Bronchogenic Cyst in the Liver Mimicking Metastasis of Colorectal Carcinoma: A Case Report and Review

Introduction: Carcinomas of the colon and rectum are the third most common cancer entity in the world and bear a high risk of synchronous (25%) or metachronous (50%) hepatic tumor seeding. For therapeutic decisions the differential diagnosis between benign and malignant hepatic lesions in the computer tomography scan is of major importance. We herein discuss congenital hepatic cysts derived from the primitive foregut as potential differential diagnosis for hepatic metastases from a colorectal primary tumor. Case presentation: A caucasian, 56-year old female patient with the initial diagnosis of an adenocarcinoma of the rectum had initially been treated by an anterior rectum resection and hemihepatectomy due to synchronous hepatic metastases (pT3 pN1(2/13), G2, pM1(HEP), L1, V0, pR0) in a curative intention. The follow-up staging after 2 years showed recurrent liver metastases. A local resection of the hepatic foci was performed. One of three lesions was classified as a classical ventral foregut derived bronchogenic cyst located subcapsularly in the liver. A follow-up resection of pulmonary metastases was performed 13 months later. The patient is still alive and healthy 68 months after the primary operation. Conclusions: For the diagnosis and treatment of hepatic metastases of colorectal carcinomas it is very useful to know potential differential diagnoses in radiographic imaging. Foregut derived cysts can be histologically subclassified into Ciliated Hepatic Foregut Cysts and Bronchogenic Cysts. While Ciliated Hepatic Foregut Cysts are known to be located in the liver, we present the rare case of a Bronchogenic Cyst, which was located in the liver parenchyma.