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

Solid Pseudopapillary Neoplasms of the Pancreas: Clinicopathologic Analysis and a Predictive Model

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare. They are considered low-grade malignancies, and a small percentage of patients experience recurrence or metastasis. It is critical to investigate associated biological behavior and identify patients at a risk of relapse. This was a retrospective study of 486 patients with SPNs who were diagnosed between 2000 and 2021. Their clinicopathologic features, including 23 parameters and prognoses were analyzed. Six patients (1.2%) presented with synchronous liver metastasis. A total of 21 patients experienced recurrence or metastasis postoperatively. The overall and disease-specific survival rates were 99.8% and 100%, respectively. The 5- and 10-year relapse-free survival (RFS) rates were 97.4% and 90.2%, respectively. Tumor size, lymphovascular invasion, and the Ki-67 index were independent predictors of relapse. Furthermore, a Peking Union Medical College Hospital-SPN risk model was built to evaluate the risk of relapse and compared it with the American Joint Committee on Cancer tumor staging system (eighth edition, 2017). Risk factors included 3 parameters: tumor size (>9 cm), lymphovascular invasion status (presence), and Ki-67 index (>1%). Risk grades were available for 345 patients, who were divided into 2 groups: (1) low risk (n = 124) and (2) high risk (n = 221). The group with no risk factors was designated as low risk and had a 10-year RFS of 100%. The group associated with 1 to 3 factors was designated as high risk, with a 10-year RFS of 75.3%. Receiver operating characteristic curves were generated, and the area under the curve was 0.791 for our model and 0.630 for the American Joint Committee on Cancer with respect to the cancer staging system. We validated our model in independent cohorts and demonstrated a sensitivity of 98.3%. In conclusion, SPNs are low-grade malignant neoplasms that rarely metastasize, and the 3 selected pathologic parameters can be used to predict their behavior. A novel Peking Union Medical College Hospital-SPN risk model was proposed for routine application to guide the patient counseling in clinical practice.

Perioperative safety and prognosis following parenchyma-preserving surgery for solid pseudopapillary neoplasm of the pancreas

BACKGROUND/OBJECTIVES

To evaluate perioperative safety and outcome of parenchyma-preserving pancreatectomy and risk factors of metastasis and recurrence for patients with solid pseudopapillary neoplasm (SPN).

METHODS

Demographic data, operative and pathological parameter, follow-up data of patients with SPN undergoing their first operation were collected in our single center from May 2016 to October 2021 and compared between regular pancreatectomy group and parenchyma-preserving surgery group. Risk factors for metastasis and recurrence were investigated.

RESULTS

A total of 194 patients were included, 154 of whom were female and the average age of all patients was 33 years old. Most patients were asymptomatic, with the most common complaint being abdominal pain or discomfort. Of them, 62 patients underwent parenchyma-preserving pancreatectomy including middle segment pancreatectomy and enucleation, and 132 patients underwent regular pancreatectomy including pancreaticoduodenectomy, distal pancreatectomy and total pancreatectomy. Patients in the parenchyma-preserving surgery group had a shorter duration of operation, less intraoperative bleeding, and decreased risk of combined organ removal and blood transfusion, with no statistical significance yet. The two groups exhibited a similar incidence of postoperative complications including grade B and C pancreatic fistula, delayed gastric emptying, postoperative pancreatic hemorrhage, and other complications, as well as radiological intervention, relaparotomy and the length of postoperative hospital stay. There were no perioperative deaths. All the patients, except 18 of those who discontinued follow-up, were alive with a median follow-up time of 31 months. Three patients in the regular pancreatectomy group were observed to have liver metastasis, and no metastasis was observed in the parenchyma-preserving surgery group. Significant risk factors for tumor metastasis and recurrence were tumor size, angioinvasion, and nerve infiltration.

CONCLUSIONS

Parenchyma-preserving surgery did not significantly increase the frequency of perioperative complications or recurrence and might be preferable if comprehensive conditions allow.

