[Primary neuroendocrine carcinoma of the liver. From carcinoid tumor to small-cell hepatic carcinoma: case reports and review of the literature].

Primary hepatic neuroendocrine tumors are rare neoplasms. While primary hepatic carcinoid tumors (PHCT) are well-differentiated tumors, primary hepatic small-cell carcinomas (PHSCC) represent the poorly differentiated end of the spectrum of neuroendocrine carcinomas. The first patient, suffering from PHCT, has had a follow-up for 32 years and is still alive. Within this time, the tumor relapsed 4 times with unchanged histology and immunohistochemistry features. The second patient suffered from small-cell carcinoma of the liver. There were no risk factors for a hepatocellular carcinoma. An extensive preoperative and postoperative diagnostic investigation could rule out an extrahepatic primary site. Immunohistochemically the tumor was negative for Hepar-1, AFP, TTF1 and CDX2 but reacted positively with CD56 and sporadically with the keratins 8, 18 and 20. A neuroendocrine PHSCC was diagnosed. After neoadjuvant cytostatic treatment the carcinoma was completely extirpated and 18 months after treatment the patient is healthy.PHCT and PHSCC have to be clearly separated from hepatocellular and cholangiocellular carcinomas. Exclusion of an extrahepatic primary site requires an accurate and synoptic analysis of clinical, radiologic and pathologic findings. Surgical resection is the treatment of choice.