[Epithelioid cell granuloma of the liver mimicking a primary phrenic tumor]

We here report an epithelioid cell granuloma of the liver, imaging of which mimicked a phrenic tumor. A 75-year-old woman was admitted to the hospital for evaluation of an abnormal shadow in the left lower lung field on a chest X-ray. Surgery was performed for a suspected schwannoma arising from the phrenic nerve or a primary diaphragmatic tumor based on chest computed tomography(CT) and magnetic resonance imaging (MRI). The intra-operative findings showed that the tumor did not originate from the diaphragm but from the left lobe of the liver with feeding vessels from the liver. Securing a sufficient margin, the tumor was surgically resected as a primary liver tumor. Histologically, the tumor was diagnosed as an epithelioid cell granuloma of the liver. It is sometimes difficult to discriminate organs from which tumors developing around the diaphragm because of the difficulty to perform biopsy or the presence of many candidate organs neighboring the diaphragm.