Hepatic NETs
Hepatic NETs
Primary hepatic neuroendocrine tumors (carcinoids) is an extremely rare type of neuroendocrine tumor, with somewhere between 60-90 cases reported in the literature. Metastatic neuroendocrine tumor from the gastrointestinal tract to the liver is far more common.
Clinical presentation
Some patients present with carcinoid syndrome. Elevated 5-HIAA and/or gastrin levels have been reported.
Pathology
Histologically, the tumor has features of classic neuroendocrine tumor (i.e. trabecular and pseudoglandular pattern) and dense core granules demonstrated by electron microscopy or by immunohistochemistry (i.e. positive staining by chromogranin antibody).
There is speculation that the tumor might arise from ectopic pancreatic tissue in the liver or through differentiation from biliary epithelium.
Radiographic features
Currently, there are no specific imaging features, and cases are diagnosed retrospectively. One case report described an imaging appearance on ultrasound and contrast-enhanced CT similar to focal nodular hyperplasia. Somatostatin-receptor nuclear medicine studies (In-111 pentetreotide (Octreoscan)) should be positive.
Given the rarity of the finding, a thorough investigation for an extrahepatic primary carcinoid tumor is necessary.
Treatment and prognosis
No standard treatment exists. Surgical resection has been performed.