Identification of volumetric laser endomicroscopy features of colon polyps with histologic correlation

There are limited data on the use of volumetric laser endomicroscopy (VLE) for imaging colon polyps. Our aim was to identify VLE features of colon polyps.

A total of 45 patients were included; 43 underwent endoscopic mucosal resection of colorectal polyps 2 cm or greater. These polyps were then scanned with VLE immediately after resection. Two patients who underwent partial colonic resection served as controls.

Forty-three polyps were included with review of matching histology: 3 intramucosal cancer (IMCA), 5 tubular adenoma (TAs)/tubulovillous adenoma (TVA) with high-grade dysplasia (HGD), 9 TVA with only low-grade dysplasia (LGD), 5 serrated adenoma, and 21 TA with LGD. All TAs and TVAs were hyper-reflective compared with normal tissue. Effacement occurred in 82.4% (14/17) of the colonic polyps with advanced pathology (TVA with HGD/IMCA) compared with 11.6% (3/26) with non-advanced pathology (TA with LGD and serrated adenoma) (P < .0001). Forty-seven percent (8/17) of polyps with advanced pathology had greater than 5 glands on VLE compared with none in the non-advanced pathology group (P = .0001). An irregular surface mainly occurred in polyps with high-grade pathology (HGD/IMCA) versus TAs. Eighty-eight percent of polyps with HGD/IMC had an irregular surface (7/8) versus 6% (2/35) of TAs (P < .0001).

In this ex vivo clinicopathologic study, we show that there are distinct VLE features of colon polyps that may help identify polyps or features of a higher-grade lesion. This may have implications for possible in vivo application to aid in dysplasia or polyp detection.