Diagnosis and Management of Pancreatic Cysts: A Comprehensive Review of the Literature

The prevalence of pancreatic cysts has been rising due to the widespread use of cross-sectional imaging (CT scan and MRI) of the abdomen. While most pancreatic cysts are benign and do not require treatment or surveillance, a significant minority are premalignant and rarely malignant. The risk stratification of these lesions is not straightforward, and individual risk assessment, cyst size, distribution, and alarming morphologic features (when present) can guide the next steps in management. Neoplastic pancreatic cysts are mucinous or non-mucinous. Endoscopic ultrasound with fine-needle aspiration is often required to classify pancreatic cysts into mucinous and non-mucinous cysts and to assess the malignant potential. Advances in endoscopic techniques (confocal laser endomicroscopy, microforceps biopsy) can provide a definitive diagnosis of pancreatic cysts in some cases; however, the use of these techniques involves a higher risk of adverse events.

Diagnosis and treatment of solid pseudopapillary neoplasm of the pancreas in children: A report of 18 cases

Purpose

To explore the incidence, imaging and treatment of solid pseudopapillary tumor of pancreas in children, and Summarize the experience of treatment.

Methods

The clinical data of 18 children with a solid pseudopapillary tumor of the pancreas treated in our hospital from January 2012 to June 2021 were analyzed retrospectively. The age range was 8-16 years old, the average age was 11.67 years old, and the median age was 11.5 years old, namely, three boys with an average age of 10 years old and 15 girls with an average age of 12 years old. In total, two cases were admitted to the hospital because of trauma, seven cases were found in physical examination, and nine cases were admitted with the abdominal pain as the main complaint. Enhanced CT examination was performed before operation, nuclear magnetic resonance examination and abdominal ultrasound examination were performed in some children, and plain CT scan was performed after operation.

Results

Solid pseudopapillary tumor of the pancreas can occur in all parts of the pancreas, especially in the body and tail of the pancreas. Among the 18 cases, SPN occurred in the head of pancreas in 5 cases (27.78%), the neck of pancreas in 2 cases (11.11%), and the body and tail of pancreas in 11 cases (61.11%). All the 18 children were treated by operation. among them, 4 cases underwent choledochal pancreatico duodenectomy (1 case), 4 cases underwent pancreaticoduodenectomy combined with splenectomy (3 cases), 6 cases underwent spleen-preserving pancreatectomy / tail pancreatectomy (1 case), 3 cases underwent enucleation of pancreatic tumor due to exogenous growth, 1 case underwent laparoscopic partial pancreatectomy and pancreaticoenterostomy. Laparotomy was performed in 12 cases and endoscopic surgery in 6 cases. Postoperative pathology confirmed solid pseudopapillary tumor of the pancreas. None of the patients received radiotherapy and chemotherapy after operation and were followed up for 6 months to 2 years. There was no recurrence, metastasis or pancreatic dysfunction.

Conclusion

Solid pseudopapillary tumor of pancreas in children is a rare, low-grade malignant solid tumor with no specific clinical manifestations and laboratory examinations. Preoperative diagnosis mainly depends on enhanced CT. Surgical resection of tumor is a reliable treatment, and the specific operation is mainly based on the experience of the chief surgeon, the location of the tumor and the invasion of surrounding tissue. At present, there is no evidence of the effectiveness of other treatment options, and surgical resection of the tumor has a good prognosis.

Clinical profile and outcome of solid pseudopapillary neoplasm of the pancreas: A retrospective study on 28 patients

BACKGROUND

Solid pseudopapillary neoplasms (SPN) of the pancreas are rare tumors accounting for 0.9-2.7% of all exocrine pancreatic tumors. Very few studies comprising of more than 10 patients have been published. The aim of the present study is to report on our experience with SPNs over a period of 14 years from a tertiary center of Eastern India.

METHODOLOGY

Data of all patients whose histopathology reports of surgically resected specimen confirmed SPN were retrospectively reviewed in the present study.

