Primary hepatic neuroendocrine tumors: multi-modal imaging features with pathological correlations

Relation between WHO Classification and Location- and Functionality-Based Classifications of Neuroendocrine Neoplasms of the Digestive Tract

Practice of neuroendocrine neoplasms (NENs) of the digestive tract, which comprise of a highly diverse group of tumors with a rising incidence, faces multiple biological, diagnostic, and therapeutic issues. Part of these issues is due to misuse and misinterpretation of the classification and terminology of NENs of the digestive tract, which make it increasingly challenging to evaluate and compare the literature. For instance, grade 3 neuroendocrine tumors (NETs) are frequently referred to as neuroendocrine carcinomas (NECs) and vice versa, while NECs are, by definition, high grade and therefore constitute a separate entity from NETs. Moreover, the term NET is regularly misused to describe NENs in general, and NETs are frequently referred to as benign, while they should always be considered malignancies as they do have metastatic potential. To prevent misconceptions in future NEN-related research, we reviewed the most recent terminology used to classify NENs of the digestive tract and created an overview that combines the classification of these NENs according to the World Health Organization (WHO) with location- and functionality-based classifications. This overview may help clinicians and researchers in understanding the current literature and could serve as a guide in the clinic as well as for writing future studies on NENs of the digestive tract. In this way, we aim for the universal use of terminology, thereby providing an efficient foundation for future NEN-related research.

Pediatric Ectopic Cushing Syndrome Caused by Hepatic Neoplasms: A Case Report and Systematic Review

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is rare in children, and localizing the source of EAS is often challenging. Here, we report EAS in an adolescent boy who presented with Cushingoid features and had endogenous ACTH-dependent hypercortisolism on hormonal evaluation. Abdominal ultrasound and CT revealed a hepatic lesion with characteristics suggestive of hemangioma, whereas the lesion was tracer non-avid on ⁶⁸Ga-DOTANOC positron emission tomography/CT. A regional sampling of ACTH was done to confirm the hepatic lesion as the source of EAS, and a definitive ACTH gradient was observed between the hepatic vein and the right internal jugular vein. Further, a preoperative biopsy of the lesion revealed a small round cell tumor with positive immunostaining for ACTH and synaptophysin, suggestive of a neuroendocrine tumor. The patient was managed with partial hepatectomy, resulting in hormonal and clinical remission of Cushing syndrome. In a systematic review of pediatric EAS due to primary hepatic tumors (n = 11), calcifying nested stromal epithelial cell tumors were the most common. EAS-associated hepatic tumors were larger (≥10 cm) except benign primary hepatic neuroendocrine tumors (PHNET). The latter were misdiagnosed as hemangioma in two cases by anatomical imaging but correctly diagnosed by somatostatin receptor scintigraphy. Hepatic tumors causing EAS in children required extensive resection, except benign PHNET. Nevertheless, all benign tumors with an uncomplicated perioperative course demonstrated disease-free survival over a median follow-up period of two years.

Recurrent primary hepatic VIPoma treated with a combination of surgical resection and loco-regional therapy

Vasoactive intestinal peptide (VIP) secreting tumors (VIPomas) are insidious functional neuroendocrine tumors originating mainly from pancreatic islet cells. Hepatic localization is considered exceedingly rare as only few cases have been reported in the literature. Diagnostic and therapeutic management of this tumor is still not clearly codified and therefore represents a real challenge for clinicians. Herein we report a unique case of a primary hepatic VIPoma recurrence in a female patient 22 years after curative resection. The patient had two sessions of transarterial chemoembolization. Complete symptomatic improvement was achieved since the first day after the first session. This case highlights that long-term follow-up for patients with hepatic VIPoma is mandatory as recurrence could occur several years after curative surgical treatment.

Primary Hepatic Neuroendocrine Carcinoma with Thrombocytopenia Due to Diffuse Bone Marrow and Splenic Infiltration: An Autopsy Case

An 82-year-old man with fever and back pain was referred to our hospital and was thus found to be thrombocytopenic. A bone marrow biopsy revealed the diffuse infiltration of poorly differentiated neuroendocrine carcinoma (NEC). Computed tomography revealed a large hepatic mass. Considering the risk of bleeding due to thrombocytopenia, a needle biopsy was not performed. The patient rapidly deteriorated and died 10 days after presentation. An autopsy confirmed the diagnosis of primary hepatic NEC, with diffuse metastasis to the spleen, bone marrow, and systemic lymph nodes. This is an extremely rare case of NEC presenting with thrombocytopenia due to extensive bone marrow and splenic infiltration.

