Preoperative evaluation of early colorectal cancer using an ultrasound mini probe

We investigated whether endoscopic ultrasonography (EUS) can assess the depth of invasion of early colorectal cancer exhibiting the V pit pattern on magnifying endoscopy with submucosal invasion of 1,000 μm or deeper.

Among 38 colorectal tumors exhibiting the V pit pattern on magnifying endoscopy, the findings on EUS with a mini-probe (15 MHz) were compared with histopathological findings. The diagnostic accuracy, sensitivity and specificity of EUS were examined separately in tumors exhibiting the Vi or V5 pit pattern.

Diagnostic accuracy of EUS for cancers exhibiting the Vi pit pattern on magnifying endoscopy with submucosal invasion of 1,000 μm or deeper was 9/15 (60%). Sensitivity was 90%, specificity 14.3%, positive predictive value 31.7% and negative predictive value 76.3%. Diagnostic accuracy of EUS for cancers exhibiting the VN pit pattern on magnify-ing endoscopy with submucosal invasion of 1,000 μm or deeper was 13/18 (72%). The sensitivity and specificity of EUS were 100% and 37.5%, respectively.

EUS tended to diagnose the invasion depth of cancer with submucosal invasion exhibiting the V pit pattern as deeper than it actually was. EUS accurately diagnosed early colorectal cancer with shallow invasion exhibiting the VN pit pattern and surgery was avoided.