Extrahepatic Biliary Precancerous Lesions associated with Choledochal Cyst

Han, Sang Jin; Chang, Hee Jin; Park, Seong Heum; Choi, Kyong Woo

Abstract

BACKGROUND: Carinoma arising from the choledochal cyst is rare but well known complication, the mechanism of which is, however, still unclear. This study is intended to analogize the mechanism of carcinogenesis in choledocahl cyst from the changes in the cyst epithelium according to the age groups.
MATERIALS AND METHODS
This retrospective study included 19 cases of choledochal cysts and was performed by comparing 6 cases of group I patients(age less than 20) to 13 cases of group II patients(age 20 or more).The records of both group patients were reviewed for demographic and clinical features. Histopathologic findings and immunoreactivities for p53 were comparatively analyzed.
RESULTS
In group I, epithelial changes of chronic inflammation, regeneration atypia, hyperplasia, intestinal metaplasia and dysplasia were found in 6, 4, 5, 1 and 3 cases, respectively. In group II, there were 12 chronic inflamation, 5 regeneration atypia, 7 hyperplasia, 1 intestinal metaplasia, and 11 dysplasia including 4 high grade and 7 low grade dysplasia. There were also 3 carcinomas arising from the cyst in group II. p53 immunoreactivities were only found in those with dysplasia and carcinoma.
CONCLUSIONS
Intestinal metaplasia presents in only 2 cases. On the other hand, dysplasia is one of the predominant findings in the epithelium of the cysts. These findings suggest carcinogenesis in choledochal cyst presumably follow de novo pathway(repeated injury/regeneration - dysplasia - carcinoma) rather than metaplasia - dysplasia - carcinoma sequence.