Recurrence of Solid Pseudopapillary Neoplasms of the Pancreas: Results of a Nationwide Study of Risk Factors and Treatment Modalities

Solid pseudopapillary tumor of the pancreas: A systematic review of clinical, surgical and oncological characteristics of 1384 patients underwent pancreatic surgery

BACKGROUND

Pancreatic solid pseudopapillary tumors (SPTs) are rare clinical entity, with low malignancy and still unclear pathogenesis. They account for less than 2% of exocrine pancreatic neoplasms. This study aimed to perform a systematic review of the main clinical, surgical and oncological characteristics of pancreatic SPTs.

DATA SOURCES

MEDLINE/PubMed, Web of Science and Scopus databases were systematically searched for the main clinical, surgical and oncological characteristics of pancreatic SPTs up to April 2021, in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) standards. Primary endpoints were to analyze treatments and oncological outcomes.

RESULTS

A total of 823 studies were recorded, 86 studies underwent full-text reviews and 28 met inclusion criteria. Overall, 1384 patients underwent pancreatic surgery. Mean age was 30 years and 1181 patients (85.3%) were female. The most common clinical presentation was non-specific abdominal pain (52.6% of cases). Mean overall survival was 98.1%. Mean recurrence rate was 2.8%. Mean follow-up was 4.2 years.

CONCLUSIONS

Pancreatic SPTs are rare, and predominantly affect young women with unclear pathogenesis. Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

Unraveling the enigma: A comprehensive review of solid pseudopapillary tumor of the pancreas

Solid pseudopapillary tumor of the pancreas (SPTP) is a rare neoplasm predominantly observed in young females. Pathologically, CTNNB1 mutations, β-catenin nuclear accumulation, and subsequent Wnt-signaling pathway activation are the leading molecular features. Accurate preoperative diagnosis often relies on imaging techniques and endoscopic biopsies. Surgical resection remains the mainstay treatment. Risk models, such as the Fudan Prognostic Index, show promise as predictive tools for assessing the prognosis of SPTP. Establishing three types of metachronous liver metastasis can be beneficial in tailoring individualized treatment and follow-up strategies. Despite advancements, challenges persist in understanding its etiology, establishing standardized treatments for unresectable or metastatic diseases, and developing a widely recognized grading system. This comprehensive review aims to elucidate the enigma by consolidating current knowledge on the epidemiology, clinical presentation, pathology, molecular characteristics, diagnostic methods, treatment options, and prognostic factors.

Solid pseudopapillary neoplasms of the pancreas in childhood and adolescence-an analysis of the German Registry for Rare Pediatric Tumors (STEP)

Solid pseudopapillary neoplasms (SPNs) are the most common entity among pediatric pancreatic tumors. Still, these are rare tumors with an annual incidence of 0.1-0.2/1,000,000, and little is known about their optimal treatment. This analysis aimed to increase knowledge about the occurrence and treatment strategies of SPN in childhood. Data regarding diagnostics, treatment, and outcome of children aged 0-18 years with SPN recorded in the German Registry for Rare Pediatric Tumors (STEP) were analyzed. Thirty-eight patients were identified with a median age of 14.5 years at diagnosis (range: 8-18) and a female preponderance (81.6%). The most frequent location of the tumor was the pancreatic tail. In histopathological and immunohistochemical examination, pseudopapillary, solid, and cystic lesions as well as expression of beta-catenin, progesterone receptors, and cyclin D1 were the most common findings. All patients underwent surgical resection. Most patients underwent open resection, predominantly tail resection for tumors in the tail region and pylorus-preserving pancreaticoduodenectomy for tumors in the head region. The main postoperative sequela was exogenous pancreatic insufficiency (23.7%), especially with SPN in the pancreatic head. No recurrence occurred during follow-up, although two patients underwent resection with microscopic residue.

CONCLUSION

SPN of the pancreas in childhood are low-grade malignancies with usually favorable treatment outcomes. However, therapy can lead to relevant long-term sequelae. To prevent recurrence, complete surgical resection is recommended, sparing as much healthy pancreatic tissue as possible. Interdisciplinary collaboration between specialists is essential to optimize treatment. Molecular genetic analysis of these tumors could improve understanding of their genesis.

WHAT IS KNOWN

• Solid pseudopapillary neoplasms (SPNs) of the pancreas are very rare tumors in childhood. • Little is known about tumorigenesis, and there are no specific guidelines for treatment and follow-up in pediatric patients.

