Institutional experience with solid pseudopapillary neoplasms: focus on computed tomography, magnetic resonance imaging, conventional ultrasound, endoscopic ultrasound, and predictors of aggressive histology

Malignant Solid Pseudopapillary Neoplasm of the Pancreas: An Orthogonal Analysis

BACKGROUND

Pancreatic solid pseudopapillary neoplasms (SPN) are generally indolent; however, some patients present with "malignant" SPN. An orthogonal analysis of multiple datasets was performed to investigate the utility of complete surgical resection (CSR) for malignant SPN.

METHODS

A systematic review was performed for cases of malignant SPN, defined as T4, N1, and/or M1. Malignant SPN was analyzed within the National Cancer Database (NCDB) and compared with T1-3N0M0 SPN. Predictors of malignant SPN were assessed, and treatments were analyzed by using survival analysis.

RESULTS

The systematic review yielded 164 cases of malignant SPN. Of 31 children, only one died due to malignant SPN. Among adults, CSR was associated with improved disease-specific survival (DSS) (P = 0.0002). Chemotherapy did not improve malignant SPN DSS, whether resected (P = 0.8485) or not (P = 0.2219). Of 692 adults with SPN within the NCDB, 93 (13.4%) had malignant SPN. Pancreatic head location (odds ratio [OR] 2.174; 95% confidence interval [CI] 1.136-4.166; P = 0.0186) and tumor size (OR 1.154; 95% CI 1.079-1.235; P < 0.0001) associated with the malignant phenotype. Malignant SPN predicted decreased overall survival (OS) compared with T1-3N0M0 disease (P < 0.0001). Resected malignant SPN demonstrated improved OS (P < 0.0001), including resected stage IV malignant SPN (P = 0.0003). Chemotherapy did not improve OS for malignant SPN, whether resected (P = 0.8633) or not (P = 0.5734). Within a multivariable model, resection was associated with decreased hazard of death (hazard ratio 0.090; 95% CI 0.030-0.261; P < 0.0001).

CONCLUSIONS

Approximately 13% of patients with SPN present with a malignant phenotype. Pediatric cases may be less aggressive. Resection may improve survival for malignant SPN, which does not appear chemosensitive.

Presumed radiological diagnosis of solid pseudopapillary tumors: do we really know what we are watching?

OBJECTIVES

Little is known about the clinicians' ability to ascertain the identity of a pancreatic lesion as solid pseudopapillary tumors (SPT)preoperatively. We led this retrospective study to figure out the disease spectrum that mimic SPT, the key features of SPT and the accuracy of CT and MRI in characterizing them.

METHODS

Radiological and clinical database at a tertiary pancreatic disease center (Peking Union Medical College Hospital) was searched for patients who received CT or MRI with a presumed radiological diagnosis of SPT. Those patients' clinical information and final pathological diagnosis were collected.

RESULTS

During 2018.10-2021.12, 200 patients had a presumed radiological diagnosis of SPT, and 132 of them had unambiguous pathological diagnosis. SPT were confirmed in only 63.6% (84/132), while the others had a variety of neoplastic and nonneoplastic lesions, including pancreatic neuroendocrine tumors (n = 15), pseudocysts (n = 4), mucinous cystic neoplasms (n = 4), serous cystadenomas (n = 3), neural sheath tumors (n = 3), lymphoepithelial cysts (n = 2), and several very rare pathologies (n = 17). Of note, 11.4% (15/132) of those were benign or nonneoplastic lesions, while 6.8% (9/132) were neoplasms with highly aggressive nature, or pancreatic metastases, which require systematic evaluation and staging instead of upfront surgery. Retrospective radiological analysis based on key imaging features, clinical history and laboratory findings had an improved diagnostic accuracy of 78.5% with CT and 77.8% with MRI.

CONCLUSIONS

There is a broad disease spectrum mimicking SPT at CT and MRI. Key imaging features, clinical information and laboratory findings must be integrated to improve the diagnostic accuracy.

