Diagnosis and treatment of solid-pseudopapillary tumors of the pancreas: A single institution experience with 97 cases

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.

Long-Term Oncologic Outcome following Duodenum-Preserving Pancreatic Head Resection for Benign Tumors, Cystic Neoplasms, and Neuroendocrine Tumors: Systematic Review and Meta-analysis

BACKGROUND

Pancreatoduodenectomy (PD) has a considerable surgical risk for complications and late metabolic morbidity. Parenchyma-sparing resection of benign tumors has the potential to cure patients associated with reduced procedure-related short- and long-term complications.

MATERIALS AND METHODS

Pubmed, Embase, and Cochrane libraries were searched for studies reporting surgery-related complications following PD and duodenum-preserving total (DPPHRt) or partial (DPPHRp) pancreatic head resection for benign tumors. A total of 38 cohort studies that included data from 1262 patients were analyzed. In total, 729 patients underwent DPPHR and 533 PD.

RESULTS

Concordance between preoperative diagnosis of benign tumors and final histopathology was 90.57% for DPPHR. Cystic and neuroendocrine neoplasms (PNETs) and periampullary tumors (PATs) were observed in 497, 89, and 31 patients, respectively. In total, 34 of 161 (21.1%) patients with intraepithelial papillar mucinous neoplasm exhibited severe dysplasia in the final histopathology. The meta-analysis, when comparing DPPHRt and PD, revealed in-hospital mortality of 1/362 (0.26%) and 8/547 (1.46%) patients, respectively [OR 0.48 (95% CI 0.15-1.58); p = 0.21], and frequency of reoperation of 3.26 % and 6.75%, respectively [OR 0.52 (95% CI 0.28-0.96); p = 0.04]. After a follow-up of 45.8 ± 26.6 months, 14/340 patients with intraductal papillary mucinous neoplasms/mucinous cystic neoplasms (IPMN/MCN, 4.11%) and 2/89 patients with PNET (2.24%) exhibited tumor recurrence. Local recurrence at the resection margin and reoccurrence of tumor growth in the remnant pancreas was comparable after DPPHR or PD [OR 0.94 (95% CI 0.178-5.34); p = 0.96].

CONCLUSIONS

DPPHR for benign, premalignant neoplasms provides a cure for patients with low risk of tumor recurrence and significantly fewer early surgery-related complications compared with PD. DPPHR has the potential to replace PD for benign, premalignant cystic and neuroendocrine neoplasms.

Solid pseudopapillary neoplasm (SPN) of the pancreas: current understanding on its malignant potential and management

Solid pseudopapillary neoplasms (SPN) of the pancreas are presently recognized as low-grade malignant tumors that are frequently observed in young females. This tumor has a low incidence and is associated with an excellent prognosis following surgical resection. Typical SPNs primarily affect the pancreas and tend to have moderate or asymptomatic manifestations. Based on retrospective research, it is anticipated that patients with SPN can achieve disease-free survival, even in cases when metastasis is detected during inspection. However, the incidence of malignant SPN has been consistently underestimated, as evidenced by recent research findings. Malignancy of SPN primarily encompasses invasion and infiltration, metastasis, and recurrence after R0 resection. Imaging technologies such as Ultrasound, Computed Tomography, Magnetic Resonance Imaging, and Position Emission Tomography are capable of preliminarily identifying malignant SPN, which is primarily based on its invasive clinical features. Research on risk factors of malignant SPN revealed that larger tumor size, Ki-67 index, and several other parameters had significant correlations with invasive tumor behavior. Pathologic features of malignant SPNs overlay other pancreatic tumors, nevertheless they can provide valuable assistance in the process of diagnosis. Several confirmed specific pathologic biomarkers are related to its cellular origin, characteristic gene mutation, and cell proliferation. Considering the invasiveness of malignant SPN, it is imperative to enhance the comprehensiveness of its therapy. Tumor resection remains a suggested course of action in line with typical SPN, and additional lymph node dissection is seen as reasonable. Compared to benign SPNs, malignant SPNs have worse prognosis, underscoring the necessity of early identification and treatment in comprehensive medical centers to get improved clinical outcomes.

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.

Complete enucleation of a complicated solid pseudopapillary neoplasm of pancreas: A case report

INTRODUCTION

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor, usually affecting young females. It is categorized as a low-grade malignant tumor without any specific epithelial differentiation, which can occur anywhere in the pancreas.

