Liver transplant for neuroendocrine tumor metastatic to the liver: literature review and report of extirpation at 16-year recurrence.

: New information has demonstrated that there are few long-term disease-free survivors after a liver transplant for neuroendocrine tumors. All studies have limited follow-up to 10 years after a transplant. We present the case of a recurrent metastatic carcinoid in a patient 16 years after an orthotopic liver transplant. The subject initially presented with worsening chronic diarrhea, hypoglycemia, and confusion with massive hepatomegaly. The postoperative pathology report showed 80% to 90% of the liver tissue replaced by biopsy-proven synaptophysin-positive intrahepatic tumor with neuroendocrine differentiation. At the time of his liver transplant, he also underwent a distal pancreatectomy and splenectomy. Nuclear medicine tumor location studies, ultrasound, and computed tomography studies were performed at regular yearly intervals for 8 years on follow-up. Sixteen years after his orthotopic liver transplant, a retroperitoneal mass was detected showing neuroendocrine differentiation. Older studies focusing on an orthotopic liver transplant for highlighted clinical features would positively predict long-term survival. Older studies found the following features to be predictive of long-term survival in liver transplant for neuroendocrine tumors: age < 55 years, < 50% replacement of liver with metastatic neoplastic tissue and carcinoid type. These features were identified on multiple studies as positive predictors of disease-free survival. These studies were limited to, at most, 10-year follow-up. Newer studies have examined molecular features such as expression of E-cadherin and Ki-67 as positive predictors of long-term survival. However, no study has determined the full natural history of these tumors and for how long these patients should be followed. This anecdotal report highlights that late recurrence can occur.