Preoperative prediction of invasive behavior of pancreatic solid pseudopapillary neoplasm by MRI-based multiparametric radiomics models

OBJECTIVE

A log-combined model was developed to predict the invasive behavior of pancreatic solid pseudopapillary neoplasm (pSPN) based on clinical and radiomic features extracted from multiparametric magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A total of 111 patients with pathologically confirmed pSPN who underwent preoperative plain and contrast-enhanced MRI were included, and divided into an invasive group (n = 34) and non-invasive group (n = 77). Clinical features and laboratory data related to pSPN invasive behavior were analyzed. Regions of interest were delineated based on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and contrast-enhanced T1WI (CE-T1WI) to extract radiomic features. Correlation analysis was performed for these features, followed by L1_based feature selection (C = 0.15). A logistic regression algorithm was used to construct models based on each of the four sequences and a log-combined model was used to integrate the sequences. A receiver operating characteristic (ROC) curve was plotted to evaluate the model performance, and the Brier score was used to assess the overall accuracy of the model predictions.

RESULTS

The area under the ROC curve was 0.68, 0.73, 0.71, and 0.49 for Log-T1WI, Log-T2WI, Log-DWI, and Log-CE models, respectively, and 0.81 for the log-combined model. The accuracy, precision, sensitivity, and specificity of the log-combined model were 0.77, 0.88, 0.75, and 0.78, respectively. The best performance was obtained with the log-combined model with a Brier score of 0.18. Tumor location was identified as a significant clinical feature in comparison between the two groups (p < 0.05), and invasive pSPN was more frequent in the tail of the pancreas.

CONCLUSION

The log-combined model based on multiparametric MRI and clinical features can be used as a non-invasive diagnostic tool for preoperative prediction of pSPN invasive behavior and to facilitate the development of individualized treatment strategies and monitoring management plans.

[Solid Pseudopapillary Neoplasm of the Pancreas in Children and Adolescents - Tailored Diagnostic and Operative Concepts in Four Patients]

BACKGROUND

Pancreatic tumors in children and adolescents are rare entities that can stay asymptomatic for long periods. They often become apparent as incidental findings or due to clinical symptoms, like abdominal pain. Solid pseudopapillary neoplasms of the pancreas (SPN) are rare representatives of this group, being low-grade malignant processes and requiring radical surgical treatment. We present four cases of SPN with different diagnostic and therapeutic approaches.

METHODS

A retrospective analysis of four cases of SPN treated between 2015 and 2020 was performed.

RESULTS

Four female patients (11-17 years) were found to have SPN during diagnostic procedures. Three of them were located in the pancreatic head. Histological confirmation was obtained with endosonographic-, CT-guided and open biopsy, respectively. R0 resection was achieved by a pylorus preserving, partial duodenopancreatectomy according to Traverso-Longmire. In one patient the tumor was located in the pancreatic tail with tumor adherence to the splenic vessels. A CT guided biopsy confirmed an SPN. A distal pancreatectomy and splenectomy was performed. Follow-up (6 months - 6 years) revealed no evidence of tumor recurrence, metastasis, or pancreoprive diabetes.

CONCLUSION

For the treatment plan preoperative histological confirmation of SPN is necessary. Based on the tailored diagnostic and operative concepts, treatment at a center with a specialized pediatric surgery, pediatric oncology, pediatric gastroenterology, pediatric radiology and pathology is mandatory.

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.

A case report of three synchronous tumors in the same pancreatic specimen

It is known that Duodenal adenocarcinoma (DA) is a rare malignant solid tumor that cause occlusion symptoms with orthodox dysphagia when locally advanced. Pancreatic neuroendocrine tumors (PanNETs) account for about 2% of all pancreatic neoplasms. The combination of these two lesions, with the synchronous presence of ectopic pancreatic tissue (EPT) of the duodenum, has never been described in literature, to our knowledge. Here we report a case of combined DA, EPT and PanNET affecting a 71-year-old woman.

