Usefulness of confocal laser endomicroscopy to diagnose ulcerative colitis-associated neoplasia

Chromoendoscopy, narrow-band imaging (NBI), and confocal laser endomicroscopy (CLE) have been introduced in ulcerative colitis (UC)-associated neoplasia surveillance. We aimed to determine the ability of CLE to differentiate among UC-associated neoplasia (differentiated type or undifferentiated type), sporadic adenoma, and circumscribed regenerative lesions. Of 665 patients with UC, we carried out probe-based CLE (pCLE) on 12 patients with suspected UC-associated neoplasia in addition to magnifying chromoendoscopy with crystal violet and NBI. We compared pCLE findings with pathological diagnoses. pCLE could differentiate UC-associated differentiated cancer from other pathologies such as solitary adenoma and non-neoplastic circumscribed regenerative lesions on the basis of back-to-back orientation of crypts (P = 0.048), and UC-associated undifferentiated cancer from other pathologies on the basis of dark trabecular architecture (P = 0.015). Sensitivity, specificity, and accuracy of combination of back-to-back orientation of crypts and dark trabecular architecture for carcinoma or dysplasia were 100%, 83%, and 92%, respectively. In vivo microscopic observation with pCLE was helpful to evaluate the suspected UC-associated neoplasia.