Accessory liver lobe in the right thoracic cavity.

A healthy 42-year-old man presented to the hospital because of chest radiography performed during a medical checkup revealed a tumor. Contrast-enhanced computed tomography showed a tumor of 5 cm diameter just above the right diaphragm with blood flow from the portal vein. The patient was diagnosed with accessory liver lobe (ALL). No finding suggested malignancy, and he is being followed up. ALLs are usually found in the abdominal cavity, but they can also be found in the thoracic cavity. Although ALL is rare, it should be considered in patients presenting with intrathoracic tumors.