Primary neuroendocrine tumors and primary neuroendocrine carcinomas of the liver: a proposal for a multidiscipline definition

Primary Hepatic Neuroendocrine Tumor: A Case Report and Literature Review

Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare and account for about 0.3% of all neuroendocrine tumor cases. Resection is usually difficult because they are usually diagnosed in the late stages. We report the case of a patient diagnosed with PHNETs, initially classified as unresectable but then underwent a successful left hepatectomy. PHNETs are rare malignant tumors, and a high index of suspicion is warranted for the diagnosis after excluding the presence of a primary extrahepatic lesion. Radical hepatectomy can be curative when feasible along with a combination of multiple treatments that improve the prognosis.

Comparison of primary hepatic neuroendocrine tumors and non-hepatitis B non-hepatitis C hepatocellular carcinoma on contrast-enhanced ultrasound

Objective

The purpose of this study was to compare the sonographic features of primary hepatic neuroendocrine tumors (PHNETs) to those of non-hepatitis B and non-hepatitis C hepatocellular carcinoma (NBNC-HCC) on contrast-enhanced ultrasound (CEUS).

Materials and methods

Fourteen patients with a mean age of 56.9 ± 12.2 (SD) years with histopathologically confirmed PHNET were included in the study. Twenty-eight patients with a mean age of 58.5 ± 10.4 years with histopathologically confirmed NBNC-HCC were randomly selected as the control group. The clinical data, conventional ultrasound and CEUS features were retrospectively analyzed between PHNET and NBNC-HCC.

Results

PHNET was more common in women (57.1%, 8/14 cases), and NBNC-HCC was more common in men (75.0%, 21/28) (P=0.040). No significant differences were observed in etiology, tumor marker, and liver function between the two group (P>0.05). Conventional ultrasound revealed that the tumor size of PHNET (10.1 ± 4.7 cm) was larger than that of NBNC-HCC (5.9 ± 3.8 cm) (P=0.006). NBNC-HCC was predominantly hypoechoic, while the echogenicity of PHNET varied (P=0.001). On CEUS, 57.1% (8/14) of PHNETs showed heterogeneous hyperenhancement, whereas 77.0% (21/28) of NBNC-HCC presented homogeneous hyperenhancement (P=0.015). Furthermore, 35.7% (5/14) of PHNETs showed early washout (onset of washout <60 s), which was significantly different from that of NBNC-HCC (3.7%, 1/28) (P=0.005).

Conclusion

CEUS is helpful in discriminating between PHNET and NBNC-HCC. PHNETs mainly present as a single mass with a large size (>10 cm) in the liver. The CEUS showed that most PHNETs exhibited heterogeneous enhancement in the arterial phase, washout in the portal venous and late phases and early washout being more likely than NBNC-HCC. However, more imaging features need to be evaluated in a larger sample.