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Simultaneous presence of Duodenal adenocarcinoma pancreatic neuroendocrine tumor ectopic pancreatic tissue of duodenum.

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Biochemical tests did not reveal abnormalities: CA 19-9 was normal, CEA was 153 U/L.

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Ultrasonography confirmed a nodule dislocating pancreas investigated with contrast-enhanced CT and esophagogastroduodenoscopy.

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The association between duodenal adenocarcinomas, PanNET and ectopic pancreatic tissue (EPT) of the duodenum is really rare.

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.

Preoperative neutrophil-to-lymphocyte ratio predicts malignancy and recurrence-free survival of solid pseudopapillary tumor of the pancreas

BACKGROUND

Systemic inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been shown to be prognostic for many types of pancreatic malignancy. The aim of this study was to evaluate the prognostic role of these markers in patients with solid pseudopapillary tumor of the pancreas (SPTP).

METHODS

Patients who underwent surgical resection for histologically confirmed SPTP were retrospectively reviewed in our institution. Preoperative NLR and PLR were calculated. Clinicopathologic data were correlated with the presence of malignant potential and recurrence-free survival (RFS).

RESULTS

A total of 113 patients with SPTP were included in this study. Of them, 23 were men and 90 were women, with a median age of 35 years (interquartile range, 25-44). The optimal cut-off values for malignant SPTP were 3.22 for NLR, and 75.5 for PLR, respectively. Univariate analysis showed that high NLR (>3.22) and white blood cell count more than 9.96 × 10⁹ /L were predictive of a malignant SPTP. Meanwhile, high NLR (P = 0.001) and age more than 35 years (P = 0.026) were associated with worse RFS. On multivariable analyses, high NLR was the only independent predictor of malignant SPTP (odd ratio 6.871; 95% confidence interval [CI], 1.482-31.864; P = 0.014) and RFS (hazard ratio 12.633; 95% CI, 1.758-90.790; P = 0.012).

CONCLUSIONS

This study highlights the supportive role of preoperative NLR in predicting malignancy and RFS of SPTP patients. Further studies including a larger cohort of patients are needed to corroborate our findings.

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.

Does Computed Tomography Have the Ability to Differentiate Aggressive From Nonaggressive Solid Pseudopapillary Neoplasm?

OBJECTIVE

The aim of the study was to assess the ability of contrast-enhanced computed tomography (CECT) to differentiate aggressive from nonaggressive solid pseudopapillary neoplasms (SPNs).

MATERIALS AND METHODS

Forty treatment-naive patients with pathologically proven pancreatic SPNs were included. Imaging characteristics were determined by consensus of 3 radiologists blinded to histopathologic aggressiveness. All patients underwent 4-phase CECT using a pancreatic protocol. The regions of interest of the tumor and the normal pancreas were documented on all phases. Lymph nodes were considered metastatic if greater than 1.0 cm in short-axis diameter.Fisher exact and Wilcoxon rank-sum tests were used to compare between aggressive and nonaggressive tumors.

RESULTS

No significant difference was noted between imaging covariates, such as internal hemorrhage, calcification, wall thickness perceptibility, vascular invasion, margins, cystic component, and pancreatic and biliary ductal dilation. Tumors with greater than 62.5 Hounsfield units and progressive enhancement during the delayed phase had aggressive characteristics (P = 0.03).

CONCLUSIONS

On delayed phase CECT, pathologically aggressive SPNs may show greater enhancement than nonaggressive SPNs.

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.

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

Cystic pancreatic lesions are increasingly diagnosed owing to the abundant use of cross-sectional imaging. Given their malignant potential, true pancreatic cysts should be considered for resection or periodic follow-up. Cystic lesions of the pancreas (CLPs) require further evaluation and management. Therefore, it is important to establish a solid diagnosis at the time of detection. Endoscopic ultrasound examination is the imaging modality of choice. Fine needle aspiration provides fluid for cytologic, biochemical, and molecular assays to classify lesions and predict biological behavior. This review provides an overview of the diagnosis and management of various types of commonly encountered true CLPs.

