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A Case of Hepatic Angiomyolipoma With Peritumoral Hyperplasia Difficult to Differentiate From Hepatocellular Carcinoma Preoperatively

Abstract Angiomyolipoma of the liver is a well-known benign tumor, but preoperative imaging diagnosis is often difficult because of variation in the proportions of its 3 components. We report an unusual case of angiomyolipoma with the imaging and pathological findings. In a 63-year-old woman, abdominal ultrasonography detected a mass in segment 4 of the liver. Contrast-enhanced ultrasonography showed a uniformly enhancing mass in the early vascular phase and a defect in the postvascular phase. Dynamic computed tomography and magnetic resonance imaging revealed a hypointensity in the center of the mass and ring enhancement at its periphery. The preoperative diagnosis was unclear, so a partial hepatectomy was performed. On pathological examination, the resected lesion had two components. The central portion of the mass consisted of anangiomyolipoma without adipose component. The peripheral portion of the lesion was composed of liver cell hyperplasia. The diagnosis was angiomyolipoma associated with peritumoral hepatocyte hyperplasia.