WHAT IS NEW

• Characteristics, treatment, and outcome were comprehensively assessed in a large cohort of pediatric patients with SPN. • We propose recommendations for diagnosis, treatment, and follow-up of children with SPN, based on our analysis and considering published experience.

Long-term Survival, Quality of Life, and Molecular Features of the Patients With Solid Pseudopapillary Neoplasm of the Pancreas: A Retrospective Study of 454 Cases

OBJECTIVE

To present comprehensive information on the clinicopathological, molecular, survival characteristics, and quality of life (QOL) after surgery for solid pseudopapillary neoplasm (SPN) of the pancreas in a large cohort after long-term follow-up.

BACKGROUND

SPN is a rare tumor with an uncertain malignant potential, and solid information on long-term prognosis and QOL remains limited.

METHODS

All hospitalized patients with SPNs who underwent surgery between 2001 and 2021 at the Peking Union Medical College Hospital were retrospectively reviewed. The clinicopathological characteristics of the patients were retrieved. A cross-sectional telephone questionnaire was administered to inquire about the QOL. Molecular analyses were performed using whole-exome sequencing.

RESULTS

Exactly 454 patients with SPN were enrolled, of whom 18.5% were males and 81.5% were females. The mean patient age was 31 ± 12 years. In total, 61.3% of the patients had no symptoms. The size of the tumors was 5.38 ± 3.70 cm; 83.4% were solid cystic tumors, and 40.1% had calcifications. The proportions of local resection, distal pancreatectomy with or without splenectomy, and pancreaticoduodenectomy with or without pylorus preservation were 29.7%, 28.9% or 22.9%, and 11% or 6.8%, respectively. Over the years, there has been a significant shift from open to minimally invasive surgery. Among all surgical procedures, pylorus-preserving pancreaticoduodenectomy (PPPD) had the highest incidence of grade 2 to 4 complications (up to 32.3%), compared with 6.7% in distal pancreatectomy ( P < 0.001). Regarding histopathology, tissue invasion, perineural invasion, cancerous microvascular emboli, lymph node metastasis, and distant metastasis were present in 16.5%, 2.2%, 0.7%, 2.0%, and 3.1% of patients, respectively. Sixty patients were lost to follow-up. Sixteen of the 390 patients who underwent resection (4.1%) experienced local recurrence or distant metastasis after surgery. In total, 361 patients responded to the telephone survey. Nearly 80% of patients claimed their QOL was not significantly affected after surgery; however, the remaining 20% complained of lower QOL during 3 to 6 years of follow-up after surgery. No clinicopathological factor could reliably predict clinical recurrence or metastasis after resection. A total of 28 driver genes were detected with mutations in at least 2 tumor samples and the top 3 frequently mutated genes were CTNNB1 , ATRNL1 , and MUC16 .

CONCLUSIONS

This study presented the largest cohort of patients with SPN after surgery from a single center and reported the QOL of these patients. SPN is associated with extremely favorable long-term survival, even in patients with metastasis, and most patients have a good QOL after surgery.

Pancreatic Incidentaloma

Pancreatic incidentalomas (PIs) represent a clinical entity increasingly recognized due to advances in and easier access to imaging techniques. By definition, PIs should be detected during abdominal imaging performed for indications other than a pancreatic disease. They range from small cysts to invasive cancer. The incidental diagnosis of pancreatic cancer can contribute to early diagnosis and treatment. On the other hand, inadequate management of PIs may result in overtreatment and unneeded morbidity. Therefore, there is a strong need to evaluate the nature and clinical features of individual PIs. In this review, we summarize the major characteristics related to PIs and present suggestions for their management.

Clinicopathological factors associated with recurrence in patients undergoing resection of pancreatic solid pseudopapillary neoplasm

PURPOSE

Solid pseudopapillary neoplasm (SPN) is an uncommon pathology with a low-grade malignancy. Surgery is the milestone treatment. Nevertheless, despite appropriate management, some patients present recurrence. Risk factors associated with recurrence are unclear. The objective was to identify the clinicopathological factors associated with recurrence in patients with SPN treated with pancreatic resection.

METHODS

Medical records of patients treated with pancreatic resection during 2006-2020 were evaluated. Patients with histological diagnosis of SPN were included. Survival analysis was performed to identify the clinicopathological factors related to recurrence.

