Liver Transplant for Patients With Neuroendocrine Tumor: A Report of 2 Exceptional Cases and Literature Review.

Patients with neuroendocrine tumors with unresec-table liver involvement can benefit from liver transplant. There is a specific set of guidelines for neuroendocrine tumors with liver metastasis that involve less than 50% of the liver. However, beyond those guidelines, there are reports of exceptional criteria patients who benefited from liver transplant. Here, we present 2 unusual cases of patients with exceptional circumstances and with neuroendocrine tumors who underwent liver transplant. The first case describes a patient with an extremely rare neuroen-docrine tumor of the proximal common bile duct that caused liver biliary cirrhosis. The patient underwent tumor resection and liver transplant concurrently. The second case describes a patient with a neuroendocrine tumor of unknown primary origin with more than 50% hepatic involvement who received a liver transplant after downstaging. In our center, patients with unresectable hepatic metastases from neuroendoc-rine tumors are currently selected for liver transplant based on well-established criteria. However, these 2 cases did not meet the criteria for consideration of liver transplant; thus, multidisciplinary team sessions were held to discuss these 2 cases. After a period of nonsurgical treatment and evaluation of the tumor behavior, we selected the patients as candidates for liver transplant based on the favorable tumor behavior and favorable response to treatment. For both patients, we did not observe any signs of tumor recurrence during follow-up. The outcomes were acceptable, and the patients tolerated treatment well. Considering the favorable tumor pathology (G1 phase and low Ki67 index), we suggest that more studies should be conducted to evaluate the outcomes of patients with low-grade tumors and that the criteria for patients with low-grade tumors could be extended based on such future data.