RESULTS

Twenty-eight patients had a pathologically confirmed diagnosis of SPN. Twenty-five (89.3%) patients were females with a median age of 26 (15-45) years. Abdominal pain (89.2%) was the most common presenting symptom. Abdominal mass was palpable in 12 (42.8%) patients. The mean size of the tumor was 9.03 cm (range, 4-25 cm). The most common location of the tumor was in the body and tail of pancreas (35.7%). The most commonly performed operation was distal pancreaticosplenectomy (n = 17, 60.7%), followed by Whipple's procedure (n = 8, 28.5%). Thirty postoperative complications developed in 23 (82.1%) patients. The operative mortality was 3.5% (n = 1). The median hospital stay was 10 (5-25) days. Over a median follow-up period of 36 months (range), no patient developed recurrence.

CONCLUSION

Although the size of tumor was quite large at the time of initial presentation, complete surgical resection was possible in all the patients. In experienced hand, surgery can be performed with acceptable perioperative mortality and excellent long-term outcomes.

Prognostic Enigma of Pancreatic Solid Pseudopapillary Neoplasm: A Single-Center Experience of 63 Patients

Background: Studies investigating prognostic factors of solid pseudopapillary neoplasm (SPN) have been published with conflicting findings.

Methods: Retrospective analysis of 63 consecutive cases of SPN in our institution from January 2010 to December 2019 was carried out. The clinicopathological features, treatment practices along with survival associations were collected and analyzed.

Results: Fifteen patients (23.8%) were male, and 48 (76.2%) were female, with a median age of 34.0 ± 14.5 years. The larger tumor size was correlated with the more mixed components (p = 0.000) and the higher Ki-67 index (p = 0.042). No recurrence was found in the nine patients whose tumors fulfilled the WHO criteria for malignancy due to the presence of at least perineural invasion (6.4%), angiovascular invasion (2.3%), and/or adjacent organ invasion (6.4%). Microscopic infiltrative growth was detected in 9 (14.3%) tumors, which was correlated significantly with the WHO criteria (p = 0.002), capsule invasion (p = 0.005), and pancreatic parenchyma invasion (p = 0.001), but not with disease-free survival (p = 0.13). CD99 was found to be positively expressed in 88.9% (40/45) of tumors and more likely to have depressed Ki-67 index (p = 0.016). After a median follow-up of 58 months, only two patients (3.2%) had a recurrence after their first operation outside of our hospital. No patient died due to tumor progression.

Conclusions: Although survival is favorable with aggressive surgery, it is actually difficult to assess the prognostic factors of resected SPNs. Future investigations into the role of clinicopathological evaluation will unveil the prognostic enigma of pancreatic SPN after resection.

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.

Prediction of Recurrence Risk in Solid Pseudopapillary Neoplasm of the Pancreas: Single-Institution Experience

BACKGROUND

Solid pseudopapillary neoplasm (SPN) of the pancreas is a low-grade malignant neoplasm with unpredictable behavior. Factors associated with recurrence were not conclusively identified. The aim of this study is to define the clinicopathological criteria for recurrence risk prediction in SPNs based on the most recent scientific evidence and to present our experience with SPNs.

METHODS

A retrospective review of patients with SPNs operated on in our institution from June 2012 to June 2018 was completed. Patient characteristics and clinical outcomes were analyzed. A detailed literature review was performed to evaluate the factors associated with the recurrence of SPNs.

RESULTS

The cohort consisted of 13 female patients with a median age of 24 years and a mean tumor size of 7.7 cm. Body and tail (53.8%) were the most common location, and distal pancreatectomy with splenectomy was the prevalent surgical procedure. One patient of SPN operated on for local recurrence after 11 years which had high-grade malignant histological features on the previously resected tumor. At a median follow-up of 42 months (range 36 to 108), all patients were disease free and alive. The proposed criteria for predicting recurrence in SPNs include tumor size >8 cm, synchronous metastasis, malignant SPN (according to 2000 or 2010 World Health Organization [WHO] criteria), lymphovascular invasion, pancreatic parenchymal invasion, and high Ki-67 index (>4%). All these are worse prognostic factors and should be considered as high-risk factors for postoperative relapse.

