Introduction: In the World Health Organization histological classification of the liver tumor, peliosis hepatis is defined as a tumor-like lesion. The entity is characterized by the appearance of multiple cyst-like, blood-filled spaces within the liver parenchyma.
Case presentation: A 77-year-old Japanese man with prostate cancer was referred to our department because he was diagnosed as having two hepatic tumors. The tumors were confirmed to be peliosis hepatis by repeated needle biopsies and because of their atypical images by enhanced computed tomography and enhanced magnetic resonance imaging. Later these tumors grew rapidly, increased in number, and disseminated throughout his whole liver. We are now treating the patient conservatively due to his age and his existing medical conditions.
Conclusion: Peliosis hepatis is a rare hepatic benign tumor that should be considered in the differential diagnosis of multiple unknown liver tumors that are revealed by atypical radiological images.