Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare tumors originating from neuroendocrine cells. Due to lack of neuroendocrine symptoms and specific radiographic characteristics, PHNETs are challenging to differentiate from other liver tumors.

This case involved a 67-year-old male who was admitted with a discovered hepatic mass and a suspicious lung lesion. Primary hepatic carcinoma was initially speculated based on the characteristic magnetic resonance imaging findings. The patient underwent a laparoscopic right partial hepatectomy, and subsequent immunohistochemical examination revealed a HNET. To exclude other potential origins, a positron emission tomography-computed tomography scan and gastrointestinal endoscopy were performed, leading to a final diagnosis of PHNETs. Then we conducted a literature review using the PubMed database, identifying 99 articles and 317 cases related to PHNETs. The characteristics, diagnostic methods, and treatment of PHNETs have been described. Finally, we elaborate on the presumed origins, pathological grades, clinical features, diagnosed methods, and treatments associated with PHNETs.

The diagnosis of PHNETs was primarily an exclusionary process. A definitive diagnosis of PHNETs relied mainly on immunohistochemical markers (chromogranin A, synaptophysin, and cluster of differentiation 56) and exclusion of primary foci in other organs. Radical surgery was the preferred treatment for early-stage tumors.

• Primary hepatic neuroendocrine tumors
• Pulmonary nodule
• Neuroendocrine neoplasms
• Liver
• Surgical resection
• Case report

• case report
• follow-up
• liver
• neuroendocrine tumors
• recurrence

• National Natural Science Foundation of China

• Classification
• Digestive tract
• Neuroendocrine neoplasm
• Terminology
• World Health Organization

• Humans
• Neuroendocrine Tumors/pathology
• Carcinoma, Neuroendocrine/pathology
• World Health Organization
• Gastrointestinal Tract/pathology
• Pancreatic Neoplasms/pathology

• Case report
• Hepatic resection
• Liver primary neuroendocrine tumor

Different histopathological manifestations of focal liver lesions show varying common and uncommon imaging findings and some pathologies may show similar appearance despite of different histopathology. It is necessary to characterise focal liver lesions accurately as not only benign and malignant lesions are managed differently, but also certain benign lesions have differing management. These lesions are increasingly being detected due to rapid growth of use of cross-sectional imaging as well as improvement in image quality and new imaging techniques. Contrast enhanced magnetic resonance imaging (MRI) is considered the gold standard technique in characterising focal liver lesions. Addition of gadoxetic acid has been shown to significantly increase diagnostic accuracy in the detection and characterization of liver abnormalities. Classic imaging characteristics of common liver lesions, including their behaviour on gadoxetic acid enhanced MRI, have been described in literature over recent years. It is important to be familiar with the typical aspects of these lesions as well as know the uncommon and overlapping imaging features to reach an accurate diagnosis. In this article, we will review the well-described characteristic imaging findings of common and rare focal liver lesions and present several challenging cases encountered in the clinical setting, namely hepatocellular adenoma, focal nodular hyperplasia, hepatic angiomyolipoma, hepatocellular carcinoma, intrahepatic cholangiocarcinoma, neuroendocrine tumours as well as a pleomorphic liposarcoma of the liver.

• Indeterminate liver lesions
• Magnetic resonance imaging
• Gadoxetic acid
• Hepatobiliary phase
• Hepatocellular carcinoma

• Diagnosis
• Laparoscopic hepatectomy
• Liver neoplasms
• Primary hepatic neuroendocrine tumor

We report an unusual presentation of primary hepatic neuroendocrine tumor which was initially misdiagnosed as intrahepatic cholangiocarcinoma. The diagnosis was only revealed after a major liver resection by histopathology. With adjuvant lanreotide injection, the patient survived for more than 16 months after the operation without tumor recurrence. Diagnosis of this rare tumor has been a major challenge and we emphasize the importance of a preoperative diagnosis. Surgical resection remains the mainstay for curative treatment, while peptide receptor radionuclide therapy is an emerging treatment option which has provided promising results.

