A case of solid-pseudopapillary neoplasm, focusing on contrast-enhanced endoscopic ultrasonography

Efficacy of Contrast-Enhanced Endoscopic Ultrasonography for the Diagnosis of Pancreatic Tumors

Endoscopic ultrasound can be useful for obtaining detailed diagnostic images for pancreatic disease. Contrast-enhanced harmonic endoscopic ultrasound has allowed to demonstrate not only microvasculature but also real perfusion imaging using second-generation contrast agents. Furthermore, endoscopic ultrasound fine-needle aspiration cytology and histology have become more ubiquitous; however, the risk of dissemination caused by paracentesis has yet to be resolved, and the application of less invasive contrast-enhanced endoscopic ultrasound for the differential diagnosis of pancreatic tumors has been anticipated. Contrast-enhanced harmonic endoscopic ultrasound can contribute to the differential diagnosis of pancreatic tumors.

Differentiation Between Solid Pseudopapillary Neoplasm of the Pancreas and Nonfunctional Pancreatic Neuroendocrine Neoplasm Using Endoscopic Ultrasound

OBJECTIVES

We investigated the utility of endoscopic ultrasound (EUS) for differentiating between solid pseudopapillary neoplasm of the pancreas (SPN) and pancreatic neuroendocrine neoplasm (PanNEN).

METHODS

A retrospective analysis was performed on 29 and 77 consecutive patients with pathologically proven SPN and nonfunctional PanNEN. In patients who underwent contrast-enhanced harmonic EUS (CH-EUS), lesions were classified into 3 vascular patterns (hypoechoic/isoechoic/hyperechoic), and the presence of "the alveolus nest sign," which we previously reported as a characteristic feature of SPN on CH-EUS, was also assessed.

RESULTS

Conventional EUS findings showed that calcification echoes were significantly more frequent in SPN lesions than in PanNEN lesions (19/29 [66%] vs 21/77 [27%], P = 0.001) as was internal isoechogenicity or hyperechogenicity (10/29 [34%] vs 11/77 [14%], P = 0.029). Contrast-enhanced harmonic EUS findings showed that SPN lesions more frequently had the isoechoic or hypoechoic vascular pattern, and significantly more frequently had the alveolus nest sign (18/25 [72%] vs 4/60 [7%], P < 0.001). In a multivariate analysis, the presence of the alveolus nest sign contributed the most to the SPN diagnosis (odds ratio, 70; 95% confidence interval, 6.2-786).

CONCLUSIONS

Endoscopic ultrasound, particularly the presence of the alveolus nest sign on CH-EUS, is useful for differentiating SPN from PanNEN.

Differentiation of solid-pseudopapillary tumors of the pancreas from pancreatic neuroendocrine tumors by using endoscopic ultrasound

BACKGROUND AND AIM

To differentiate solid-pseudopapillary tumors (SPTs) of the pancreas from pancreatic neuroendocrine tumors (pNETs) by endoscopic ultrasound.

METHODS

We retrospectively reviewed all patients with SPTs and pNETs who underwent endoscopic ultrasound (EUS) from May 2012 to August 2018 at the Fudan University Shanghai Cancer Center. We included patients confirmed pathologically with a surgical biopsy or with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). The demographic data of the patients, characteristics of the lesions and overall survival data of patients with these two diseases were further compared.

RESULTS

A total of 147 pNET patients and 21 SPT patients were included in our study. The mean ages of the patients in the SPT and pNET groups were 35.95years and 54.30years, respectively. There were more females in the SPT group than in the pNET group (71.43% vs. 40.82%). The patients in the pNET group had significantly more lymphatic metastases and visceral organ metastases than the patients in the SPT group. A larger proportion of pNET lesions than SPT lesions had homogeneous echo patterns and were hypervascular. Cystic components and calcification components were more often observed in the SPT lesions than in the pNET lesions. In the multivariate logistic regression analysis, the hypervascularization (OR: 6.528, 95% CI: 1.562-27.285, P=0.010) and cystic component (OR: 0.106, 95% CI: 0.019-0.597, P=0.011) variables resulted in the best discrimination of patients with SPTs from patients with pNETs. Survival among patients with SPTs was higher than that among patients with pNETs at all points in the follow-up period.

CONCLUSIONS

SPTs tended to occur in younger people and were more common in women. Pancreatic neuroendocrine tumors tended to form metastases more often than SPTs. The blood supply and cystic components of the lesions may have novel potential diagnostic utility for differentiating SPTs from pNETs.

Clinical and Pathological Features of Solid Pseudopapillary Neoplasms of the Pancreas: A Nationwide Multicenter Study in Japan

OBJECTIVE

The aim of this study was to evaluate the clinicopathological features of solid pseudopapillary neoplasms (SPNs).

METHODS

In this retrospective study, 288 SPNs were analyzed.

RESULTS

Overall, 214 patients (74%) were female. Distant metastases occurred in 4 patients, and splenic vein tumor thrombus occurred in 1 patient. Although imaging findings showed large (>2.0 cm) SPNs with clear, regular border, and heterogeneous internal structure, small SPNs appeared as almost entirely solid. Surgical resection was performed in 278 cases. The 5-year survival rate was 98.8%. Six patients had tumor recurrence after the initial resection. The detection rate in typical pathological findings was low for small SPNs. Tumor extension to the pancreatic parenchyma was detected in greater than 70% of the cases. Tumor invasion to adjacent organs was detected in 13 cases. One was given a diagnosis of apparent high-grade malignant transformation.

CONCLUSIONS

The proportion of male cases was higher than that in previous studies, and there were statistically significant differences in the onset age and tumor diameter between male and female patients. Therefore, women seemed to have an early occurrence of SPNs, suggesting a difference in the developmental stage between men and women. Images and pathological findings of SPNs varied according to tumor size. Our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.

Diagnosis of a solid pseudopapillary neoplasm using EUS-FNA

A woman in her 50s was found to have a pancreatic mass on abdominal ultrasound. The tumor measured 40 mm in diameter and included a cystic lesion and calcification. In this case, we suspected a diagnosis of solid pseudopapillary neoplasm (SPN) due to the findings observed on various images. However, we were unable to exclude the possibility that the lesion was a neuroendocrine tumor. Therefore, we performed endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA). In addition, in order to confirm the diagnosis of SPN, we performed minimized resection (segmental pancreatectomy). Obtaining a definitive preoperative diagnosis of SPN using EUS-FNA can guide the surgical approach.