DIAGNOSTIC PERFORMANCE OF CRYSTAL VIOLET CHROMOENDOSCOPY – RESULTS FROM A GERMAN CENTER

Aims:

The precise characterization of colorectal neoplasms is necessary because it influences the choice of treatment. Kudo's pit pattern classification has shown excellent diagnostic performance. In Germany, data on the use of crystal violet (CV) solution to describe the surface pattern of colorectal lesions is lacking. In this study, we describe the diagnostic outcomes of CV-chromoendoscopy on colorectal neoplasms.

Methods:

A 0,05% CV solution was used to stain the surface of 62 colorectal polyps. The surface pattern of each polyp was described. Polyps were categorized into Kudo types I, II, IIIs, IIIL, IV, Vi and Vn. The pit pattern diagnosis was compared with the histology. Furthermore, a simplified pit pattern classification using one of three categories: regular surface, irregular surface and amorphous surface was used on the same polyps and also compared with histology.

Results:

4 sessile serrated adenomas (SSA), 21 low-grade intramucosal neoplasia (LGIEN), 31 high-grade intramucosal neoplasia (HGIEN), 1 low-risk submucosal invasive carcinoma and 5 deeply invasive carcinoma were stained with crystal violet. Type IIIs/IIIL and IV showed LGIEN/HGIEN in 100% and 96% respectively. Type Vi had a HGIEN histology in 89% while type Vn had a diagnostic accuracy of 86% for cancer. In the simplified pit pattern classification, a regular surface pattern showed LGIEN/HGIEN in 93%, an irregular surface showed HGIEN in 77% and an amorphous surface pattern had a diagnostic accuracy of 83% for cancer.

Conclusions:

With CV chromoendoscopy and Kudo's pit pattern, colorectal polyps can be classified correctly into adenomas and carcinomas with a high degree of accuracy. A simplified description of the surface pattern after CV staining also has a high degree of accuracy for the characterization of colorectal polyps.