A case of hepatic segmental atrophy mimicking spontaneously necrotized hepatocellular carcinoma.

We report a rare case of hepatic segmental atrophy that was initially suspected to be hepatocellular carcinoma (HCC). An 80-year-old man presented with a new 3 cm hepatic lesion that met LI-RADS-5 criteria. However, follow-up CT performed 1 month later showed loss of arterial hyperenhancement, progressive delayed peripheral enhancement, and a reduction in lesion size. MRI subsequently demonstrated high signal intensity on T2-weighted and diffusion-weighted images, without true diffusion restriction. Based on these imaging features, spontaneous necrosis of scirrhous-type HCC was suspected, and surgical resection was undertaken. Histopathological examination revealed hepatic segmental atrophy with no evidence of malignancy. Segmental atrophy can closely mimic HCC on imaging, potentially leading to misdiagnosis and unnecessary surgery. Careful evaluation of atypical features-such as the absence of true washout, lack of restricted diffusion, disproportionate capsule-like structures, and progressive morphological changes-may assist in distinguishing segmental atrophy from malignancy.