RESULTS

Seventy-four patients were diagnosed with SPN; 70 (94.6%) patients were female, and the median age was 20 years old. The median tumor diameter was 7.9 cm. Multivisceral resection was performed in 9 (12.2%) patients. Four (5.4%) patients presented lymph node metastasis.R0 resection was achieved in all cases. Six (8%) patients presented recurrence and the liver was the most frequent recurrence site (n = 5).After a median follow-up of 40.2 months, 9 (12%) patients died. Five (6.8%) patients died of disease progression. The 1-3- and 5-year overall survival (OS) was 97.1%, 90.2% and 79.9%, respectively. The 1-3-and-5-year recurrence-free survival (RFS) was 98.4%, 89.9% and 87%, respectively. In the univariate Cox-regression analysis, age ≥ 28 years(HR = 8.61, 95% CI 1.1-73.8),tumor diameter ≥ 10 cm(HR = 9.3, 95% CI 1.12-79.6),invasion of adjacent organs (HR = 7.45, 95% CI 1.5-36.9), lymph node metastasis (pN +) (HR = 16.8, 95% CI 2.96-94.9) and, AJCC Stage III (HR = 10.1, 95% CI 1.2-90.9) were identified as predictors for recurrence.

CONCLUSIONS

SPN is more frequently diagnosed in young women with a good overall prognosis after an R0 surgical resection even with disease recurrence. Age ≥ 28 years, larger tumors ≥ 10 cm, invasion of adjacent organs, lymph node metastasis(pN +) and, AJCC Stage III were predictors factors of recurrence in resected SPN.

Molecular Alterations in Solid Pseudopapillary Neoplasm of the Pancreas: The Achilles Heel in Conquering Pancreatic Tumorigenesis

Solid pseudopapillary neoplasms of the pancreas are overwhelmingly benign tumors predominately observed in women in the third decade of life. However, their malignant potential, based on local recurrences and metastases, has brought into question the available evidence on their biological behavior. Solid pseudopapillary neoplasms have distanced themselves from other pancreatic tumors with varying morphological appearance, immune profile, and histogenesis. In review of the literature, PubMed was queried using search strings, including "solid pseudopapillary neoplasm" and "molecular," and "immunohistochemistry." Alternative searches were also conducted given the variability in tumor name, including "solid pseudopapillary tumor" and "Frantz tumor." This article provides an in-depth review into the molecular pathways that contribute to the pathogenesis of solid pseudopapillary neoplasms. It also discusses the implications of existing molecular pathways toward tumor aggressiveness and recurrence potential.

Robotic Surgery in Pediatric Oncology: Lessons Learned from the First 100 Tumors-A Nationwide Experience

BACKGROUND

While robotics has become commonplace in adult oncology, it remains rare in pediatric oncology due to the rarity of childhood cancers. We present the results of a large nationwide experience with robotic oncology, with the aim of providing practical and feasible guidelines for child selection.

METHODS

This was a prospective analysis performed over a period of 4 years. Treatment was delivered according to the Société Internationale d'Oncologie Pédiatrique/International Society of Paediatric Oncology Europe Neuroblastoma Group (SIOP/SIOPEN) protocols. Indications were approved by a certified tumor board.

RESULTS

Overall, 100 tumors were resected during 93 procedures (abdomen, 67%; thorax, 17%; pelvis, 10%; retroperitoneum, 6%) in 89 children (56 girls). The median age at surgery was 8.2 years (range 3.6-13); 19 children (21%) harbored germinal genetic alterations predisposing to cancer. No intraoperative tumor ruptures occurred. Seven conversions (8%) to an open approach were performed. Neuroblastic tumors (n = 31) comprised the main group (18 neuroblastomas, 4 ganglioneuroblastomas, 9 ganglioneuromas) and renal tumors comprised the second largest group (n = 24, including 20 Wilms' tumors). The remaining 45 tumors included neuroendocrine (n = 12), adrenal (n = 9), germ-cell (n = 7), pancreatic (n = 4), thymic (n = 4), inflammatory myofibroblastic (n = 4), and different rare tumors (n = 5). Overall, 51 tumors were malignant, 2 were borderline, and 47 were benign. The median hospital stay was 3 days (2-4), and five postoperative complications occurred within the first 30 days. During a median follow-up of 2.4 years, one child (Wilms' tumor) presented with pleural recurrence. One girl with Wilms' tumor died of central nervous system metastasis.

CONCLUSIONS

Robotic surgery for pediatric tumors is a safe option in highly selected cases. Indications should be discussed by tumor boards to avoid widespread and uncontrolled application.

