Form-Vessel Classification of Cholangioscopy Findings to Diagnose Biliary Tract Carcinoma’s Superficial Spread

Abstract

We aimed to evaluate a newly developed peroral cholangioscopy (POCS) classification system by comparing classified lesions with histological and genetic findings. We analyzed 30 biopsied specimens from 11 patients with biliary tract cancer (BTC) who underwent POCS. An original classification of POCS findings was made based on the biliary surface’s form (F factor, 4 grades) and vessel structure (V-factor, 3 grades). Findings were then compared with those of corresponding biopsy specimens analyzed histologically and by next-generation sequencing to identify somatic mutations. In addition, the histology of postoperative surgical stumps and preoperative POCS findings were compared. Histological malignancy rate in biopsied specimens increased with increasing F- and V-factor scores (F1, 0%; F1, 25%; F3, 50%; F4, 62.5%; p = 0.0015; V1, 0%; V2, 20%; V3, 70%; p < 0.001). Furthermore, we observed a statistically significant increase of the mutant allele frequency of mutated genes with increasing F- and V-factor scores (F factor, p = 0.0050; V-factor, p < 0.001). All surgical stumps were accurately diagnosed using POCS findings. The F–V classification of POCS findings is both histologically and genetically valid and will contribute to the methods of diagnosing the superficial spread of BTC tumors.

Automatic detection of tumor vessels in indeterminate biliary strictures in digital single-operator cholangioscopy

“…In fact, the interobserver agreement for detection of TVs was reported to be only fair (κ = 0.26) in a recent retrospective cohort study 5 . Poor specificity of macroscopic features and reproducibility between different observers, as well as the retrospective nature of studies, have limited development of a widely accepted D-SOC classification system for indeterminate BS 6 13 14 .…”

Automatic Identification of Papillary Projections in Indeterminate Biliary Strictures Using Digital Single-Operator Cholangioscopy

“…Several features have been associated with malignant bile strictures, including masses, tumor vessels, ulcerated lesions, and PP (5). Nevertheless, no macroscopic classification system for macroscopic classification of biliary strictures has been widely accepted, and significant interobserver variability exists in the description of these lesions (5,8). PP have been shown to correlate with the presence of malignancy (5,8,9).…”

Choledochoscopy: An update

“…In a study by Pereira et al [ 74 ] involving 43 patients, the accuracy of DSOC-guided visual impression and DSOC-guided biopsy was 95% and 81% respectively in the diagnosis of CCA. To further increase diagnostic accuracy in identifying the superficial spread of CCA based on visual impression, Fukasawa et al [ 75 ] proposed the novel Form-Vessel Classification (F-V scores), stratifying the form of biliary surface and vessel structure seen on peroral choledochoscopy into four and three grades, respectively. Amongst the 30 biopsy samples from 11 patients, higher F-V scores corresponded with a higher histological malignancy rate and frequency of mutant alleles[ 75 ].…”