Cyst-like extension of hepatic subcapsular bleeding caused by ruptured hepatocellular carcinoma into the bursa omentalis.

An 81-year-old man, who experienced upper abdominal pain after shoveling snow, was admitted to a local hospital where a computed tomography (CT) showed a cystic lesion adjoining the pancreas. He was transferred to our department for detailed investigations and treatment. On ultrasonography, a tumor of the caudate lobe of the liver, with which the cystic lesion was continuous, was seen. The tumor of the caudate lobe of the liver was enhanced in the early phase of the CT but was washed out in the delayed phase. Subsequently, T1-weighted and T2-weighted magnetic resonance imaging (MRI) images showed a low intensity and a high intensity, respectively. Because the cystic lesion was continuous with the tumor of the caudate lobe of the liver, its CT value was higher than that of water, and both the T1-weighted and T2-weighted MRI images showed a high intensity, which was attributed to a hematoma. Examination of the image suggested that rupture of a hepatocellular carcinoma (HCC) might have caused intracavitary hemorrhage. After the HCC was treated by transcatheter arterial embolization therapy, the patient was discharged. Subsequently, tumor enlargement was confirmed, and surgical removal of the tumor was conducted at the hospital where the patient had originally presented. On histology, moderately differentiated HCC was diagnosed, but the cyst-like lesion was confirmed to be a hepatic subcapsular hematoma extending into the bursa omentalis. Although ruptured HCC often causes intraperitoneal bleeding, this rare case showed a cyst-like imaging finding in the form of a subcapsular hematoma within the bursa omentalis.