Three-in-one incidence of hepatocellular carcinoma, cholangiocellular carcinoma, and neuroendocrine carcinoma: A case report

BACKGROUND

Primary hepatic neuroendocrine carcinoma (NEC) is rare, and a combination with hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) is extremely rare. To date, only four combination cases have been reported. The present paper describes the fifth patient.

CASE SUMMARY

A 32-year-old Chinese man with chronic hepatitis B was hospitalized for persistent upper abdominal pain. Abdominal computed tomography (CT) examination revealed a liver mass. The tumor was located in the 7^th and 8^th segments of the liver, and CT and magnetic resonance imaging findings were consistent with the diagnosis of HCC. Laboratory examinations revealed the following: Alanine aminotransferase, 243 U/L; aspartate aminotransferase, 167 U/L; alpha-fetoprotein, 4519 μg/L. Laparoscopic right lobe hepatectomy was performed on the liver mass. Postoperative pathology showed low differentiation HCC plus medium and low differentiation CCA combined with NEC. One month after the surgery, the patient suffered from epigastric pain again. Liver metastasis was detected by CT, and tumor transcatheter arterial chemoembolization was performed. Unfortunately, the liver tumor was progressively increased and enlarged, and after 1 mo, the patient died of liver failure.

CONCLUSION

This is a rare case, wherein the tumor is highly aggressive, grows rapidly, and metastasizes in a short period. Imaging and laboratory tests can easily misdiagnose or miss such cases; thus, the final diagnosis relies on pathology.

Hepatectomy and pneumectomy combined with targeted therapy for primary hepatic neuroendocrine carcinoma: Case report and review of the literature

Primary hepatic neuroendocrine carcinoma (PHNEC) manifests as a rare type of liver tumor. PHNEC is not specifically clinical or radiographical and is often misdiagnosed and mistreated. Here, we present a case report of PHNEC in a 50-year-old woman who was admitted to our department with concealed pain in the right upper abdomen. The initial diagnosis was a probable hepatic space-occupying lesion with tumor bleeding. The patient was subjected to a partial right hemihepatectomy, cholecystectomy, partial resection of the lower lobe of the right lung, partial resection of the diaphragm, and resection of the right perirenal fat sac to alleviate her symptoms. After surgery, gene sequencing was performed to determine the possible cause of the condition. However, five months after discharge, the patient was hospitalized again because of retroperitoneal and peritoneal multiple metastases. Nine months after surgery, the patient died. This case is likely to aid in furthering our understanding of PHNEC to improve the future diagnosis and treatment of this disease.

Re-Recognizing the Cellular Origin of the Primary Epithelial Tumors of the Liver

The primary epithelial tumors of the liver (PETL) are composed of a series of heterogeneous tumors. Although the classification of PETLs has been updated several times by the World Health Organization, the cellular origins of some tumors in this family remain to be precisely depicted. In addition, certain tumors in different categories have similar histology, molecular phenotypes and biological characteristics, suggesting that they may have the same cellular origin. In this work, a narrative review method was adopted to review the relevant papers. By comparing the expression profiles of biomarkers of liver epithelium at different lineages and stages of differentiation, the cells-of-origin of some major members of the PETL family were reassessed. We propose that 1) hepatic adenomas, hepatocellular carcinomas (HCCs) and pure fetal hepatoblastomas (HBs) share the same spectrum in their cellular origin including the hepatocytic-committed progenitors (HCP) and their differentiated descendants. 2) Bile duct adenomas, peribiliary cysts and intrahepatic cholangiocellular carcinomas (ICCs) can share the same spectrum in their cellular origin including the cholangiocytic-committed progenitors (CCP) and their differentiated descendants. 3) The cells-of-origin of embryonal HBs include liver stem cells (LSCs), hepatoblasts, and transitional cells between them. Embryonal HB with small cell element, small cell undifferentiated HB and small cell neuroendocrine carcinoma of the liver can have the same or similar cells-of-origin from LSC. Embryonal HB lacking the small cell component of the LSC phenotype and presenting both hepatocytic and bile duct/ductule components may originate from actual hepatoblasts/hepatic progenitor cells (HPCs) as the combined HCC-ICC does. 4) Teratoid hepatoblastoma and mixed epithelial/mesenchymal HBs can be derived from the LSCs or even less committed extrahepatic pluripotent stem cell. 5) Many members of the PETLs family, including those derived from LSCs, hepatoblasts/HPCs, early HCPs and CCPs, have neuroendocrine potentiality. Except for those primary hepatic neuroendocrine tumor (PHNET) exhibit hepatocytic and/or cholangiocytic phenotypes, other PHNETs subtype may be derived from the descendants of LSC that differentiate towards the upper digestive tract, pancreas or other lineages.

