A Case of Hemorrhagic Hepatic Cyst with an Enhancing Mural Nodule That Was Difficult to Distinguish from Mucinous Cystic Neoplasm

Abstract

A 71-year-old woman was found to have a 7-cm hepatic cyst with a mural nodule in segment 7 in 2018. She was referred to our department due to an increase in the tumor marker CA19-9 and enlargement of the mural nodule on the cyst wall. At this point, the serum CA19-9 level was elevated to 740.2 U/ml. CT and US showed a hepatic cyst with an enhancing mural nodule on the wall. The cyst was suspected to be a hemorrhagic hepatic cyst or a mucinous cystic neoplasm (MCN) of the liver. Extended right posterior sectionectomy was performed, and a pathological examination ultimately diagnosed a hemorrhagic hepatic cyst. The CA19-9 level normalized immediately after the operation. MCN of the liver is a rare disease, and complete resection can result in a good prognosis. However, cases with invasion or dissemination have a poor prognosis. Hemorrhagic hepatic cysts are often similar to MCN in imaging, making preoperative differentiation difficult. Hepatectomy can be considered as a diagnostic and therapeutic option when malignancy cannot be ruled out.