"Incidentalomas" on abdominal and pelvic CT in emergency radiology: literature review and current management recommendations

The purpose of this article is to familiarize radiologists and clinicians with a subset of common and uncommon incidental findings on abdominal and pelvic computed tomography examinations, including hepatic, splenic, renal, adrenal, pancreatic, aortic/iliac arterial, gynecological, and a few other miscellaneous findings, with an emphasis on "incidentalomas" discovered in the emergency setting. In addition, we will review the complex problem of diagnosing such entities, and provide current management recommendations. Representative case examples, which we have encountered in our clinical practices, will be demonstrated.

A rare case of three different tumors in the same pancreatic specimen: a case report and brief review of the literature

Solid pseudopapillary tumors (SPT) of the pancreas are rare neoplasms mainly affecting young women. Pancreatic serous cystadenomas (SCAs) and pancreatic neuroendocrine tumors (PanNETs) account for about 2% of all pancreatic neoplasms. The combination of these three lesions, to our knowledge, has never been described in literature. Here we report a case of combined SPT, SCA and PanNET affecting a 33-year-old woman.

Prognostic value of Ki-67 in solid pseudopapillary tumor of the pancreas: Huashan experience and systematic review of the literature

BACKGROUND

Solid pseudopapillary tumor of the pancreas (SPTP) is considered to have a low Ki-67 proliferation index, which may explain the generally good clinical outcome. The aim of our study was to evaluate whether Ki-67 has prognostic value in SPTP.

METHODS

A case series study of patients with SPTP treated in our institution from June 2002 to April 2014 was conducted. Prognostic factors for clinical outcomes were analyzed by the use of clinical decision and survival analysis. In addition, we performed a systematic review and pooled analysis to evaluate our results.

RESULTS

The institutional data included 71 patients (13 male and 58 female) ranging in age from 12 to 64 years (median, 31 years). Three patients developed local recurrence and/or liver metastasis after initial surgery. The 5-year recurrence-free survival rate was 93.6%. One patient died of disease, with the 5-year disease-specific survival rate of 98.5%. Ki-67 index ≥ 4% was found significantly associated with the survival of SPTP. Twenty-six studies comprising 163 patients were included in the pooled analysis based on our inclusion criteria. A total of 15 cases showed a Ki-67 index ≥ 4%. Kaplan-Meier survival analysis confirmed that Ki-67 index ≥ 4% was significantly associated with poorer recurrence-free survival and disease-specific survival (both P < .001).

CONCLUSION

This study highlighted a potential role of Ki-67 in predicting adverse outcome of patients with SPTP and should be considered as part of routine histological reporting of SPTP.

Pre-treatment carbohydrate antigen 19-9 does not predict the response to neoadjuvant therapy in patients with localized pancreatic cancer

BACKGROUND

The prognostic value of CA19-9 in patients with pancreatic cancer (PC) treated with neoadjuvant therapy has not been well described.

METHODS

Pre-treatment CA19-9 levels (with concomitant normal bilirubin level) in patients with localized PC were categorized as normal (≤35), low (36-200), moderate (201-1000), or high (>1000). Post-treatment CA19-9 was measured after neoadjuvant therapy, prior to surgery.

