Carcinoma of the hepatic flexure with proximal lymphatic invasion mimicking Crohn's disease

A primary adenocarcinoma of the transverse colon mimicking Crohn's disease: a case report and literature review

Diarrhoea and weight loss are presenting features of both Crohn's disease and colorectal cancer; however, the two conditions can usually be distinguished on the basis of characteristic patterns of abnormalities observed at the time of initial blood testing and imaging. In patients with suspected Crohn's disease these are often considered sufficient grounds to commence empirical treatment before the results of histology are available. This case report describes a 45-year-old man whose initial clinical, endoscopic and radiological investigations were strongly suggestive of a diagnosis of Crohn's disease, but who subsequently was found to have an adenocarcinoma of the mid-transverse colon. He went on to have an emergency extended right hemi-colectomy.

Unusual causes of colonic wall thickening on computed tomography

Computed tomography (CT) appearances in "colitis" are often non-specific, and include mural thickening and mesenteric fat stranding. In the western world, the majority of cases will have, or be subsequently diagnosed with, inflammatory bowel disease, pseudomembranous colitis or ischaemic colitis. However, other rare conditions may also produce these rather non-specific signs. We present a number of cases demonstrating colonic wall thickening on CT due to rarer diagnoses, which are correlated with the histopathological features. Some of these CT appearances have not been described previously in the literature.

CT of patients with right-sided colon cancer and distal ileal thickening

OBJECTIVE

The purpose of this study was to analyze the incidence and primary causes of distal ileal wall thickening in 131 patients with right-sided colon cancer.

SUBJECTS AND METHODS

During a 2-year period, 131 patients underwent surgical resection for right-sided colon cancer. Of these patients, we analyzed 13 who had distal ileal wall thickening on CT before surgery and also had the cause determined at pathology. CT findings were analyzed with regard to the morphologic features of colonic tumors, bowel wall involvement patterns of the distal ileum, and changes in the pericolic space.

RESULTS

Distal ileal wall thickening occurred in 13 (10%) of the 131 patients who had right-sided colon cancer. Three patients had polypoid colon cancer, whereas the other 10 had infiltrative colon cancer. The mean thickness of the involved colonic segments was 1.6 cm (range, 1.0-2.2 cm) with a mean length of 5.2 cm (range, 2.5-10.0 cm). Pericolic infiltration was mild in six patients and moderate in four patients. The mean length and thickness of the affected ileal segments were 3.2 cm (range, 1.5-6.0 cm) and 1.1 cm (range, 0.7-2.0 cm), respectively. On histopathologic examination, neoplastic processes involved the distal ileum in nine (69%) of the 13 patients. This involvement was caused by either direct tumor invasion in seven patients or lymphatic spread in two. In four patients (31%), nonneoplastic processes with edema and congestion involved the distal ileum.

CONCLUSION

The distal ileum may be abnormally thickened in about 10% of patients with right-sided colon cancer; this thickening results from tumor extension (69%) or a nontumorous process (31%).