CASE PRESENTATION

Here, we present the case of a 35-year-old lady who presented to us with abdominal pain and a pancreatic mass. She had a prior laparotomy at a different center without any specific intervention for the lump. After presenting to our center, she was managed through proper evaluation and adequate preparation for surgery. The diagnosis was challenging, and so was the surgery. We had enucleated the lesion completely. Histopathology confirmed the diagnosis of SPN. There are no signs of recurrence after two years.

DISCUSSION

Patients are either asymptomatic or usually present with abdominal pain, a large abdominal lump, or some vague symptoms. A high index of suspicion is the key to diagnosis. Complete resection is the gold standard of treatment. Enucleation is also a good option in difficult cases. The prognosis after surgery is excellent.

CONCLUSION

Total enucleation of the SPN of the pancreas is a reasonable alternative in selected cases when performed by experienced hepatobiliary-pancreatic surgeons.

Histogram array and convolutional neural network of DWI for differentiating pancreatic ductal adenocarcinomas from solid pseudopapillary neoplasms and neuroendocrine neoplasms

PURPOSE

This study aimed to investigate the diagnostic performance of the histogram array and convolutional neural network (CNN) based on diffusion-weighted imaging (DWI) with multiple b-values under magnetic resonance imaging (MRI) to distinguish pancreatic ductal adenocarcinomas (PDACs) from solid pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine neoplasms (PNENs).

METHODS

This retrospective study consisted of patients diagnosed with PDACs (n = 132), PNENs (n = 45) and SPNs (n = 54). All patients underwent 3.0-T MRI including DWI with 10 b values. The regions of interest (ROIs) of pancreatic tumor were manually drawn using ITK-SNAP software, which included entire tumor at DWI (b = 1500 s/m²). The histogram array was obtained through the ROIs from multiple b-value data. PyTorch (version 1.11) was used to construct a CNN classifier to categorize the histogram array into PDACs, PNENs or SPNs.

RESULTS

The area under the curves (AUCs) of the histogram array and the CNN model for differentiating PDACs from PNENs and SPNs were 0.896, 0.846, and 0.839 in the training, validation and testing cohorts, respectively. The accuracy, sensitivity and specificity were 90.22%, 96.23%, and 82.05% in the training cohort, 84.78%, 96.15%, and 70.0% in the validation cohort, and 81.72%, 90.57%, and 70.0% in the testing cohort. The performance of CNN with AUC of 0.865 for this differentiation was significantly higher than that of f with AUC = 0.755 (P = 0.0057) and α with AUC = 0.776 (P = 0.0278) in all patients.

CONCLUSION

The histogram array and CNN based on DWI data with multiple b-values using MRI provided an accurate diagnostic performance to differentiate PDACs from PNENs and SPNs.

Minimally-invasive versus open pancreatic enucleation: systematic review and metanalysis of short-term outcomes

BACKGROUND

Minimally Invasive Pancreatic Enucleation, either laparoscopic or robot-assisted, is rarely performed. The aim of this study was to offer the current available evidence about the outcomes of minimally invasive pancreatic enucleations and explore the possible advantage of this approach over traditional surgery.

METHODS

PubMed (MEDLINE), Cochrane Library and Embase (ELSEVIER) medical databases were searched for articles published from January 1990 to March 2022. Studies which included more than 10 cases of minimally-invasive pancreatic enucleation were included. Data on the outcomes were synthetized and meta-analyzed when appropriate.

RESULTS

Twenty studies published between 2009 and 2022 with a total of 552 patients were included in the systematic review: three hundred fifty-one patients (63.5%) had a laparoscopic intervention, two hundred and one (36.5%) robot-assisted with a cumulative incidence of conversion rate of 5%. Minimally-invasive surgery was performed in 63% of cases on the body/tail of the Pancreas and in 37% of the cases on the head/uncinate process of the Pancreas. The cumulative post-operative 30 days - mortality rate was 0.2% and the major postoperative morbidity (Clavien-Dindo III-IV-V) 35%. Clinically relevant pancreatic fistula was observed in 17% of the patients. Compared with the standardized open approach (n: 366 patients), mean length of hospital stay was significantly reduced in patients undergoing minimally invasive pancreatic enucleation (2.45 days, p = 0.003) with a favorable trend for post-operative major morbidity (Clavien-Dindo III-IV) (- 24% RR, p: 0.13). Operative time, blood loss and clinically relevant pancreatic fistula rate were comparable between the two groups. One hundred and fourteen robot-assisted enucleations entered in a subgroup analysis with comparable results to open surgery.

CONCLUSION

Minimally-Invasive approach for pancreatic enucleation is safe, feasible and offers short-term clinical outcomes comparable with open surgery. The potential benefit of robotic surgery will need to be verified in further studies.