Primary hepatic neuroendocrine tumour with multiple liver metastases: A case report with literature review

INTRODUCTION AND IMPORTANCE

To describe an unusual case with a primary hepatic neuroendocrine tumour (PHNET) with multiple liver metastases.

CASE PRESENTATION

We reported a 65-year-old woman with PHNET with multiple liver metastases. She was highly suspected of having primary liver cancer with multiple intrahepatic metastases before liver biopsy, but was diagnosed with PHNET with multiple liver metastases after histopathology and immunohistochemistry (IHC) examinations. The patient successfully underwent three times of transcatheter arterial chemoembolization (TACE), and is currently living in a good state without related complications.

CLINICAL DISCUSSION

Neuroendocrine tumors (NETs), also known as carcinoids or argyrophilic tumors, are very rare malignant tumors. The liver is the main metastasis site of NETs, but primary hepatic neuroendocrine tumors (PHNETs) are extremely rare. Histopathology and immunohistochemistry (IHC) examinations are still the main methods used for diagnosing NETs. There are no treatment guidelines for PHNETs, and surgical resection is generally the preferred treatment. For PHNET patients who are not suitable for surgery, TACE has been proven to be an effective alternative treatment that can effectively reduce the tumour burden and relieve symptoms, but the current evidence is still limited.

CONCLUSION

The clinical diagnosis of PHNET still faces great challenges, imaging examinations often lead to misdiagnosis, and its diagnosis mainly depends on histopathology and immunohistochemical examinations. For PHNET patients who are not suitable for surgery, TACE may be an effective alternative therapy.

Effects of tumor origins and therapeutic options on the prognosis of hepatic neuroendocrine tumors: A retrospective study

Hepatic neuroendocrine tumors (HNETs) are uncommon neoplasms that can be subdivided into 2 types: primary and metastatic HNETs. Due to its rarity, heterogeneity and complexity, the diagnosis, treatment modalities and prognosis are still controversial.This retrospective study reviewed the effects of tumor origins and therapeutic options on the prognosis of gastroenteropancreatic neuroendocrine tumors with liver metastasis (GEP-NETLM) and primary hepatic neuroendocrine tumors (PHNETs), providing additional evidence for clinicians evaluating patients.HNETs consisted of PHNETs and GEP-NETLM. GEP-NETLM (76.2%, 112/147) was more common, which was mainly manifested as multiple lesions in both lobes of the liver. PHNETs were relatively rare (23.8%, 35/147) and were mainly single lesion located in the right lobe of the liver. In patients with GEP-NETLM, primary tumor resection could prolong survival (P = .044). As the most widely used treatment method, systematic therapy alone could not achieve a satisfactory survival. However, the combination with hepatectomy or liver-directed therapy improved the prognosis (P = .023). As the main treatment, patients with PHNETs treated with local therapy could achieve a better prognosis (P = .049). Compared with PHNETs patients, GEP-NETLM patients with higher ki-67 index showed higher mortality and poorer prognosis (P = .006).Therefore, patients with PHNETs can be distinguished from GEP-NETLM by comprehensive imaging examinations and long-term follow-ups. The choice of appropriate treatment strategies can improve the prognosis of HNETs patients.

Unusual Primary Neoplasms of the Adult Liver: Review of Imaging Appearances and Differential Diagnosis

