertaken to determine the usefulness of colonoscopy in the postoperative follow-up of patients with colorectal cancer. Of 56 patients, 9 (17 percent) had positive intraluminal examinations, including one recurrent cancer and three large polyps (greater than 1 cm) despite normal barium enema films. Twenty percent had negative colonoscopic findings which ruled out suspicious lesions on roentgenograms. More than one third had alterations in therapy as a result of colonoscopic examination. Colonoscopy is a useful and fruitful diagnostic aid in the follow-up of colon cancer. It should be used early in the postoperative period and added at rational intervals in long-term surveillance. It appears to complement other accepted methods of detecting recurrence.

The colitides

Diverse signs may be seen on barium enema in the various forms of colitis. Barium enema is only reasonably specific in the diagnosis of Crohn's disease and ulcerative colitis once the other possible diseases have been excluded from consideration by biopsy, microscopy, culture, or therapeutic trial. In particular, campylobacter colitis has proved to be such a common entity that many patients originally thought to have had one attack of ulcerative colitis, ischemic colitis, or Crohn's colitis may never have had these diseases. Many of the relatively specific signs can be seen in a variety of conditions. For example, aphthae in the colon may be seen in Crohn's disease, yersinia enterocolitis, Behçet's syndrome, amebiasis, ischemia, tuberculosis, and campylobacter colitis. Continuity of disease is characteristic in ulcerative colitis. Nevertheless, patches of healing may occur, so that a rare patient may be seen during a resolving attack of ulcerative colitis in whom only scattered patches of active disease can be seen on barium enema. In general, few radiologic signs on barium enema are truly specific for one disease, with penumatosis cystoides coli being an exception to this rule. However, the sensitivity of barium enema with currently available materials for double-contrast techniques is such that radiology continues to be useful at present in diagnosing the colitides and in managing patients.

Postinflammatory polyposis (PIP) of the colon: the radiologic-pathologic spectrum

The radiologic-pathologic spectrum of postinflammatory polyposis (PIP) of the colon and the evolution of the radiographic appearance of PIP over time were retrospectively studied in 27 patients (21 with ulcerative colitis, 6 with Crohn disease). Two general patterns of radiographic evolution were recognized: progression from active, ulcerating disease to mucosal healing with formation of PIP, and interruption of healing with PIP by recrudescence of active ulceration with inflammatory pseudopolyposis. In these latter cases, disease activity recurred in the same areas in which healing with PIP had been recognized. A review of all pathologic material indicated that the histopathology of PIP is varied and depends, to a large extent, on polyp size.

Radiologic approach to the detection of colorectal neoplasia

Patients with early colorectal carcinoma detected by screening have a high survival rate. Most colorectal carcinomas evolve in preexisting adenomatous polyps, and the incidence of this malignant disease can be reduced by endoscopic polypectomy. Radiologic examination usually cannot differentiate between a benign polyp and a small carcinoma, which heightens the importance of their colonoscopic removal and subsequent histologic examination. The double-contrast enema has a higher degree of sensitivity for the detection of polyps, and probably also for early carcinoma, than the single-contrast enema. Because many of these lesions are asymptomatic, the double-contrast enema should be the standard radiologic examination of the colon in adults. This view has been championed by others and the technique has become more widely adopted. Its use contributes to the effort to reduce mortality from colorectal carcinoma.

Localized giant pseudo-polyposis in ulcerative colitis

Localized giant pseudo-polyposis is a rare complication of ulcerative or granulomatous colitis. A case illustrating the typical radiological findings is described. Recognition of this condition is important since it may simulate malignancy.

Colonoscopic diagnosis of inflammatory bowel disease

The indications and limitations of colonoscopy in the diagnosis of inflammatory bowel disease are well defined. The endoscopic examination is usually easily performed and well tolerated by the patient, but, since endoscopic examination of the colon is an invasive procedure (and potentially dangerous), colonoscopy should only be performed in those patients in whom the indication is clear and the benefits identifiable. Colonoscopy may provide valuable information in the diagnosis and may help outline the course of therapy in patients with inflammatory bowel disease.