CONCLUSION

The above-mentioned criteria can better predict SPN recurrence. Patients with high-risk features should undergo an extended follow-up.

Development of CT-Based Imaging Signature for Preoperative Prediction of Invasive Behavior in Pancreatic Solid Pseudopapillary Neoplasm

Purpose

It is challenging for traditional CT signs to predict invasiveness of pancreatic solid pseudopapillary neoplasm (pSPN). We aim to develop and evaluate CT-based radiomics signature to preoperatively predict invasive behavior in pSPN.

Methods

Eighty-five patients who had pathologically confirmed pSPN and preoperative contrasted-enhanced CT imaging in our hospital were retrospectively analyzed (invasive: 24; non-invasive: 61). 1316 radiomics features were separately extracted from delineated 2D or 3D ROIs in arterial and venous phases. 200% (SMOTE) was used to generate balanced dataset (invasive: 72, non-invasive: 96) for each phase, which was for feature selection and modeling. The model was internally validated in the original dataset. Inter-observer consistency analysis, spearman correlation, univariate analysis, LASSO regression and backward stepwise logical regression were mainly applied to screen the features, and 6 logistic regression models were established based on multi-phase features from 2D or 3D segmentations. The ROC analysis and Delong's test were mainly used for model assessment and AUC comparison.

Results

It retained 11, 8, 7 and 7 features to construct 3D-arterial, 3D-venous, 2D-arterial and 2D-venous model. Based on 3D ROIs, the arterial model (AUC: 0.914) performed better than venous (AUC: 0.815) and the arterial-venous combined model was slightly improved (AUC: 0.918). Based on 2D ROIs, the arterial model (AUC: 0.814) performed better than venous (AUC:0.768), while the arterial-venous combined model (AUC:0.893) performed better than any single-phase model. In addition, the 3D arterial model performed better than the best combined 2D model. The Delong's test showed that the significant difference of model AUC existed in arterial models in original dataset (p = 0.019) while not in arterial-venous combined model (p=0.49) as comparing 2D and 3D ROIs.

Conclusion

The arterial radiomics model constructed by 3D-ROI feature is potential to predict the invasiveness of pSPN preoperatively.

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.

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.

The Prognostic Factors of Preoperative Prognostic Nutritional Index and Radiological Findings of Solid Pseudopapillary Tumors of Pancreas: A Single-Center Experience of 14 Years

Introduction

Solid pseudopapillary tumors of pancreas (SPTP) is an indolent rare tumor with malignant potential. The prediction of malignancy is an enigma. The aim of this study is to explore the relationship between operative measurements and malignancy prognosis of SPTP patients.

Methods

A cohort of consecutive 102 patients were enrolled in this study. Preoperative measurements and clinical outcomes were analyzed.

Results

Eighteen patients (17.6%) were confirmed as malignant. The malignant SPTP of the optimal cut-off value was 47.9 (p=0.012) for prognostic nutritional index (PNI). The value of PNI≤47.9 and incomplete capsule were significantly correlated with malignancy. Univariate analysis showed that the PNI≤47.9 (p=0.013) and incomplete capsule (p<0.001) were predictors of disease-specific survival (DSS). Multivariate analysis identified the PNI≤47.9 (p=0.036) and incomplete capsule (p=0.023) as the independent prognostic factors of DSS. The new score of 0,1,2 based on PNI and capsule presence stratified the patients into 3 groups. The patients with low PNI and incomplete capsule achieved the worst prognosis.

Conclusion

The combination test of operative PNI and capsule presence would be a reliable indicator of the aggressive natural history of SPTP.

A Review of Clinicopathological Characteristics and Treatment of Solid Pseudopapillary Tumor of the Pancreas with 2450 Cases in Chinese Population

Background

Solid pseudopapillary tumor of the pancreas (SPTP) has been reported as a rare disease with low malignant potential. The aim of this study was to summarize experiences of the diagnosis and treatment for the patients reported in the Chinese population.

Method

2450 SPTP cases reported in English and Chinese literature before Jan 2020 were for our review and analysis retrospectively.

