Primary hepatic neuroendocrine carcinoma: an underdiagnosed entity.

Primary hepatic neuroendocrine tumors are rare. We report a case of a primary neuroendocrine carcinoma of the liver with a review of the literature. In earlier reports, all of these tumors were named hepatic carcinoids. We now recognize that they belong to a heterogeneous group of neoplasms, with microscopic appearance not necessarily predictive of biologic behavior. To our knowledge, only 55 cases have been reported in the English literature. This entity has probably been underreported because of the assumption that it represents a metastatic lesion. A search for an occult primary neuroendocrine tumor outside the liver must always be pursued.