Analysis of B-ultrasound and contrast-enhanced ultrasound characteristics of different hepatic neuroendocrine neoplasm

High-frame-rate contrast-enhanced ultrasound findings of liver metastasis of duodenal gastrointestinal stromal tumor: A case report and literature review

BACKGROUND

Liver metastasis of duodenal gastrointestinal stromal tumor (GIST) is rare. Most reports mainly focus on its treatment and approaches to surgical resection, while details on its contrast-enhanced ultrasound (CEUS) findings are lacking. The diagnosis and imaging modalities for this condition remain challenging.

CASE SUMMARY

A 53-year-old Chinese man presented with mild signs and symptoms of the digestive tract. He underwent routine examinations after GIST surgery. Magnetic resonance imaging showed a 2.3 cm hepatic space-occupying lesion. All the laboratory test results were within normal limits. For further diagnostic confirmation, we conducted high frame rate CEUS (H-CEUS) and found a malignant perfusion pattern. Heterogeneous concentric hyper-enhancement, earlier wash-in than the liver parenchyma, and two irregular vessel columns could be observed at the periphery of the lesion during the arterial phase. Ultrasound-guided puncture biopsy was used to confirm the diagnosis of the lesion as liver metastasis of duodenal GIST. Imatinib was prescribed after biopsy, and the patient’s clinical course was monitored.

CONCLUSION

H-CEUS is useful for detecting microcirculation differences, wash-in patterns, and vascular morphogenesis and diagnosing liver metastasis of duodenal GIST.

Contrast-Enhanced Ultrasound Findings of Hepatocellular Carcinoma With Neuroendocrine Carcinoma: A Case Report

Hepatocellular carcinoma (HCC) with the concurrent occurrence of primary hepatic neuroendocrine carcinoma (NEC) of the liver is extremely rare. Preoperative diagnosis of HCC combined with NEC is very difficult. Here, we presented a case report of HCC combined with NEC. A 33-year-old male was admitted to our hospital due to focal liver lesion. To further the diagnosis, he received laboratory tests, conventional ultrasound, contrast-enhanced ultrasound (CEUS), and magnetic resonance imaging (MRI). Grayscale ultrasound showed a hypoechoic nodule with peripheral hypoechoic halo and central small patches of anechoic area in the hepatic segment VI, and the liver background was cirrhosis. In the CEUS, the solid component of the nodule was rapidly homogeneous hyper-enhancement in the arterial phase. Then, the enhancement of the nodule was washed out slowly and gradually; the nodule presented heterogeneously mild enhancement in the portal phase, and slight hypo-enhancement was showed in the late phase. The hypo-enhanced area was mainly located in the surrounding space. Meanwhile, there was a small piece of non-enhanced area within the lesion center in the whole three-phase imaging. MRI showed a lobular contoured mass in segment VI. The patient underwent middle liver resection, splenectomy, and cholecystectomy. The pathological diagnosis was a HCC with NEC. At the time of the preparation of this manuscript, the patient has been alive without recurrence or distant metastases for 6 months since the surgery. We mainly focus on the ultrasound imaging characteristics, especially its enhancement manifestations on CEUS. In this report, since this article is a case report, which is based on the clinical information of the patient and does not involve the patient's privacy, informed consent is not necessary. In addition, the patient agreed to publish the case. To the best of our knowledge, this report is the first to describe the CEUS patterns of the HCC combined with NEC. Herein, we report a case that provides novel insights that will improve clinicians' awareness of the clinical and ultrasound manifestations of this mixed tumor, resulting in improved diagnosis, treatment, and outcomes.

Contrast-Enhanced Ultrasonography Findings Correlate with Pathologic Grades of Pancreatic Neuroendocrine Tumors

The correlation of sonographic findings with pathologic grades of pancreatic neuroendocrine tumors (PNETs) remains unclear. This study aimed to evaluate the usefulness of sonographic features in diagnosing the pathologic grade of PNETs. Conventional and contrast-enhanced ultrasonography findings of PNETs diagnosed by surgical pathology from July 2010 to June 2020 were retrospectively reviewed. Sonographic features were compared among three pathologic grades of PNETs according to the World Health Organization 2010 classification. Ordinal regression models were constructed to evaluate the usefulness of the sonographic features in diagnosing the pathologic grade of PNETs. This study enrolled 93 participants with PNETs: 50 grade 1, 31 grade 2 and 12 grade 3. Multivariate ordinal regression analysis suggested that tumor size ≥2 cm (odds ratio [OR], 0.110; 95% confidence interval [CI], 0.020-0.606; p = 0.011), dilation of the main pancreatic duct (OR, 0.103; 95% CI, 0.025-0.430; p = 0.002), hepatic metastases (OR, 0.250; 95% CI, 0.072-0.869; p = 0.029) and hyper-enhancement in arterial phase (OR, 4.676; 95% CI, 1.656-13.206; p = 0.004) were significantly associated with the pathologic grades of PNETs. The accuracy of the ordinal logistic regression model in identifying grade 1, 2 and 3 PNETs was 77.4%, 67.7% and 90.3%, respectively. The findings suggest that sonographic features, including tumor size, pancreatic duct dilation and hepatic metastasis, as well as the enhancement level in arterial phase, may help identify different pathologic grades of PNETs.

Pancreatic neuroendocrine tumors G3 and pancreatic neuroendocrine carcinomas: Differences in basic biology and treatment

In 2017 the World Health Organization revised the criteria for classification of pancreatic neuroendocrine neoplasms (pNENs) after a consensus conference at the International Agency for Research on Cancer. The major change in the new classification was to subclassify the original G3 group into well-differentiated pancreatic neuroendocrine tumors G3 (pNETs G3) and poorly differentiated pancreatic neuroendocrine carcinomas (pNECs), which have been gradually proven to be completely different in biological behavior and clinical manifestations in recent years. In 2019 this major change subsequently extended to NENs involving the entire digestive tract. The updated version of the pNENs grading system marks a growing awareness of these heterogeneous tumors. This review discusses the clinicopathological, genetic and therapeutic features of poorly differentiated pNECs and compare them to those of well-differentiated pNETs G3. For pNETs G3 and pNECs (due to their lower incidence), there are still many problems to be investigated. Previous studies under the new grading classification also need to be reinterpreted. This review summarizes the relevant literature from the perspective of the differences between pNETs G3 and pNECs in order to deepen understanding of these diseases and discuss future research directions.