Pancreatic Solid Pseudopapillary Neoplasm: Key Pathologic and Genetic Features

CONTEXT.—

Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor generally associated with a good prognosis. Solid pseudopapillary neoplasms show peculiar morphologic features, but sometimes the differential diagnosis with other pancreatic neoplasms (ie, pancreatic neuroendocrine tumors) can be a challenging task, especially in cytologic or biopsy specimens. In these cases immunohistochemistry is a useful tool, but the diagnostic utility of several proposed immunohistochemical markers is questionable. In recent years, despite several attempts to characterize the pathogenetic, molecular, and prognostic features of solid pseudopapillary neoplasms, they still remain unclear.

OBJECTIVE.—

To give the reader a comprehensive update on this entity.

DATA SOURCES.—

The PubMed database (US National Library of Medicine) was searched using the following string: pseudopapillary tumor [AND/OR] neoplasm [AND/OR] pancreas. All articles written in English were included. In addition, because a heterogeneous terminology has been used in the past to define solid pseudopapillary neoplasms, the reference lists of each paper selected in the PubMed database were also reviewed.

CONCLUSIONS.—

This review gives a comprehensive update on the pathologic, clinical, and molecular features of solid pseudopapillary neoplasms, particularly addressing issues and challenges related to diagnosis. In addition, we have tried to correlate the molecular alterations with the morphologic and clinical features.

Clinical Pattern of Preoperative Positron Emission Tomography/Computed Tomography (PET/CT) Can Predict the Aggressive Behavior of Resected Solid Pseudopapillary Neoplasm of the Pancreas

Simple Summary

Predicting the aggressiveness of solid pseudopapillary neoplasms (SPNs) remains a worthwhile goal. The present study aimed to identify perioperative factors that can predict patients who will develop clinically aggressive SPN. A total of 98 patients diagnosed with SPNs were analyzed retrospectively. We found that age (≥40 years; p = 0.039), symptomatic presentation (p = 0.001), tumor size (>10 cm; p < 0.001), positron emission tomography/computed tomography (PET/CT) classification (Type III; p < 0.001), and lymphovascular invasion (p = 0.003) were significantly correlated with aggressive behavior of SPNs. Among these, age ≥40 years, PET/CT Type III configuration, and lymphovascular invasion were independent factors associated with an aggressive SPN. This information can help clinicians develop individualized management and surveillance plans to manage patients more competently.

Abstract

Predicting the aggressiveness of solid pseudopapillary neoplasms (SPNs) remains an important goal. The present study aimed to identify perioperative factors that can predict patients who will develop clinically aggressive SPN. Records of individuals with pathologically confirmed SPN from 2006 to 2017 were obtained from the patient registry database of Yonsei University, Severance Hospital. For this study, aggressive behavior was defined as SPN that had recurred, metastasized, or involved adjacent organs. A total of 98 patients diagnosed with SPNs were analyzed retrospectively. Of these, 10 were reported to have SPNs with aggressive characteristics. We found that age (≥40 years; p = 0.039), symptomatic presentation (p = 0.001), tumor size (>10 cm; p < 0.001), positron emission tomography/computed tomography (PET/CT) classification (p < 0.001), and lymphovascular invasion (p = 0.003) were significantly correlated with aggressive behavior of SPNs. Multivariate analysis showed that PET/CT configuration (p = 0.002) (exp(β)111.353 (95% confidence interval (CI): 5.960–2081), age ≥40 years (p = 0.015) (exp(β) 23.242 (95% CI: 1.854–291.4)), and lymphovascular invasion (p = 0.021) (exp(β) 22.511 (95% CI: 1.595–317.6)) were the only independent factors associated with aggressive SPN. Our data suggest that age ≥40 years, PET/CT Type III configuration, and lymphovascular invasion are independent factors associated with aggressive SPN. This information can help clinicians develop individualized management and surveillance plans to manage patients more effectively.

Solid-Pseudopapillary Neoplasm of the Pancreas: A 63-Case Analysis of Clinicopathologic and Immunohistochemical Features and Risk Factors of Malignancy

Purpose

Solid-pseudopapillary neoplasm (SPN) of the pancreas, a rare tumor, has low malignant potential. However, some patients develop metastasis and recurrence after resection, with aggressive biological behaviors. This study aimed to explore the features and risk factors associated with the aggressive biological behaviors of SPNs.

Patients and Methods

We retrospectively analyzed the clinicopathological and long-term follow-up data of 63 patients diagnosed with SPN at the First Affiliated Hospital of Bengbu Medical College between January 2007 and February 2019.

