Hepatic Angiomyolipoma With Hemorrhagic Degeneration: A Case Report

Hepatic angiomyolipoma is a rare benign tumor that often mimics hepatocellular carcinoma on imaging.Here, we report a rare case of hepatic angiomyolipoma with extensive hemorrhagic degeneration, resulting in a large hemorrhagic component that mimicked a complicated cystic neoplasm.A 43-year-old woman presented with mild abdominal distension, and imaging revealed a 16-cm multiloculated cystic mass in the left hepatic lobe.Computed tomography revealed a thick, enhancing wall and septa with hyperattenuating internal fluid.On gadoxetic acid-enhanced magnetic resonance imaging, arterial enhancement was observed along the thick wall, and a subtle opposedphase signal drop indicated a small fat component that was initially missed.Laparoscopic left lobectomy was performed under suspicion of a malignant cystic neoplasm.Histopathological examination revealed an angiomyolipoma composed of thick-walled vessels, spindle-shaped muscle bundles, and scant adipocytes, with human melanoma black 45 positivity and absence of an epithelial lining, consistent with hemorrhagic degeneration.This case highlights how hemorrhagic degeneration can pose a significant diagnostic challenge by masking the typical features of hepatic angiomyolipoma, leading to diagnostic confusion with complicated cystic tumors.