Performance of CT in the locoregional staging of colon cancer: detailed radiology-pathology correlation with special emphasis on tumor deposits, extramural venous invasion and T staging.

PURPOSE: To investigate the performance of computed tomography (CT) in the local staging of colon cancer in different segments, with emphasis on parameters that have been found to be significant for rectal cancer, namely, extramural venous invasion (EMVI) and tumor deposits (TDs). METHODS: CT and pathology data from 137 patients were independently reviewed by radiology and pathology teams. The performance of CT in categorizing a given patient into good, versus poor prognostic groups was assessed for each segment, as well as the presence of lymph nodes (LNs), TDs and EMVIs. Discordant cases were re-evaluated to determine potential sources of error. Elastic stain was applied for EMVI discordance. RESULTS: The T staging accuracy was 80.2%. For T stage stratification, CT performed slightly better in the left colon, and the lowest accuracy was in the transverse colon. Under-staging was more common (in 12.4%), and most of the mis-staged cases were in sigmoid colon. According to the first comprehensive correlative analysis, the sensitivity, specificity, and accuracy of CT for detecting TDs were found to be 57.9%, 92.4%, 87.6%, respectively. These figures were 44.7%, 72.7%, and 63.5% for LN, and 58.5%, 82.1% and 73% for EMVI. The detection rate was better for multifocal EMVI. The detection rate was also comparable (although substantially underestimated) for LNs, with the half of the LNs missed by CT being < 5 mm. Four patients that were classified as TD by CT, disclosed to be LNs by pathology. Correlative analysis led to refinement of the pathology criteria, with subsequent modifications of the initial reports in 13 (9.5%) patients. CONCLUSION: Overall, CT performed well in the evaluation of colon cancer, as did TD and EMVI. It is advisable to include these parameters in CT-based staging. Radiologists should be aware of the pitfalls that occur more commonly in different segments.

A case of seatbelt-induced mesenteric injury and delayed colon ischemia after a car accident.

Trauma is the sixth leading cause of death globally and the leading cause of morbidity and mortality in young patients. Blunt bowel and mesenteric injuries are rare, occuring in only 1-5% of blunt abdominal traumas, and are associated with high morbidity and mortality. In this report, we present a case of a patient with sigmoid colon perforation due to ischemia caused by mesenteric injury, who was admitted to the hospital with abdominal pain two days after a car accident. A twenty-one-year-old man was admitted to the emergency department with abdominal pain and vomiting, having been involved in a car accident as a driver two days prior. Computed tomogra-phy revealed free air in the abdomen, originating from the perforation of the sigmoid colon wall, and free fluid in the pelvic area. The patient underwent immediate laparotomy. Exploration revealed a rupture in the sigmoid mesocolon, causing ischemia and perforation. Additionally, there was a rupture in the mesentery of the terminal ileum close to the ileocecal valve, but without ischemia. Partial sig-moid colon and ileal resections were performed, followed by colocolic anastomosis and double-barrel ileostomy. He was discharged in good health after a 20-day hospital stay. Thorough clinical examination and radiological evaluation can aid in detecting visceral injuries in trauma patients. Early recognition and repair of intestinal damage can prevent severe complications.