Undifferentiated carcinoma of the liver: a case report with immunohistochemical analysis

Abstract

BACKGROUND Undifferentiated carcinoma (UC) of the liver is extremely rare, and its clinicopathological characteristics have not been fully elucidated. CASE PRESENTATION The present study reports the case of a 56-year-old male with UC of the liver. At 16 days post-admission, the patient suddenly succumbed due to intra-abdominal bleeding resulting from a ruptured liver. Macroscopic examination revealed that the hepatic parenchyma was almost completely replaced by innumerable minute nodules. Microscopically, the tumor demonstrated a diffuse proliferation of anaplastic cells that were positive for epithelial membrane antigen and neuron-specific enolase, suggesting neuroendocrine differentiation. Grimelius and Fontana-Masson staining were negative. Neuroendocrine markers were also negative, including chromogranin A, synaptophysin, and S-100 protein. Cytokeratin markers and mesenchymal markers were all negative. Tumor markers, such as α-fetoprotein and carcinoembryonic antigen, were also negative. CONCLUSIONS Although larger studies involving more patients are required to establish a therapeutic strategy, appropriate chemotherapy following an early diagnosis may be important to UC of the liver because the tumor behaves in an aggressive way.