Abstract
A 57-year-old man was admitted to our hospital for severe anemia. Abdominal ultrasonography showed 4 tumors in S4, S3, S5 and S8 segments of the liver, with a diameter of 8, 1.5, 1.5 and 2 cm, respectively. The tumors in S3, S5 and S8 were diagnosed as cavernous hemangiomas because dynamic CT showed a pattern of marginal enhancement and a delay in wash-out of contrast medium. On the other hand, the tumor in S4 was difficult to diagnose although a cavernous hemangioma or hepatocellular carcinoma was suggested by dynamic CT. We then resected this tumor by left lobe hepatectomy without preoperative diagnosis. On macroscopic examination, the tumor was soft and encapsulated. Microscopic examination showed a few fat cells and many smooth muscle cells. Immunohistochemically, the smooth muscle cells were positively stained with anti-SMA and HMB-45. Thus the tumor was finally diagnosed as angiomyolipoma. It is of note that this tumor had hemangiomatous areas within the tumor and fibrous capsule. The atypical image findings of this tumor were most likely due to the scarcity of fat cells along with the presence of capsule and the hemangiomatous areas.
