A Rare Anomaly of Biliary System: MRCP Evidence of a Cystic Duct Cyst

Abstract

Cystic duct cysts are a rare congenital anomaly. While the other bile duct cysts (choledochus and the intrahepatic bile ducts) are classified according to the classification described by Tadoni, there is no classification method described by the cystic duct cysts, although it is claimed that the cystic duct cysts may constitute a new “Type 6” category. Only a limited number of patients with cystic duct cysts have been reported in the literature. The diagnosis is usually made in the neonatal period or during childhood. The clinical symptoms are nonspecific and usually include pain in the right upper quadrant and jaundice. The condition may also present with biliary colic, cholangitis, cholelithiasis, or pancreatitis. In our case, the abdominal ultrasonography (US) performed on a 6-year-old female patient who presented with pain in the right upper quadrant pointed out an anechoic cyst at the neck of the gall bladder. Based on the magnetic resonance cholangiopancreatography (MRCP) results, a cystic dilatation was diagnosed in the cystic duct. The aim of this case-report presentation was to discuss the US and MRCP findings of the cystic dilatation of cystic duct, which is an extremely rare condition, in the light of the literature information.

Isolated cystic duct cyst with associated stones in a 4-month-old boy

“…Isolated cystic duct cysts are very rare; with only around 20 cases previously reported in the literature, their incidence cannot be reasonably estimated [ 2 3 4 5 6 7 8 ]. Serena Serradel et al [ 4 ] and Bode and Aust [ 2 ] initially misdiagnosed such cysts as Todani type II choledochal cysts, and Loke et al [ 3 ] also mentioned that the case they encountered resembled a type II cyst.…”

Cholangiocarcinoma Arising from a Type VI Biliary Cyst: A Case Report and Review of the Literature

“…Type VI biliary cyst can be encountered in different forms. The cystic dilatation can be limited to the cystic duct either fusiform or saccular without any associated findings in the other bile ducts [ 3 , 5 , 6 , 9 , 10 ] or can be accompanied by fusiform common bile duct dilatation with varying size of communication between the cyst and dilated CBD (see [ 5 , 10 , 11 ], Figure 4 ).…”

“…It can show the presence of an associated cancer and is useful for staging. The disadvantages are high-dose radiation exposure and contrast agent administration especially in children [ 1 , 4 , 5 , 9 , 13 ].…”

Another Type of Choledochal Cyst Beyond the Todani Classification

“…The classification has changed from the 3 types described by Alonso-Lej to 5 types described by Todani, but these classifications do not include dilatation of the cystic duct. Some authors [2][3][4] refer to this entity as the sixth type of choledochal cyst. There have been fewer than 16 cases reported in the English literature, mostly in sporadic case reports.…”

“…There have been fewer than 16 cases reported in the English literature, mostly in sporadic case reports. 2,3 We present a case of a type VI choledochal cyst and review the literature to determine the basis of diagnosis and optimal management.…”