Results

Sixty-three patients presented atypical clinical symptoms. The median tumor size was 7.0 cm (range, 2.4–17 cm), and imaging features were solid and cystic or solid tumors with uneven density. Frequent and diffuse nuclear LEF1 protein expression (94.2%) was observed with LEF1 having a higher sensitivity and specificity. Overall survival significantly correlated with tumor size, Ki-67 index, and lymph node metastasis (P < 0.05).

Conclusion

SPN is a rare low-grade malignancy with a specific pseudopapillary structure. LEF1 is an effective biomarker of SPNs. Although SPNs generally display indolent biological behavior, a large tumor size, high proliferation index, and lymph node metastasis may be risk factors for the aggressive behavior and poor prognosis of SPN.

Clinical characteristics, treatment outcomes, and occurrence of diabetes mellitus after pancreatic resection of solid pseudopapillary tumor in children and adolescents: A single institution experience with 51 cases

BACKGROUND

Solid pseudopapillary tumors (SPTs) are rare, but they comprise the majority of pediatric pancreatic neoplasms. However, studies on these conditions in pediatric patients are lacking. The aim of this study was to investigate the clinical characteristics and treatment outcomes in children and adolescents with SPTs.

METHODS

This retrospective study included 51 patients with SPTs who had undergone pancreatic tumor resection before the age of 19 years at Samsung Medical Center in Korea (from November 1994 to August 2020). We investigated the postoperative outcomes.

RESULTS

Of the 51 patients with SPTs (female, 88.2%), the median age at diagnosis was 14 years (range, 8-19). The most common symptom was abdominal pain (60.8%), and 14 patients (27.5%) were asymptomatic. The median maximal tumor diameter was 7 cm (range, 1.4-14), and the pancreatic body and/or tail were involved in 68.6% of patients. The short-term complication rate was 21.5%, and the recurrence rate was 5.9%. New-onset diabetes mellitus (NODM) occurred in four patients.

CONCLUSIONS

The ideal treatment for SPTs is complete resection of the tumor; however, long-term postoperative complications including NODM should be monitored carefully, particularly in children and adolescents.

Clinicopathological and immunohistochemical study of 29 cases of solid-pseudopapillary neoplasms of the pancreas in patients under 20 years of age along with detailed review of literature

Background

Pancreatic Solid Pseudopapillary Neoplasms (SPNs) are rare low-grade malignant tumors with a marked preponderance for young females. Objective was to describe the morphology, differential diagnosis, and prognosis of SPNs in patients under 20 years of age and present a detailed review of literature.

Methods

A total of 29 cases in patients under 20 years of age reported as SPN during the period January 2014 to December 2019, were included in the study. These included 19 resection specimens, 4 incision biopsies and 6 cases received as blocks for second opinion. Hematoxylin and eosin (H&E) slides as well as immunohistochemistry (IHC) slides of all cases were retrieved and reviewed by the authors. TFE3 and Progesterone Receptor were performed retrospectively.

Results

Twenty-eight of the 29 patients were females. Ages of patients ranged from 12 to 19 years. Nineteen cases were resections. Tail was the commonest location. Mean tumor size was 9.5 cm. In 89.5% cases, tumor was confined to the pancreas. In 2 cases, distant metastasis was present. In 2 cases, extension beyond pancreas was seen. Solid and pseudopapillary areas were seen in all cases while other features were variable. Beta catenin and Cyclin D1 were positive in most cases while TFE3 was positive in 57% cases. Progesterone Receptor (PR) was positive in all 13 cases in which it was performed. Follow up was available in 14 patients. Follow up period ranged from 3 to 70 months. Twelve were alive and well without recurrence or metastasis while 2 were alive with recurrence and metastasis to liver and omentum respectively.

Conclusions

Although many studies on SPNs have been published, surgeons, oncologists and even pathologists in this part of the world are often not aware of these rare tumors leading to inaccuracies and delays in diagnosis. In addition, this paper focusses on the interesting observation that the majority of SPNs diagnosed in our department during study period occurred in patients under 20 years of age (29 versus 21 in patients over 20). However, clinico-epidemiological, morphologic and prognostic features were similar in both age groups. Possibility of SPNs should always be considered in case of pancreatic neoplasms occurring in patients under 20 years of age as well. We believe that this is a very interesting and helpful study for the clinicians as well as the pathologists.