Prospects and applications of enucleation in solid pseudopapillary neoplasms of the pancreas

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare, low-grade, malignant neoplasms that are mostly seen in young women in the second and third decades of life and are quite uncommon in children. Standard resection for benign and borderline neoplasms of the pancreas is associated with a substantial risk of postoperative morbidity and long-term functional impairment, whereas enucleation leads to less morbidity and preserves healthy parenchyma as well as exocrine and endocrine function. Enucleation of SPNs has been increasingly reported to be feasible and safe for preserving the normal physiological function of the pancreas, especially in teenagers and children. This review summarizes findings published in recent years on the enucleation of SPNs as well as potential future developments and directions. Enucleation has undoubtedly come to stay as an alternative surgical procedure for SPNs. However, many questions remain unresolved, and future directions toward the best surgical indication, the prevention and intervention of complications, especially pancreatic fistula, intraoperative resection margin safety assessment, and long-term oncology prognosis remain to be evaluated and should be explored in future clinical trials.

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.

Non-gaussian models of 3-Tesla diffusion-weighted MRI for the differentiation of pancreatic ductal adenocarcinomas from neuroendocrine tumors and solid pseudopapillary neoplasms

PURPOSE

To assess the MRI performance in differentiating pancreatic ductal adenocarcinomas (PDACs), from solid pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine tumors (PNETs) using non-gaussian diffusion-weighted imaging models.

METHODS

This was a retrospective study of patients diagnosed with PDACs (01/2015-06/2019) or with PNETs or SPNs diagnosed (01/2011-12/2019) at our hospital. The lesions were randomized 1:1 to the primary and validation cohorts. The regions of interest (ROIs) were manually drawn on each slice at DWI (b = 1500 s/mm²) from 3 T MRI. D (diffusion coefficient), D* (pseudodiffusion coefficient), f (perfusion fraction), distributed diffusion coefficient (DDC), α (diffusion heterogeneity index), mean diffusivity (MD) and mean kurtosis (MK) were obtained. The parameters with largest performance for differentiation were used to establish a diagnostic model.

RESULTS

There were 148, 56, and 60 patients with PDAC, PNET, and SPN, respectively. For differentiating PDACs from SPNs, f and MK values were used to establish a diagnostic model with areas under the receiver operating characteristic curves (AUCs) of 0.92 and 0.89 in the primary and validation groups, respectively. For distinguishing PDACs from PNETs, α and MK values were used to establish a diagnostic model with AUCs of 0.87 and 0.86 in the primary and validation groups, respectively. The accuracy rate of the subjective evaluation with the assistance of non-gaussian DWI models for differentiating PDAC from SPNs and PNETs were higher than that of subjective diagnosis alone (P < 0.05).

CONCLUSIONS

The non-gaussian DWI models could assist radiologists in accurately differentiating PDACs from PNETs and SPNs.

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.

Solid pseudopapillary neoplasm-diagnostic approach and post-surgical follow up: Three case reports and review of literature

BACKGROUND

Solid pseudopapillary neoplasm (SPN) is a rare tumor that was first described by Frantz in 1959. Although this tumor is benign, some may have malignant potential that can be predicted based on demographics, imaging characteristics, and pathologic evaluation. This case series presents 3 SPN cases with discussion on gender differences, preoperative predictors of malignancy, and a suggested algorithm for diagnostic approach as well as post-surgical follow up.

CASE SUMMARY

Three adult patients in a tertiary hospital found to have SPN, one elderly male and two young females. Each of the cases presented with abdominal pain and were discovered incidentally. Two cases underwent endoscopic ultrasound with fine needle aspiration and biopsy to assess tumor markers and immuno-histochemical staining (which were consistent with SPN before undergoing surgery), and one case underwent surgery directly after imaging. The average tumor size was 5 cm. Diagnosis was confirmed by histology. Two patients had post-surgical complications requiring intervention.

CONCLUSION

Demographic and imaging characteristics can be sufficient to establish diagnosis for SPN, while malignant cases require pre-operative evaluation with endoscopic ultrasound fine needle aspiration/fine needle biopsy.

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.

Radiomics Analysis Based on Diffusion Kurtosis Imaging and T2 Weighted Imaging for Differentiation of Pancreatic Neuroendocrine Tumors From Solid Pseudopapillary Tumors

Objective

To develop and validate a radiomics model of diffusion kurtosis imaging (DKI) and T2 weighted imaging for discriminating pancreatic neuroendocrine tumors (PNETs) from solid pseudopapillary tumors (SPTs).

