Choledochal cysts-Classification, physiopathology, and clinical course

Although biliary canal cysts were first described around the 1720s, the aetiology, physiopathology, natural course, and treatment options of the disease remain controversial. These cysts are becoming more common and can now be more easily diagnosed thanks to recent developments in imaging methods. Nevertheless, if left un-diagnosed, the risk of progressive complications such as spontaneous perforation, cholelithiasis, choledocholi-thiasis, cholangitis, secondary biliary cirrhosis, portal hypertension, and development of malignancies should be considered. In this review, we discuss the epidemiology, classification, physiopathology, carcinogenesis, and clinical course of biliary cysts. Introduction Choledochal cysts (CCs) are rare medical conditions, which are congenital cystic dilatations of any portion of the bile ducts, most often occurring in the main portion of the common bile duct. Although choledochal cysts are considered a disorder of childhood and infancy, the ages in reported cases range from newly born to 80 years old; however 60% of such cysts are diagnosed in patients less than 10 years old [1-6]. Epidemiology Choledochal cysts (CCs) are extremely rare with an incidence of about 1/100–150,000 in Western societies. The disease affects 1 in 13,500 live births in the USA and 1 in 15,000 live births in Australia. It is seen more fre-quently in Asians; two out of three cases are of Japanese origin despite the reported incidence of 1/1,000. There is significant female gender predominance (F/M: 3–4/1). The cause of this female and Asian origin predomin-ance is unknown [6]. Classification Alonso-Lej defined three types of biliary dilatations in 1959; this classification system has since been widely accepted. Todani expanded this classification in 1977 and divided the CCs into five subgroups. Todani re-modified the classification to include pancreatic junctional abnormalities, and the resulting system became the final and most commonly used classification method [6] (Table 1) (Figure 1). According to the Todani classifi-cation, CCs are classified as follows: Correspondence to: Mustafa Yener Uzunoglu, Sakarya Üniversitesi Egitim ve Arastırma Hastanesi, Adnan Menderes Cad. Sağlık Sok. No: 195 Adapazarı, 54100, Sakarya, Turkey, Tel: +905056503394, E-mail: [email protected]