Hepatic Pseudolipoma Mimicking Fat-containing Malignant Liver Tumor: A Case of Migration from the Pelvic Cavity

Background/Aim: Hepatic pseudolipoma is a rare, benign lesion composed of degenerating fat encapsulated beneath the liver capsule. Although typically believed to originate from detached epiploic appendages, its precise pathogenesis remains unclear. We report a case of histologically confirmed hepatic pseudolipoma that migrated from the pelvic cavity to the liver. Case Report: A 64-year-old woman with no history of liver disease underwent follow-up imaging after treatment for colonic diverticulitis and urinary lithiasis. A non-contrast computed tomography (CT) scan performed 1.5 years earlier showed no hepatic mass but, retrospectively, revealed two fat-attenuating masses with small calcifications in the pelvic cavity. At admission, contrast-enhanced CT demonstrated a newly emerged, well-defined, fat-containing lesion on the hepatic dome. Magnetic resonance imaging suggested a benign fatty lesion without diffusion restriction. Laparoscopy revealed a white, mobile mass emerging from a depression on the liver surface. Histopathological examination confirmed the diagnosis of a typical pseudolipoma. One of the previously identified pelvic lesions was presumed to have migrated transperitoneally to the liver surface. Conclusion: This is the first reported case of a histologically confirmed hepatic pseudolipoma that migrated from the pelvic cavity. Hepatic pseudolipomas may not be confined to the subcapsular space but can migrate freely within the abdominal cavity.