Result

There are 389 male cases and 2061 female cases, and the ratio of male/female was 1 : 5.3. The average age was 29.3 years. The main clinical symptoms were upper abdominal pain and bloating discomfort in 51.6% of the cases and epigastric mass. 38.6% of the tumor was located at the head of the pancreas and 55.4% at the body and tail of the pancreas. The most frequent operative styles were tumor enucleation (38.4%). Pathology showed that the average diameter of the tumor was 8.2 cm and 12.3% of SPTP was malignant. 98.3% of cases had favorable survival.

Conclusions

SPTP is a rare indolent tumor occurring mainly in young women, and the main clinical performances are abdominal mass and abdominal pain; most tumors are distributed at the head and the tail of the pancreas; the prognosis after complete resection is excellent.

Diagnosis and Surgical Treatment and Pathological Findings of Solid Pseudopapillary Tumor of the Pancreas: A Single-Institution Experience

Purpose

To investigate the diagnosis, surgical treatment, and pathology of solid pseudopapillary tumors of the pancreas in our institution.

Patients and Methods

We retrospectively analyzed the demographic details, clinical features, imaging findings, and pathological findings of 87 patients with a confirmed diagnosis of solid pseudopapillary tumors of the pancreas (SPTP) and underwent surgery in Tongji Hospital of Tongji Medical College, over a period of 8 years from 2011 to 2018.

Results

Our study involved a total of 87 patients (16 males and 71 females) with a mean age of 31.3±13.1 years (range: 10–61 years). The main compliant was abdominal pain or discomfort (n=49) and the median tumor size was 58.6±31.7 mm (range: 16–156mm). Tumors were located in the head (27 patients, 31%), the neck (13 patients, 15%), and the body and tail (47 patients, 54%). There were no significant differences between the patients in terms of sex, age, or tumor location. Partial pancreatectomy was performed in 79 patients, enucleation in six patients, and total pancreatectomy in two patients. R0 resection was achieved in 86 patients. The postoperative morbidity was 36.8%, and the main complication was pancreatic fistula. Pathological examination and immunohistochemical markers were used to provide a final diagnosis. The main follow-up period was 46 months (range: 13–97 months). At the end of the follow-up period, 86 patients were alive and had not experienced recurrence; one patient was lost to follow-up.

Conclusion

The accurate diagnosis of SPTP is vital. Our data showed that surgical resection is safe and associated with low morbidity and mortality rates. Pathological findings can play an important role in diagnosis and long-term survival.

Comparison of the clinicopathological features of pancreatic solid pseudopapillary neoplasms between males and females: gender does matter

BACKGROUND

Solid pseudopapillary neoplasms (SPN) of the pancreas are a rare and low-grade malignant entity with a female predominance. However, it also occurs in males, but the rarity and lack of concern makes its clinicopathological features unclarified.

METHODS

The morphological, immunohistochemical, prognostic features and CTNNB1 exon 3 mutation status of SPN were compared semi-quantitively between 9 male and 21 female patients.

RESULTS

SPN in males grew in a distinctive solid pattern, with abundant fibrotic stroma and clear cells. Collagen tended to be the main component of tumor stroma in males, while hyaluronan composed a considerable proportion in females. A much stronger expression of androgen receptor (AR) was found in males, and CD56 and/or synaptophysin (Syn) was expressed frequently in both genders. All patients survived. One male patient had post-operational liver nodules and accepted interventional therapy without biopsy. Mutations of CTNNB1 exon 3 were observed in all cases, distributed at codon 32, 33 and 37 in both genders, as well as 34, 41 and 62 in females.

CONCLUSION

SPN in males presented with significantly different morphological features from that in females, which might be helpful in differential diagnosis, especially when with extensive positivity for CD56 and/or Syn. The stronger expression of AR in males might be a clue to explore the underlying mechanism of the gender difference.

Differentiation of aggressive from non-aggressive pancreatic solid pseudopapillary neoplasms using computed tomography

PURPOSES

Microscopic aggressive behaviors may be related with the prognosis of solid pseudopapillary neoplasms (SPNs). In this study, we investigate computed tomography (CT) features and differential diagnosis of aggressive and non-aggressive SPNs in pancreas.