A systematic review and meta-analysis of predictors of recurrence in patients with Solid Pseudopapillary Tumors of the Pancreas

BACKGROUND

The recurrence rates and predictors of recurrence in patients with Solid Pseudopapillary tumors (SPT) are unclear, which makes it challenging to determine the duration of follow-up. The aim of the current study was to perform a systematic review and meta-analysis to determine the recurrence rates and pathologic factors associated with recurrence in patients with SPT.

METHODS

A PubMed, Scopus, and Web of Science search was conducted to identify studies of SPT published during the last 15 years: (09/2002-09/2017). Studies reporting on patients with SPT and follow-up of >5 years were included. The search strategy was conducted per 2009 PRISMA guidelines.

RESULTS

A total of 103 studies reporting on 2599 non-metastatic SPT patients were identified. Sixty-nine patients (2.6%) developed recurrence during follow-up. Pooled estimates from studies with a sample size >20 (N = 33) noted an overall recurrence rate of 2% (95% CI 1-2%). Male gender (OR 1.960), positive lymph nodes (OR 11.9), R1 margins (OR 11.1), and LVI (OR 5.5), were associated with a significantly (all p < 0.05) increased risk of recurrence.

CONCLUSION

Current meta-analysis suggests that only 2% of patients with SPT experience recurrence after resection. These data will guide the treating physicians and patients regarding recurrence rates and help identify patients at increased risk of recurrence during follow-up.

Laparoscopic Distal Pancreatectomy of a Solid Pseudopapillary Tumor (SPT) Achieves Long-Term Oncologic Safety and Multiorgan Preservation

The oncological safety of a laparoscopic approach for solid pseudopapillary tumors (SPTs) of the pancreas remains a matter of debate. We present the long-term follow-up of an adolescent girl with an SPT in the pancreatic tail. A multimodality workup including magnetic resonance imaging (MRI) revealed a complex, spherical mass of 4.4 cm × 3.6 cm × 4 cm most likely located in the pancreatic tail. All routine laboratory investigations and tumor markers were within normal limits (alpha fetoprotein [AFP], cancer antigen 125 [CA125], CA 19-9, carcinoembryonic antigen [CEA], adrenocorticotropic hormone [ACTH]). Diagnostic laparoscopy was performed to verify the origin of the tumor in the pancreatic tail. In a three-port technique the tumor was mobilized of the splenic vessels until a distal pancreatectomy could be completed. Histopathological examination confirmed the complete resection of a low-grade malignant SPT. The postoperative course was unremarkable. Regular pediatric oncological follow-up examinations for 3 years, including MRI every 6 months, ruled out recurrence and confirmed preservation of splenic and pancreatic functions. While data about the technical feasibility of a laparoscopic approach to pancreatic SPT are already available, this pediatric case report adds a long-term oncological and functional success to the available literature.

Outcome and prognosis after pancreatectomy in patients with solid pseudopapillary neoplasms

BACKGROUND

Solid pseudopapillary neoplasms (SPN) are rare and represent approximately 4% of all cystic pancreatic tumors. The prognosis is excellent, although 10-15% of SPN patients show metastasis at the time of surgery or tumor recurrence during follow-up after pancreatectomy. Aim of the study was to analyze surgical management, risk factors for malignancy as well as long-term outcome and prognosis of this distinct tumor entity.

METHOD

All patients with pancreatic resection for SPN between 10/2001 and 07/2018 in the authors' institution were identified from a prospective database. Clinicopathologic details, perioperative data and long-term follow-up results were retrospectively analyzed.

RESULTS

Fifty-two patients were identified, 44 (85%) of them were female and the median age was 29 years (IQR 9-71). Seven (13%) patients showed a malignant behaviour of SPN with N1 (n = 2) or M1 (n = 1) disease at resection; 5 patients developed tumor recurrence, after a median of 21 months. During follow-up time (median 54 months) all patients were alive, the 5- and 10-year rates for disease-free survival were 89.0% and 81.6%, respectively. Significant risk factors for recurrence were age <18 years (p = 0.0087) and parenchyma-preserving surgical approaches (p = 0.0006). The postoperative long-term outcome showed ECOG = 0-1 in all patients, with resection related exocrine insufficiency in 20 (41%) and diabetes mellitus in 2 (4%) patients.

CONCLUSIONS

Age < 18 years is a significant risk factor for malignancy in SPN, and parenchyma preserving resections harbor a significant risk for tumor recurrence. As recurrence may occur late, a systematic life-long follow-up should be performed.

