Acute liver failure (ALF) is an uncommon disorder that leads to jaundice, coagulopathy, and multisystem organ failure [1]. Malignancy is an uncommon cause of ALF, and diffuse parenchymal metastases are a pattern that is capable of causing liver failure. Hematological malignancies are recognized to be the most common cause of diffuse parenchymal metastases, but this metastatic pattern has also been identified in many primary neoplasms, such as breast cancer [1]. The prognosis is very poor [1][2][3]. Recently, in a literature review performed by Mogrovejo et al. [2], 32 cases were characterized (only 25 % were diagnosed premortem, but with a statistically significant trend of increasing premortem diagnosis since 2000: p = 0.001); common signs included jaundice, hepatomegaly, shifting dullness, and bilateral leg edema; mean serum level of AST was 296.4 ± 204.0 U/l, ALT was 183.2 ± 198.9 U/l, and total bilirubin was 8.6 ± 8.3 mg/ dl. Authors reported also a new case of ALF from breast cancer (mixed ductal and lobular carcinoma) with hepatic metastases (demonstrated by liver biopsy) that occurred 21 years after original breast primary.We report too the case of a 35-year-old women, without any pathological history. Four years ago, she underwent demolitive surgery for invasive mixed ductal and lobular left breast cancer, G3, ER = 90 %, PgR = 0 %, MIB-1 = 20-30 %, HER2/NEU = 3?, pT1bpN0M0. She was treated with adjuvant chemotherapy with docetaxel (75 mg/m 2 ), carboplatin (AUC 6), and trastuzumab (8 mg pro kg for the first dose and 6 mg pro kg for subsequent doses) (TCH) each 21 days for six cycles, followed by the administration of three weekly trastuzumab (6 mg pro kg) for 1 year; she also started hormone therapy with tamoxifen at the dose of 20 mg/daily following chemotherapy (for 5 years total treatment provided) and enantone 3.75 mg/month. After 3 years, she presented with asthenia and right upper quadrant pain. At physical examination, jaundice and hepatomegaly were found; Eastern Cooperative Oncology Group (ECOG) performance status (PS) was 3. Abdominal ultrasonography revealed the presence of bone and liver metastases (several hypoechoic lesions in right and left hepatic lobe), ranging from 10 to 15 mm in maximum diameter as confirmed by the subsequent CT scan. Liver function test showed increased total and direct bilirubin of 5.0 and 2.5 mg/dl, respectively, AST (388 U/l), ALT (236 U/l), and cGT (449 U/l) serum levels (Table 1). Considering the young age and the bio-pathological features of the disease, we decided to start chemotherapy with weekly carboplatin (AUC 2), vinorelbine, and trastuzumab (2 mg pro kg). We have seen a progressive improvement in both the general condition of the patient (ECOG PS = 1) and the values of liver function. In particular, after 1 month of chemotherapy, values of liver function were nearly normalized: total bilirubin = 0.4 mg/dl, AST = 48 U/l, ALT = 60 U/l, and cGT = 88 U/l serum levels ( Table 1). The CT scan revealed a partial remission (PR) of liver metastases. After 6 months...