Background/aims: To analyze the utility of stereomicroscopic evaluation for the diagnosis of early colorectal cancer using pit patterns and sample targeting and localized biopsy and the relationship between subclassification of the type IIIL pit pattern and histopathology.
Methodology: A total of 196 colorectal neoplasms (including 110 colorectal neoplasms with type-IIIL pit pattern) were completely resected endoscopically and observed by stereomicroscopy from August 2005 to July 2007. The histopathological results of the suspicious parts with pit patterns associated with early colorectal cancer under stereomicroscopy were compared with conventional pathological examinations slicing the entire specimen at random. We divided neoplasms with a type-IIIL pit pattern into three subclasses (IIIL-A IIIL-B and IIIL-C), according to the morphologic and prominent stereomicroscopy findings. We examined the relation between these three subclasses and histology.
Results: The diagnosis rate of early colorectal cancer was 33.7% (66/196) by targeted and localized biopsy under stereomicroscopy, whereas it was only 6.1% (12/196) by conventional pathological examination (P<0.001). Subtype IIIL-C are significant predictors for early colorectal cancer.
Conclusions: Sample targeting and localized biopsy under stereomicroscopy and subclassification of the type IIIL pit pattern is useful for improving the diagnosis rate of early colorectal cancer.