Solid-pseudopapillary Neoplasms of the Pancreas is still an Enigma: a Clinicopathological Review

The solid-pseudopapillary neoplasm of the pancreas is a rare but enigmatic entity occurring mainly in young women. Since the first description by V. Frantz in 1959 the terminology of this tumor has continuously changed but it has remained simply descriptive, because the exact histogenesis is still obscure. Although in majority of cases the survival is excellent, nevertheless, the expected prognosis is not exactly predictable. In this review the authors aim to summarize its clinico-pathological features, the expected biological behavior, the molecular alterations, the immune phenotype and discuss the putative histogenesis. From diagnostic point of view, the salient histological characteristic findings are analyzed that would help to differentiate it from other, look-alike pancreatic tumors, and suggestions are made about the desirable content of the histological report.

Outcome after surgery for solid pseudopapillary pancreatic tumors in children: Report from the TREP project-Italian Rare Tumors Study Group

BACKGROUND

Solid pseudopapillary pancreatic tumors (SPPT) are an extremely rare entity in pediatric patients. Even if the role of radical surgical resection as primary treatment is well established, data about follow-up after pancreatic resection in children are scant.

METHODS

A retrospective review of data from the Italian Pediatric Rare Tumor Registry (TREP) was performed. Short-term (<30 days) and long-term complications of different surgical resections, as well as long-term follow-up were evaluated.

RESULTS

From January 2000 to present, 43 patients (male:female = 8:35) were enrolled. The median age at diagnosis was 13.2 years (range, 7-18). Nine children had an incidental diagnosis, whereas 26 complained of abdominal pain and 4 of palpable mass. Tumors arose either from the head of pancreas (n = 14) or from body/tail (n = 29): only one patient presented with metastatic disease. Resection was complete in all patients (cephalic duodenopancreatectomy vs distal resection). At follow-up (median, 8.4 years; range, 0-17 years), one recurrence occurred in a patient with intraoperative rupture. All patients are alive. Three pancreatic fistulas occurred in the body/tail group, whereas four complications occurred in the head group (one ileal ischemia, two stenosis of the pancreatic duct, and one chylous fistula).

CONCLUSION

Surgery is the best therapeutic option for these tumors; hence, complete resection is mandatory. Extensive resections, including cephalic duodenopancreatectomy, are safe when performed in specialized centers. Long-term follow-up should be aimed to detect tumor recurrence and to evaluate residual pancreatic function.

Solid pseudopapillary neoplasm of the pancreas: Clinical-pathological features and management, a single-center experience

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of low malignancy that occurs most often in females. The study describes the clinicopathologic characteristics of the tumor and common differential diagnoses. Data were collected from a prospectively maintained database. Of 1661 patients operated for pancreatic tumors between January 2001 and September 2018, 15 patients were recorded. Patients included 12 females and 3 males, median age 40 (range 10 -87) years. Computed tomography or magnetic resonance imaging was diagnostic in eight patients and a preoperative biopsy in eight out of 10 patients. Median tumor size was 5 cm (range 2 -16 cm), 12 tumors were in the head, six in the body, and three in the tail of the gland. All patients except one had radical resection including one with hepatic and lymph node metastases, no patient underwent oncologic treatment. All patients are alive from 17.5 to 209.4 months postoperatively and without recurrence. Radical operation is usually curative and should also be offered to patients with metastases or recurrence as oncologic treatment has limited effect.

Solid pseudopapillary and malignant pancreatic tumors in childhood: A systematic review and evidence quality assessment

A systematic review of 32 studies reporting on 489 children with pancreatic tumors was performed. The most prevalent histologic subtype was solid pseudopapillary tumor (SPT) (61.3%). Pancreaticoduodenectomy was the most commonly performed operation (48%). Neoadjuvant chemo/radiotherapy was utilized in 3.9, 36.2, 25, and 27.8% of patients with SPTs, pancreatoblastomas (PBLs), neuroendocrine tumors, and exocrine carcinomas, respectively. Adjuvant chemotherapy (75.6%) and radiation (34%) were most commonly utilized in PBLs. All-cause mortality was highest in exocrine carcinomas (50%). Overall, 98.8% of patients with SPTs survived. PBL exhibited the highest recurrence rate (14.7%) within a mean of 23.5 months.