Endoscopic removal of an intussuscepted appendix mimicking a polyp--an endoscopic hazard

A 55-yr-old white woman with a polypoid filling defect in the caput cecum, on barium enema examination, had endoscopic removal of this mass. This was immediately recognized macroscopically to be an intussuscepted appendix. This case is only the second naturally inverting appendix to be removed endoscopically, and it was complicated 18 h later by local peritonitis which was heralded by acute right lower quadrant pain. Laparotomy revealed a cleanly transected base of appendix and cecal adhesions representing previous chronic inflammatory disease. Endoscopists should consider this diagnosis in all cases of mass lesions of the caput cecum. It is imperative to retrieve such lesions if polypectomy is performed, as the macroscopic diagnosis is then evident. Once the diagnosis is established, immediate surgery is advised rather than watchful waiting.

Double-contrast barium-enema examination and endoscopy in the detection of polypoid lesions in the cecum and ascending colon

Fifty-three patients with 54 polypoid lesions in the ascending colon and cecum underwent colonoscopy and double-contrast barium-enema examination (DC-BE). Colonoscopy could not completely examine the cecum in three patients (failure rate 6%) and DC-BE had four false positive results. Colonoscopy detected 40 lesions (sensitivity 78%) and DC-BE 45 lesions (sensitivity 88%). A carcinoma and a villous adenoma were missed by both methods. The overall accuracy for colonoscopy was 80%, 76% if corrected for unsuccessful procedures; DC-BE showed accuracy rates of 82% and 83%. In combination, the two methods had 97% accuracy. This study shows that DC-BE is slightly better than colonoscopy for evaluating well-prepared patients with suspected polypoid lesions in the right colon, but stresses the complementary nature of the two methods and the need for repeating negative examinations by one modality in the presence of a positive result by the other.

The radiographic features of small colon cancers

The commonly accepted criteria for colon malignancy were investigated in malignant and benign polyps smaller than 3 cm in diameter. It was found that most small tumors, both benign and malignant, were sessile and smooth in outline. It was only when the polyps increased in size that their outlines became lobulated or irregular. A stalk was not seen in polyps smaller than 1 cm in diameter. Retraction at the base of a cancer was likewise not seen in these small lesions. The typical malignant characteristics became apparent only when the polyp had grown to 2 to 3 cm in diameter.

[The "false-positive polyp" during contrast examination of the colon (author's transl)]

44 cases of false-positive radiological diagnosis of colonic polyps are reviewed with regard to cause, frequency, distribution and radiological criteria. Most common causes are scybala and air bubbles (77%) and effects of overlapping and projection (19%). Due to extensive folding of the colon misinterpretations are frequently seen in the sigmoid and in the area of both flexures; the folding allows overlapping of mucosal structures and trapping of bowel contents. The validity of roentgen signs in polyp diagnosis and the limits of colonoscopy are discussed. Diagnostic reliability may be improved by optimal technique of examination and standardized proceeding.

[The radiological and clinical features of Gardner's syndrome (author's transl)]

Gardner's syndrome, completely expressed, consists of a trio of familial polyposis of the colon, osteomas and mesenchymal tumours of the skin. Inheritence is autosomal dominant. In many patients with familial polyposis of the colon, only mesenchymal skin tumours or osteomas can be demonstrated. It is therefore possible that Gardner's syndrome and familial polyposis represent two extremities of a single disease which is characterised by marked variability in the expressivity of the gene. Gardner's syndrome has been considered a rare condition occurring in only about 8% of patients with familial polyposis. Amongst the 20 patients with colonic polyposis from eleven families, mesenchymal and/or osseous lesions were found in seventeen (85%). Osteomas of the mandible were shown particularly frequently by orthopantomography. Since polyposis of the colon tends to remain symptomless for many years, the finding of osteomas in the facial skeleton, or recurrent skin tumours in young patients, should lead to further investigation.

The double contrast barium enema: why bother?

Despite a wealth of publications extolling the virtues of the double contrast barium enema (DCBE), it is clear that change is only gradual and that in many institutions the single contrast, full column barium enema (BE) is still the routine method of colonic investigation. Much of this may be due to a persistent belief, among the unconverted, that what was good enough yesterday is good enough today. There may also be a belief that an old dog cannot learn new tricks. At least, in many cases, he appears unwilling to try. These beliefs are all too often encouraged by a trickle of articles in the world literature that set out to refute the value of DCBE and thereby add fuel to the dying embers of "conservational" radiology. This article is an attempt to explode some of the persistent fantasies regarding DCBE by reviewing the literature, examining misconceptions, and, hopefully, laying them to rest in their graves--the position that overwhelming worldwide evidence as well as our own experience has assigned for them. I believe that there is little evidence to justify continued use of the barium enema as the standard technic for examining the colon.