MATERIALS AND METHODS

122 patients with pathologically proven SPNs in pancreas were included. Patients' age, tumor site, texture, shape, margins, exophytic growth, capsule, calcification, hemorrhage, pancreatic duct dilatation or pancreatic parenchyma atrophy, peripancreatic infiltration or metastases, vascular encasement, and enhancement pattern were assessed. The diagnostic accuracy was analyzed by using the receiver operating characteristic curve (ROC).

RESULTS

There were 30 aggressive SPNs and 92 non-aggressive SPNs. Aggressive SPNs showed significantly higher frequencies of an ill-defined margin, patient age > 40.5 years, and tumor size < 42.1 mm, but lower frequencies of complete capsule, hemorrhage compared with non-aggressive SPNs (p < 0.05). Lack of complete capsule and age > 40.5 years were independent risk factors of aggressive SPNs (odd ratio 7.08 and 3.1, respectively). When we applied the two predictors in the logistic regression model, the area under the curve (AUC) was 0.77 with sensitivity of 86.7% and specificity of 55.4%.

CONCLUSION

Size less than 42.1 mm, lack of complete capsule, ill-defined, and absent bleeding are useful CT imaging features for predicating aggressive SPNs. Patient age > 40.5 years and lack of complete capsule showed acceptable diagnostic performance for discriminating aggressive from non-aggressive SPNs.

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.

Surgical Management of Solid Pseudopapillary Tumor of the Pancreas

Background and Objectives:

Although solid pseudopapillary tumor (SPT) of the pancreas is rare, its diagnosis has increased severalfold in the past decades. We present our experience in the management of SPT, including a patient who experienced tumor rupture during laparoscopy pancreatic resection.

Methods:

Data on all patients with SPT who were subjected to surgical treatment were retrospectively obtained.

Results:

Of 20 patients evaluated, 17 (85%) were females. The mean age was 31 years. Tumor size varied from 2.7 × 1.5 to 13.5 × 10.0 cm, with a mean of 6.4 × 7.6 cm. The most common location was the tail and/or body of the pancreas (14 patients [70%]). Pancreatic tumor resection was performed in 19 patients (50%). The type of resection depended on tumor location and size: distal pancreatectomy (n = 13), pancreatoduodenectomy (n = 5), and central pancreatectomy (n = 1) Pancreatic resection was performed via laparoscopy in 7 patients who underwent distal pancreatectomy. Tumor resection was not performed in only 1 patient (5%), due to invasion of mesenteric vessels and presence of liver metastases. One patient had tumor rupture during laparoscopic resection, with no apparent macroscopic dissemination of the tumor. All 19 patients who underwent SPT resection had no tumor recurrence, including a patient with capsule invasion and another patient with tumor rupture during surgical dissection. The mean follow-up time was 38 months (range, 6–72 months).

Conclusion:

Complete SPT resection is possible in most patients, with a low recurrence rate. Because of its large size, laparoscopic resection of SPT's should be performed only by experienced surgeons to avoid tumor rupture.

Asymptomatic versus symptomatic solid pseudopapillary tumors of the pancreas: clinical and MDCT manifestations

BACKGROUND

To delineate the features of multi-detector computed tomography (MDCT) images and clinical characteristics of pancreatic solid pseudopapillary tumors (SPTs) of the pancreas in asymptomatic patients and compare these features and characteristics between asymptomatic and symptomatic patients.

METHODS

This work is a retrospective study approved by our institutional review board. MDCT images and clinical data of 109 patients with pathologically proven SPTs obtained from October 2008 to October 2016 were reviewed. Patients were categorized into two groups: asymptomatic patients and patients with symptomatic disease. Cases were reviewed to determine the reason for detection, intervention, shape, diameter, location, calcification, encapsulation, internal composition, CT attenuation, enhancement pattern, and tumor pathology. Clinical factors and imaging features were also compared between groups. Statistical analysis was performed using χ2 and t-tests.

