Introduction
Primary sclerosing cholangitis (PSC) is known to present characteristic cholangiographic findings; however, detailed observations using peroral cholangioscopy (POCS) have rarely been reported. We previously reported that POCS findings in PSC can be classified into three types: active (inflammatory), chronic (scarring), and tumorous (tumor-like). These findings may aid in the differential diagnosis of PSC and may be useful in predicting prognosis.
Aims & Methods
We aimed to analyze POCS findings in PSC in detail based on this classification and to clarify their characteristics by evaluating the frequency of each finding, their temporal changes, and comparisons with other biliary diseases.
We retrospectively reviewed 22 patients with PSC who underwent POCS between February 2018 and February 2023. For comparison, we included 19 cases of hepatolithiasis, 25 cases of cholangiocarcinoma, and 3 cases of IgG4-related sclerosing cholangitis (IgG4-SC). Twelve POCS findings were categorized into three types: active (mucosal erythema, ulcers, fibrous white exudates, irregular surface), chronic (longitudinal scarring, annular scarring, pseudodiverticula, stenosis), and tumorous (dilated vessels, tortuous vessels, friability, mass formation). In addition, we included “punched-out lesion (POL)” as an original finding. Each finding was graded on a 5-point scale (0–4) based on the extent or number of lesions, and scores were calculated for each type. We conducted three analyses: (1) correlation between cholangiographic and POCS findings in PSC, (2) temporal changes in POCS findings in PSC, and (3) comparison of POCS findings between PSC and other biliary diseases.
Results
In the first analysis, annular scarring (100%), stenosis (89%), POL (89%), and longitudinal scarring (86%) were frequently observed in PSC. Annular scarring was identified in all cases with a shaggy appearance on cholangiography, and stenosis were present in all ducts with band-like stricture. In ducts showing diverticulum-like outpouchings, longitudinal and annular scarring, pseudodiverticula, and POL were consistently seen, whereas other findings were absent. In the second analysis, active and tumorous scores varied over time even within the same case, whereas chronic scores remained stable or showed a progressive increase. A negative correlation was observed between active and chronic scores (p-value <0.001, r =-0.702). In the third analysis, chronic findings and POL were significantly more common in PSC compared to other diseases (p-value <0.001). Pseudodiverticula were seen exclusively in PSC, while dilated and tortuous vessels and friability were significantly more frequent in cholangiocarcinoma and IgG4-SC (p-value <0.001).
Conclusion
These findings suggest that the characteristic cholangiographic findings of PSC are mainly formed by chronic scarring. Diverticulum-like outpouchings reflect only fibrotic changes. Furthermore, the coexistence of inflammation and fibrosis, along with the time-dependent progression of fibrosis, is a unique feature of PSC, although active inflammation may obscure chronic findings. Finally, longitudinal scarring and POL were particularly prominent in PSC, and pseudodiverticula were highly specific to this disease, suggesting their usefulness in differential diagnosis. In conclusion, chronic findings on POCS are characteristic of PSC and may serve as a helpful tool in its diagnosis and differentiation from other biliary diseases.
References
T Fujisawa, M Ushio, S Takahashi, et al., Role of Peroral Cholangioscopy in the Diagnosis of Primary Sclerosing Cholangitis. Diagnostics (Basel), 2020. 10(5).
T Itoi, T Kamisawa, Y Igarashi, et al., The role of peroral video cholangioscopy in patients with IgG4-related sclerosing cholangitis. J Gastroenterol, 2013. 48(4): p. 504-14.
T H Karlsen, T Folseraas, D Thorburn, et al., Primary sclerosing cholangitis - a comprehensive review. J Hepatol, 2017. 67(6): p. 1298-1323.
T Nakazawa, K Notohara, S Tazuma, et al., The 2016 diagnostic criteria for primary sclerosing cholangitis. J Gastroenterol, 2017. 52(7): p. 838-844.
T Nakazawa, H Ohara, H Sano, et al., Cholangiography can discriminate sclerosing cholangitis with autoimmune pancreatitis from primary sclerosing cholangitis. Gastrointest Endosc, 2004. 60(6): p. 937-44.
H Isayama, S Tazuma, N Kokudo, et al., Clinical guidelines for primary sclerosing cholangitis 2017. J Gastroenterol, 2018. 53(9): p. 1006-1034.
W L Campbell, M S Peterson, M P Federle, et al., Using CT and cholangiography to diagnose biliary tract carcinoma complicating primary sclerosing cholangitis. AJR Am J Roentgenol, 2001. 177(5): p. 1095-100.
