Patients with cholestatic liver function tests and histological features of primary sclerosing cholangitis (PSC), but a normal cholangiogram are considered to have small duct PSC.
In this study, researchers from Europe identified 33 patients with small duct PSC from 2 centers (Oxford, England and Oslo, Norway).
A further group of 260 patients with large duct PSC was identified.
| Patients with small duct PSC have significantly better survival compared with large duct patients.|
The groups were compared, and their prognosis in terms of death, cholangiocarcinoma, biochemical features, histological features, and symptoms were analyzed.
The research team found that the mean age of patients at diagnosis was 38 years and 39 years, in small duct and large duct PSC, respectively.
In addition, mean follow up was 106 months in small duct and 105 months in large duct patients.
The team identified 4 patients, originally considered to have small duct PSC, who developed large duct PSC. Of these, 2 underwent liver transplantation during follow up.
Of the large duct patients, 47% either required liver transplantation or died.
The team found that small duct patients had a significantly better survival compared with large duct patients.
Furthermore, no small duct patients developed cholangiocarcinoma, as did 11% of the large duct patients.
Dr Björnsson's team concluded, "Patients with small duct PSC seem to have a good prognosis in terms of survival and development of cholangiocarcinoma".
"Small duct PSC progresses to large duct PSC in a small proportion of patients".