Primary hepatic carcinoid and neuroendocrine carcinoma: Clinicopathological and immunohistochemical study of five cases

Primary hepatic carcinoid and neuroendocrine carcinoma (NEC) are rare tumor s. We experienced three carcinoids and two NEC originating in the liver dur ing the past 25 years and attempted to elucidate the clinicopathological an d immunohistochemical features of these tumors. The patients had no endocri ne symptoms despite two of them having elevated plasma serotonin, Three of the five patients died of the tumor after operation with an average surviva l time of 20.6 months. All tumors were large (up to 26 cm in diameter), fou r of them solitary and one multinodular, and were not associated with liver cirrhosis. The carcinoid tumors showed insular, trabecular or glandular ar rangement of argyrophilic cells, whereas in the NEC this histological patte rn was distorted. Immunohistochemically the tumors showed expression of chr omogranin A (all cases), chromogranin B (three cases), pancreastatin and ch romostatin (four cases, respectively), prohormone convertase PC3 (three cas es), carcinoembryonic antigen (CEA) and CA19-9 (two cases), cytokeratin 56 kDa (three cases), 160 kDa neurofilament (two cases) and neuron-specific en olase (two cases). Serotonin and glucagon were sporadically detected in two tumors. The most useful marker to confirm the diagnosis was chromogranin A , which was cleaved to pancreastatin and chromostatin in the tumor tissue, and was more reliable than other markers of neuroendocrine differentiation.