The radiological appearance of common primary hepatic tumors such as hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) is widely recognized. Hepatic masses with unusual histology are occasionally encountered, but seldom suspected on imaging. However, many possess characteristic imaging findings, which when assessed along with the clinical and demographic background and serum tumor markers, may enable a prospective diagnosis. This review attempts to familiarize the reader with the clinicopathological characteristics, imaging manifestations, and differential diagnosis of these unusual liver tumors in adults. Biphenotypic primary liver carcinoma is suspected in masses showing distinct areas of HCC and CCA-type enhancement pattern in cirrhotic livers. Fibrolamellar carcinoma occurs in young individuals without underlying chronic liver disease and shows a characteristic T2-hypointense scar frequently showing calcification. Perivascular epithelioid cell tumors are differentials for any arterial hyperenhancing mass in the noncirrhotic liver, particularly in patients with tuberous sclerosis. Multifocal subcapsular tumors showing target-like morphology, capsular retraction and "lollipop" sign are suspicious for epithelioid hemangioendothelioma. On the other hand, multiple hemorrhagic lesions showing patchy areas of bizarre-shaped arterial phase hyperenhancement are suspicious for angiosarcoma. Primary hepatic lymphoma (PHL) is suspected when patients with immunosuppression present with solitary or multifocal masses that insinuate around vessels and bile ducts without causing luminal narrowing. Intense diffusion restriction and low-level homogeneous or target-like enhancement are also ancillary features of PHL. Primary hepatic neuroendocrine tumor shows uptake on Ga-68 DOTANOC PET/CT. Although a straightforward diagnosis may be difficult in these cases, awareness of the characteristic imaging appearances is helpful in suspecting the diagnosis.

Primary hepatic neuroendocrine tumour masquerading as a giant haemangioma: an unusual presentation of a rare disease

Primary hepatic neuroendocrine tumour is an exceedingly rare entity. We hereby delineate the case of a 45-year-old Balti descent woman who hails from a land-locked village situated in the foothills of the Pakistani Himalayas. The patient presented to our medical centre with a hepatic mass. She underwent extensive diagnostic workup. The consistent findings of an abdominal CT scan, coupled with her clinical history, insinuated a preoperative diagnosis of atypical hepatic haemangioma. After a detailed discussion in a multidisciplinary meeting, a standard right hemihepatectomy was performed. She had an uneventful postoperative recovery and was discharged in stable condition after 1 week. Surprisingly, pathological examination and immunohistochemistry of the resected specimen divulged the diagnosis of a grade II primary hepatic neuroendocrine tumour. Her somatostatin-receptor scintigraphy and Gallium-68 DOTATATE positron emission tomography scan excluded residual hepatic or additional body lesions. Regular follow-ups over the past 4 years demonstrated unremarkable radiological findings with no recurrence to date.

Clinicopathological Characteristics and Survival Outcomes of Primary Hepatic Neuroendocrine Tumor: A Surveillance, Epidemiology, and End Results (SEER) Population-Based Study

BACKGROUND Primary hepatic neuroendocrine tumor (PHNET) is a rare primary liver tumor that remains poorly understood. Here, we explored the clinicopathological characteristics and survival outcomes of PHNET patients. MATERIAL AND METHODS PHNET patients diagnosed between 1988 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were enrolled in the cohort. Kaplan-Meier analysis was used to determine the survival outcomes. Multivariable Cox regression models were used to identify the risk factors for overall survival (OS) and disease-specific survival (DSS). RESULTS A total of 291 PHNET patients from the SEER database met the inclusion criteria for analysis. The majority of the patients were female (53.6%), white (77.7%), and married (49.5%). The 1-, 3-, and 5-year OS were 57.1%, 39.4%, and 30.2%, and the 1-, 3-, and 5-year DSS rates were 61.3%, 44.3%, and 36.7%, respectively. Multivariate Cox regression models showed that older age, unmarried status, poor differentiated grade, and no tumor-directed surgery were independent risk factors for poor OS and DSS. CONCLUSIONS Older age, unmarried status, poor differentiated grade, and no tumor-directed surgery were associated with poorer prognosis of PHNET. Surgical resection is an effective and reliable treatment method for patients with PHNET.

Hepatic neuroendocrine neoplasm: imaging patterns

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with distinct morphological and biological manifestations, the liver being the main organ affected by its metastases. However, primary hepatic involvement is quite rare. Hepatic NENs can have a variety of radiological presentation forms and can therefore mimic other lesions, making their diagnosis challenging. Nonetheless, certain imaging aspects allow NENs to be included among the main differential diagnoses of hepatic lesions and can guide the search for an extrahepatic primary site when the probable diagnosis is metastases.

Differentiation of hypervascular primary hepatic tumors showing hepatobiliary hypointensity on gadoxetic acid-enhanced magnetic resonance imaging

PURPOSE

To determine the imaging features that help differentiate hypervascular primary hepatic tumors showing hepatobiliary hypointensity on gadoxetic acid MRI.

