Diffuse parenchymal metastasis is an unusual pattern of liver metastasis that is capable of causing liver failure. In the present study, the authors describe malignant infiltration of the liver by primary breast carcinoma in an autopsy of a 49-year-old female who had a rapid onset of liver failure and died after three weeks. Ultrasonography and computed tomography (CT) scans of the abdomen, as well as macroscopic examination, failed to detect liver metastasis; while microscopic examination revealed diffuse tumor cells with a loss of E-cadherin expression infiltrating into the liver parenchyma. The prognosis of liver failure associated with malignant infiltration is extremely poor; the survival time of patients is extremely low. Liver biopsy may be the most efficient technique for confirming the diagnosis during the patient's life.