Prediction of malignancy and adverse outcome of solid pseudopapillary tumor of the pancreas

Since solid pseudopapillary tumor of the pancreas (SPTP) was officially classified by the World Health Organization in 1996, SPTP has recently received special attention in the literature. Studies have shown that SPTP is a heterogeneous tumor, with a small percentage of patients harboring aggressive behaviors. However, criteria for malignancy grade in SPTP have not been well established. The prognosis of SPTP is generally good, with cases having a chance for long-term survival even with recurrence and/or metastasis after surgical resection. The current American Joint Committee on Cancer/Union for International Cancer Control tumor, node, metastasis staging system is not specific to SPTP. The lack of a predictive staging classification that accurately describes the heterogeneity of this disease hinders meaningful research into optimal individualized therapy. Here we summarize and discuss the associated factors proposed for appraisal of the malignant potential and adverse outcome of SPTP.

Recurrent Solid Pseudopapillary Neoplasm of Pancreas: Case Report and Review of Literature

Background: Solid pseudopapillary neoplasm of pancreas is a rare tumor with a low potential for metastasis and recurrence. Long-term outcomes after surgical resection are excellent and recurrences after an R0 resection are extremely rare.

Case Presentation: We present an unusual case of a 42-year-old man who had a recurrence of his solid pseudopapillary tumor 4 years after undergoing a distal pancreatectomy and splenectomy and then again a year after his reresection.

Conclusions: The lack of histological features deemed to be suggestive of a malignant variant and the aggressive clinical course seen in this case is remarkable. It underscores the fact that despite the low incidence, recurrences of solid pseudopapillary neoplasms of the pancreas do occur and it can be very difficult to predict malignant potential based on radiological or histopathological features.

European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN.

Risk Factors of the Recurrences of Pancreatic Solid Pseudopapillary Tumors: A Systematic Review and Meta-analysis

Background: Pancreatic solid pseudopapillary tumors (SPTs) are rare neoplasms with low-grade malignancy. The main treatment for them is surgical resection. However, some SPTs relapse after resection. The risk factors associated with the recurrences of resected SPTs remain controversial to date. We performed a systematic review and meta-analysis to identify the risk factors of the recurrences of pancreatic SPTs.

Materials and Methods: We searched PubMed, EMBASE, and the Cochrane Library from their inception to December 2017. Studies that focused on the risk factors of postoperative relapses of pancreatic SPTs were enrolled. Combined ORs with 95% CIs were calculated to evaluate the effects of relevant factors investigated in eligible studies. Heterogeneity among combined results was assessed by Cochran's Q test and by the degree of inconsistency (I²). Statistical analyses were performed by Review Manager (version 5.3) using random effects models.

Results: We included 10 studies, which enrolled 1091 patients. The pooled results suggested that patients with larger tumors (diameter > 5cm), lymphovascular invasion, lymph node metastasis, synchronous metastasis and positive margin were prone to suffer from the recurrences of SPTs. In addition, some factors like gender, location of tumors, perineural invasion, calcification and capsular invasion did not show any correlation with the relapses of resected SPTs.

Conclusion: Factors including a larger tumor size (diameter > 5cm), lymphovascular invasion, lymph node metastasis, synchronous metastasis and positive margin may increase the risk of recurrences of resected pancreatic SPTs. All SPTs should be excised and patients with high-risk features should undergo a long-term follow-up.

One Hundred Twenty-One Resected Solid Pseudopapillary Tumors of the Pancreas: An 8-Year Single-Institution Experience at Zhongshan Hospital, Shanghai, China

OBJECTIVES

The aims of this study were to introduce our experience with treating patients with pancreatic solid pseudopapillary tumors (SPTs) and to investigate the clinical risk factors for recurrence of SPTs because no consensus has been established to date.

METHODS

One hundred twenty-one patients underwent surgical resection from January 2008 to December 2015 in our institution. Clinical data were collected from the standardized reports.

RESULTS

Of the 121 patients, 93 (76.9%) were women, 28 (23.1%) were men, and the mean age at diagnosis was 33.7 years (range, 11-68 years). Sixty patients were subjected to short-term complications, and 8 patients experienced long-term complications, some of whom may require surgery. The tumor located in the distal pancreas (P = 0.02), and a Ki-67 index value > 1.5 (P = 0.01) indicated malignancy according to the World Health Organization 2000 classification. One hundred three patients responded to follow-up, and 3 cases (2.9%) were subject to liver metastases. Recurrence was more frequently observed in tumors classified as high-grade malignancies according to the World Health Organization 2010 classification (P = 0.013), synchronous metastases (P < 0.001), peripancreatic fat infiltration (P = 0.018), and lymphovascular invasion (P < 0.001).

CONCLUSIONS

Evaluating the risk of the recurrence of SPTs still requires systematic and multicenter trials in the future, even some pathological features showed statistical differences.