Neuroendocrine tumors metastatic to the liver: How to select patients for liver transplantation?

Proliferation index (grading) of gastrointestinal NET as assessed by Ki67 immunocytochemistry in biopsies of liver metastases. Arrows indicate positive cells. (a) Well-differentiated carcinoid (Ki67: none or <2% cells/10 HPF); (b) low-grade malignant carcinoid (Ki67: 2–5% cells/10 HPF); (c) poorly-differentiated endocrine carcinoma (Ki67: >10% cells/10 HPF).

Diffuse hepatic metastases by low-grade malignant carcinoid limited to less than 50% of the hepatic parenchyma. The specimen belongs to a young girl with primary tumor removed in the terminal ileum; she is alive and well with no sign of recurrence 15 years after liver transplantation.