RESULTS

Data from 49 asymptomatic and 60 symptomatic patients were collected. Asymptomatic SPTs were identified most frequently during routine health examination (18 patients, 36.7%), various screening purposes (12 patients, 24.5%), and traumatic injury (9 patients, 18.4%). Except for a smaller tumor size (5.8 cm in asymptomatic SPTs vs. 7.4 cm in symptomatic SPTs, P = 0.023), the clinical factors or imaging features of asymptomatic patients were very similar to those of symptomatic patients.

CONCLUSIONS

The current research is the first single-center study to characterize SPTs in asymptomatic patients. Asymptomatic SPTs are gradually being identified with greater frequency. Although generally smaller in size than that in symptomatic patients, an asymptomatic pancreatic mass with the typical imaging features of SPT may be found, the treatment for which is similar to that for symptomatic patients. Evaluating asymptomatic SPTs requires further systematic and multi-center trials.

Clinicopathological Features and Treatment Outcomes of Solid Pseudopapillary Neoplasms of the Pancreas: A 10-Year Case Series from a Single Center

Background: Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare pancreatic tumors. This study summarizes the clinicopathological characteristics and treatment outcomes of SPN patients through a 10-year single-center case series. Materials and Methods: Medical records of patients diagnosed with SPNs and who underwent surgery between August 2007 and July 2017 at Qilu Hospital, Shandong University, were retrospectively analyzed. Results: This study included 91 patients: 13 males/78 females, mean age 28.8 ± 11.5 years. Among the cases, 38.5% were incidentally confirmed without specific symptoms, while the others displayed various abdominal symptoms. All patients had single pancreatic lesions, and 1 patient presented with liver metastasis. Abdominal enhanced computed tomography, magnetic resonance imaging, and endoscopic ultrasound were the diagnostic imaging techniques used to identify SPNs. All patients had successful surgical removal of their tumors; 28 patients underwent laparoscopy. During the 2-121-month follow-up period, 1 patient died of lung metastasis and multiple organ failure at 35 months postoperatively, but no other tumor recurrence or metastasis was found. Conclusions: SPN usually occurs in the young female population and presents with various clinical characteristics. Mixed solid-cystic masses with calcification or hemorrhage are typical morphological tumor features. Minimally invasive organ-/function-preserving operations are advocated for benign cases, while aggressive radical resection should be performed in patients with local invasion or distant metastasis.

Aggressiveness of solid pseudopapillary neoplasm of the pancreas: A literature review and meta-analysis

BACKGROUND

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare tumors considered to be benign although 10% to 15% of SPNs have been reported to be aggressive. Due to its rarity, there have only been a few cases reported regarding the clinical course of patients with aggressive SPNs. The goal of this study is to describe the clinical course of patients diagnosed with aggressive SPNs.

METHODS

A PubMed search was done looking for articles describing the clinical course of patients diagnosed with SPN that locally invaded, recurred, or metastasized. Institutional experience was also added to the pooled data. Patient information was extracted from the articles. Survival and recurrence curves were plotted and factors associated with survival and recurrences were analyzed.

RESULTS

A total of 59 patients were identified to have aggressive SPN. Seven patients were males and 52 were females and the mean age was 37.44 ± 2.21 years. Systemic metastasis constituted 81.4% while recurrence and deep tissue invasion were found in 11.9% and 6.8% of the patients, respectively. Disease-free survival was 45 ± 6.28 months and disease-specific survival was 152.67 ± 12.8 months. In survival analysis, age, gender, tumor size, tumor location, combined resection, type of recurrence, and stage IV on diagnosis were not significant factors in predicting survival. However, an unresectable tumor (hazards ratio [HR] = 4.871, 95% confidence interval [CI] 1.480-16.03, P = .009), and metastasis within 36 months (HR = 6.399, 95% CI: 1.390-29.452, P = .017) were identified as independent variables in predicting survival.

CONCLUSION

SPNs of the pancreas carry a favorable course. Despite having aggressive properties, patients can still survive for more than 10 years as long as the tumor can be resected completely.

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.

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.