Liver Transplantation for High-Grade Primary Hepatic Neuroendocrine Tumor with Diffuse Liver Metastasis

Abstract

Gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are rare tumors arising from neuroendocrine cells of different parts of the gastrointestinal system including pancreas, small bowel, large bowel, and appendix. Primary hepatic NETs are very rare and more than 80% of NETs in the liver are metastatic from other primary sites [1]. Classification of GEP NET has been evolving during recent years. NET is now generally divided into welldifferentiated NET and poorly differentiated neuroendocrine carcinoma (NEC). Well-differentiated NET is classified as grade 1 (low grade) and grade 2 (intermediate grade) based on proliferative activity looking at mitotic count and Ki-67 index. Poorly differentiated NEC is classified as grade 3 (high grade) resembling small or large cell NEC of lung with worse prognosis than well-differentiated NET [2, 3]. Recently, a new category of NET with well-differentiated pathology but with Ki-67 index > 20% has been recognized and classified as grade 3 (G3). Irrespective of the tumor location, high-grade NETs have more dismal prognosis than lowgrade NET. Liver transplantation has been considered for treatment of G1 and G2 NET (low and intermediate grades) with non-resectable diffuse disease confined to the liver [4]. However, the treatment for high-grade NET is controversial and has not been standardized yet. Here in, we describe a patient with high-grade primary hepatic NET and diffuse liver metastasis that was successfully treated with liver transplantation.