METHODS

This study comprised 148 patients with pathologically proven hypervascular hepatic tumors who underwent gadoxetic acid MRI. Tumors included 23 atypical focal nodular hyperplasias (FNHs), 11 hepatocellular adenomas (HCAs), 15 neuroendocrine tumors (NETs), 25 intrahepatic cholangiocarcinomas (ICCs), and 74 hepatocellular carcinomas (HCCs). MRIs were analyzed for morphologic features, signal intensity, and enhancement pattern of the tumors to determine the differential features using multivariate logistic regression analysis. We evaluated the diagnostic performance of the MRI features for differentiating the five tumor types upon review by two observers.

RESULTS

Multivariate analysis revealed that reverse target sign on hepatobiliary phase in FNHs (p = 0.009), iso or hyperintensity on ADC map in FNHs and HCAs (p = 0.009, < 0.001, respectively), central hypointensity on arterial phase in NETs (p = 0.001), hepatobiliary target sign in ICCs (p = 0.002), the presence of septum and capsule in HCCs (all p < 0.001) were significant independent features of each tumor group over other tumor groups. Diagnostic accuracy for both observers was 98-98.6% for FNHs, 96.6-98% for HCAs, 97.3-98.6% for NETs, 90.5-94.6% for ICCs, and 85.8-93.2% for HCCs.

CONCLUSIONS

Ancillary MRI features established in our study can be helpful in the differentiation of hypervascular and hepatobiliary hypointense primary hepatic tumors on gadoxetic acid MRI.

Diagnosis of recurrent HCC: intraindividual comparison of gadoxetic acid MRI and extracellular contrast-enhanced MRI

PURPOSE

To compare the efficacy of magnetic resonance imaging (MRI) with hepatobiliary agents (HBA-MRI) and MRI with extracellular contrast agents (ECA-MRI) for detection of recurrent hepatocellular carcinoma (HCC) after multiple treatments.

METHODS

The institutional review board approved this retrospective study and waived the requirement for informed patient consent. A total of 135 patients with suspected HCC recurrence after 2-5 treatments (surgery, transarterial chemoembolization, and/or radiofrequency ablation) underwent both HBA-MRI and ECA-MRI within a 1 month interval. HBA-MRI and ECA-MRI were analyzed for HCC detection by two observers using a five-point scale. The diagnostic performances according to MRI modality were compared.

RESULTS

A total of 136 liver lesions (121 HCCs and 15 benign lesions; median size, 1.9 cm) were identified. ECA-MRI showed greater sensitivity (90.9% vs. 76.9% for observer 1; 91.7% vs. 78.5% for observer 2) and accuracy (91.2% vs. 78.7% for observer 1; 91.9% vs. 80.2% for observer 2) than HBA-MRI for both observers (P = 0.002, 0.003). Fifteen (12.4%) HCCs were correctly diagnosed with ECA-MRI but not with HBA-MRI by both observers. Interobserver agreement was excellent (0.885) for ECA-MRI and substantial (0.749) for HBA-MRI.

CONCLUSIONS

For detection of recurrent HCC, ECA-MRI was superior to HBA-MRI in terms of sensitivity and accuracy. Therefore, ECA-MRI could be the preferred imaging modality over HBA-MRI for assessing HCC recurrence following multiple treatments.

Primary Hepatic Neuroendocrine Carcinoma Treated with Doxorubicin and Cyclophosphamide in a Dog

A 7 yr, 6 mo old male neutered Australian cattle dog cross presented to a referral hospital with a large abdominal mass. An abdominal ultrasound revealed multifocal lesions throughout the liver, which were suspicious for intrahepatic metastasis, with no evidence of extrahepatic metastatic disease. Cytology indicated neoplasia of epithelial origin, with neuroendocrine neoplasia the primary suspicion. The patient was started on a maximally tolerated chemotherapy protocol of doxorubicin and metronomic cyclophosphamide. Stable disease was found on repeat abdominal ultrasounds, and the patient tolerated the protocol well. On completion of five doxorubicin doses, the dog was continued on metronomic cyclophosphamide and meloxicam. Progressive hepatic disease was found at 10 mo. The patient was euthanized 15.5 mo (465 days) after commencing treatment. Histopathology and immunohistochemistry (synaptophysin) performed on liver collected postmortem indicated (primary) hepatic neuroendocrine carcinoma. Primary hepatic neuroendocrine carcinomas are rare in dogs, and there is no standard of care for treatment. To the authors' knowledge, this is the first report of a primary hepatic neuroendocrine carcinoma treated with high-dose doxorubicin and metronomic cyclophosphamide.