• Carcinoid tumor
• Liver neoplasm
• Primary hepatic neuroendocrine tumor

Primary hepatic neuroendocrine tumors (PHNETs), a group of neuroendocrine neoplasms, are extremely rare. There are only few case reports about PHNETs in the literature. The lack of large samples and multicenter research results in poor diagnostic and therapeutic approaches.

To discuss the clinical characteristics, diagnosis, and treatment of PHNETs and risk factors related to survival.

We retrospectively analyzed the clinical data, imaging features, immunohistochemistry data, and treatment efficacy of 40 patients who were pathologically diagnosed with PHNETs and admitted to The First Affiliated Hospital of Zhengzhou University from January 1, 2014 to November 15, 2019. Finally, survival analysis was performed to identify the risk factors for survival.

The main symptoms and signs included intermittent abdominal pain (19 patients, 47.5%) and bloating (8 patients, 20.0%). The positive rates of tested tumor markers were recorded as follows: Carbohydrate antigen 19-9 (CA19-9) (6 patients, 15.0%), CA72-4 (3 patients, 7.5%), carcinoembryonic antigen (7 patients, 17.5%), and alpha-fetoprotein (6 patients, 15.0%). Immunohistochemical staining results showed positivity for Syn in 38 (97.4%) of 39 patients, for chromogranin A in 17 (65.4%) of 26 patients, for CD56 in 35 (94.6%) of 37 patients, for AE1/AE3 in 28 (87.5%) of 32 patients, and for Ki-67 in all 40 (100.0%) patients. The overall survival rate was significantly related to the tumor grade, AE1/AE3, and Ki-67. No significant correlation was found between other parameters (age, gender, tumor number, tumor size, metastasis, and treatment) and overall survival.

Higher grade, negative AE1/AE3, and higher Ki-67 are associated with a worse survival rate. Kinds of treatment and other parameters have no significant influence on overall survival.

• Neuroendocrine tumors
• Primary hepatic neuroendocrine tumors
• Diagnosis
• Survival analysis
• Tumor grade
• Treatment

• carcinogenesis
• hemangioma
• hepatic cancer
• surgical oncology

• Cholangiocarcinoma
• Neuroendocrine tumor
• Primary hepatic MiNEN

•

Primary hepatic neuroendocrine tumors are rare neoplasms, with less than 200 cases reported.

Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare, having less than 200 cases reported in the literature.

A 51-year-old woman presenting with mild intensity sharp pain in the upper abdomen that started 4 years ago. Preoperative Magnetic Resonance Imaging (MRI) suggested hepatocellular adenoma. Surgical exploration found a tumor occupying the whole segment IV of the liver, therefore a left hepatectomy was performed. Pathology and immunohistochemistry indicated to be a low-grade neuroendocrine tumor of the liver. The patient is enjoying a good quality of life, free of disease, presenting no signs of recurrence nor metastases 12 months after the procedure.

The clinical presentation of PHNETs is non-specific and its radiologic features are intensely diversified, frequently leading to misdiagnosis of other hepatic neoplasms.

• Diagnostic imaging
• Immunohistochemistry
• Liver neoplasms
• Neuroendocrine tumors

• liver
• neuroendocrine neoplasm
• primary

• Adult
• Aged
• Aged, 80 and over
• Antigens, Tumor-Associated, Carbohydrate/blood
• Female
• Hepatectomy/methods
• Hepatectomy/statistics & numerical data
• Humans
• Liver Neoplasms/mortality
• Liver Neoplasms/pathology
• Liver Neoplasms/surgery
• Male
• Middle Aged
• Neoplasm Grading
• Neoplasm Recurrence, Local
• Neuroendocrine Tumors/mortality
• Neuroendocrine Tumors/pathology
• Neuroendocrine Tumors/surgery
• Operative Time
• Prognosis
• Retrospective Studies
• Risk Factors
• Survival Rate