RESULTS

Pre-treatment CA19-9 levels were evaluable in 235 patients, levels were normal in 60 (25%) patients, low in 78 (33%) patients, moderate in 69 (29%) and high in 28 (12%). After neoadjuvant therapy, post-treatment CA19-9 normalized (≤ 35) in 40 (51%) of the patients in the low group, 14 (21%) of the moderate and 5 (19%) of the high group (P < 0.001). Of the 235 patients, 168 (71%) completed all intended therapy including a pancreatectomy; 44 (73%), 62 (79%), 46 (67%) and 16 (57%) of the normal, low, moderate and high groups (P = 0.10). Among these 168 patients, the median overall survival was 38.4, 43.6, 44.7, 27.2 and 26.4 months for normal, low, moderate and high CA19-9 groups (log rank P = 0.72). Among resected patients, an elevated pre-treatment CA19-9 was of little prognostic value; instead, it was the CA19-9 response to neoadjuvant therapy that was prognostic [hazard ratio (HR): 1.80, P = 0.02].

CONCLUSIONS

Among patients who completed neoadjuvant therapy and surgery, pre-treatment CA19-9 obtained at the time of diagnosis was not predictive of overall survival, but normalization of post-treatment CA19-9 in response to neoadjuvant therapy was highly prognostic.

Solid Pseudopapillary Neoplasm of the Pancreas: Analysis of Seven Cases

Background

The purpose of this study was to describe as well as compare our surgical treatment experiences of solid pseudopapillary neoplasms (SPN) of the pancreas and to provide a review of the literature.

Methods

A retrospective analysis of data from Vilnius University Hospital Santariskiu Klinikos (VUH SK) and of the literature, which was researched using Karger Publishers, Springer Science, BioMed Central, and disserCat databases, was conducted.

Results

From 2001 to 2012, seven cases were identified with pathologically confirmed SPN diagnosis. A precise preoperative diagnosis was made by computertomography and magnetic resonance imaging. The median diameter of the tumors was 6.36 cm (range 1.5-12 cm). Surgical treatment was undertaken for all patients. Results of the immunohistochemical analysis confirmed a nuclear accumulation of β-catenin. The Ki-67 level was 1-2% in all of the cases. According to our collected data, all types of histological analysis revealed decent prognostic behavior with low mitotic activity (1-2 mitoses per 50 high power fields). Besides, angioinvasion, perineural invasion, and outside capsule invasion were not detected.

Conclusions

There was no correlation between more aggressive types of SPN and tumor size, localization, age, and gender.

Solid-pseudopapillary tumor of the pancreas: MR imaging findings in 21 patients

PURPOSE

Solid-pseudopapillary tumor (SPT) of the pancreas is a rare, low-grade malignancy, which mostly occurs in adolescent and young adult females. The goal of this study was to retrospectively analyze the magnetic resonance (MR) imaging presentation of SPT of the pancreas.

METHODS

We retrospectively reviewed the preoperative MR imaging examinations and the medical, surgical and histopathological records of 21 patients who underwent surgery for SPT of the pancreas. MR imaging included T1-weighted, T2-weighted, and gadolinium chelate-enhanced MR imaging. In addition, 10 patients had diffusion-weighted (DW) MR imaging. MR examinations were retrospectively reviewed for location, size, morphological features and signal intensity of the tumors.

RESULTS

Nineteen women and 2 men (median age, 23 years; range, 14-59) were included. Seven patients (7/21; 33%) presented with abdominal symptoms. The median largest tumor diameter was 53mm (range, 32-141 mm). SPTs were located in the pancreatic head, body, and tail in 9 (9/21; 43%), 5 (5/21; 24%) and 7 (7/21, 33%) patients, respectively. All patients (21/21; 100%) had a single SPT. SPTs were more frequently oval (12/21; 57%), predominantly solid (12/21; 57%), fully encapsulated (16/21; 76%), larger than 30 mm (21/21; 100%), hypointense on T1-weighted MR images (21/21, 100%), hyperintense on T2-weighted MR images (21/21; 100%) and with an enhancing capsule after gadolinium-chelate administration (21/21; 100%).

CONCLUSIONS

There is trend of appearance for SPT of the pancreas on MR imaging but that variations may be observed in a number of cases. SPT uniformly presents as a single, well-demarcated and encapsulated pancreatic mass.