Case Presentation: A 23 year old Caucasian female with no significant past medical history presented to clinic for evaluation of a recently diagnosed liver mass. The patient had previously been seen in the Neurosurgery clinic for complaints of numbness and tingling sensations in her bilateral lower extremities from her hips down. An MRI of the lumbar spine surprisingly did not demonstrate any spinal cord abnormalities, but incidentally revealed the liver mass. Discussion with the patients revealed no significant family history of cancers but social history was significant for a 5 pack year history of smoking. To evaluate the mass a CT scan abdomen with contrast was done which further characterized the liver mass as a large (8.2 x 8.2 x 9.2 cm) complex cystic lesion in the medial segment of the left hepatic lobe with a large enhancing soft tissue component (4.2 x 5.5 x 5.6 cm), highly suspicious for a biliary cystadenocarcinoma. The patient was admitted and admission vital signs were normal. Laboratory testing done prior to admission was non-significant with normal liver function tests, CA 19-9 and negative viral hepatitis serology’s. Complete resection of the cystic mass and concomitant cholecystectomy was performed. Pathology revealed a moderately differentiated adenocarcinoma, arising in a choledochal cyst with invasion of the gallbladder wall, confirming a tissue diagnosis of cholangiocarcinoma. The patient had an uncomplicated post-operative course and underwent neoadjuvant chemotherapy. Of interest was that all neurological symptoms resolved post-operatively in a week, though no diagnostic measures was sought for those complaints.

Discussion: This case highlights an uncommon congenital biliary tract anomaly that is a premalignant lesion. Choledochal cysts typically present in the Asian populous in younger aged females. Classical presenting features are abdominal pain, abdominal mass and jaundice once complications have happened i.e. malignant transformation with obstruction of the biliary tree. Though the incidence has been estimated to be as low as 1:100,000 to 1: 150,000, cholangiocarcinoma’s complicating long standing choledochal cysts have been well documented. Cholangiocarcinoma itself is a rare cancer affecting 2000-3000 people in the USA annually. The reported prevalence of cancer associated with a primary choledochal cyst, however, is high at 26% with presentation in the 3rd decade of life. Cholangiocarcinoma has a 5-year survival rate of only 15% for localized intrahepatic origin. 

Conclusions: Choledochal cysts are congenital premalignant lesions that can result in cholangiocarcinomas early in adulthood.While there are no screening guidelines for choledochal cysts, when “incidentally” detected, physicians should ensure that prompt surgical consultation is sought so that the lesion is completely resected to prevent malignancy in the future.