Materials and Methods

Sixty-six patients with histopathological confirmed PNETs (n = 31) and SPTs (n = 35) were enrolled in this study. ROIs of tumors were manually drawn on each slice at T2WI and DWI (b = 1,500 s/mm²) from 3T MRI. Intraclass correlation coefficients were used to evaluate the interobserver agreement. Mean diffusivity (MD) and mean kurtosis (MK) were derived from DKI. The least absolute shrinkage and selection operator regression were used for feature selection.

Results

MD and MK had a moderate diagnostic performancewith the area under curve (AUC) of 0.71 and 0.65, respectively. A radiomics model, which incorporated sex and age of patients and radiomics signature of the tumor, showed excellent discrimination performance with AUC of 0.97 and 0.86 in the primary and validation cohort. Moreover, the new model had better diagnostic performance than that of MD (P = 0.023) and MK (P = 0.004), and showed excellent differentiation with a sensitivity of 95.00% and specificity of 91.67% in primary cohort, and the sensitivity of 90.91% and specificity of 81.82% in the validation cohort. The accuracy of radiomics analysis, radiologist 1, and radiologist 2 for diagnosing SPTs and PNETs were 92.42, 77.27, and 78.79%, respectively. The accuracy of radiomics analysis was significantly higher than that of subjective diagnosis (P < 0.05).

Conclusions

Radiomics model could improve the diagnostic accuracy of SPTs and PNETs and contribute to determining an appropriate treatment strategy for pancreatic tumors.

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.

Application of Contrast-Enhanced Ultrasound in the Diagnosis of Solid Pseudopapillary Tumors of the Pancreas: Imaging Findings Compared With Contrast-Enhanced Computed Tomography

OBJECTIVES

The purpose of this study was to assess the characterization and usefulness of contrast-enhanced ultrasound (CEUS) for diagnosing solid pseudopapillary tumors of the pancreas (SPTP) and compare the enhancement patterns with contrast-enhanced computed tomography (CECT).

METHODS

Forty-three SPTP lesions proved by pathologic findings in 42 patients examined with CEUS and CECT were included in this study. The enhancement characteristics and typical CEUS features of the tumors were investigated. These characteristics were compared according to lesion sizes. The enhancement patterns of CEUS were compared with CECT.

RESULTS

The most common enhancement levels of SPTP in the early phase and late phase for CEUS were isoenhancement (19 of 43 [44.2%]) and hypoenhancement (32 of 43 [74.4%]), respectively. The 4 most common enhancement patterns were hypo-hypo (16 of 43 [37.2%]), iso-iso (11 of 43 [25.6%]), hyper-hypo (8 of 43 [18.6%]), and iso-hypo (8 of 43 [18.6%]) enhancement. For the 43 SPTP lesions, typical CEUS features such as lesion membrane, intralesional vessel, and intralesional compartmentalization enhancements were detected in 30 (69.8%), 27 (62.8%), and 10 (23.2%) cases. Compared with CECT, isoenhancement during the early phase and hypoenhancement during the late phase were the most common imaging characteristics of CEUS.

CONCLUSIONS

Lesion membrane, intralesional vessel, and intralesional compartmentalization enhancements are typical CEUS features of SPTP, especially for large lesions (lesion size ≥3.0 cm). Isoenhancement during the early phase and hypoenhancement during the late phase are the most common imaging characteristics of CEUS and CECT, making CEUS a viable alternative diagnostic method that is noninvasive.

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.

Pancreatic Solid Pseudopapillary Tumor Associated with Elevated DHEA and Testosterone

Solid pseudopapillary neoplasms (SPN) of the pancreas are extremely rare epithelial tumors with low malignant potential. They account for only 1-2% of pancreatic lesions. These masses often go unnoticed and when they become symptomatic it is often due to mass effect on neighboring structures. We encountered an unusual presentation in a healthy 34-year-old female who was found to have elevated dehydroepiandrosterone (DHEA) and testosterone levels during the evaluation of irregular menses. Subsequent abdominal imaging revealed an enhancing 2.7 cm pancreatic tail mass that was concerning for a pancreatic neoplasm. The patient underwent endoscopic ultrasound which confirmed the presence of a hypoechoic, 2.3 x 1.7 cm mass in the pancreatic tail. An intact interface was seen between the mass and adjacent structures, suggesting the absence of local invasion. Fine needle biopsy was performed and cytology was consistent with SPN. The patient later underwent curative distal pancreatectomy, with subsequent normalization of her menses. SPN are generally inactive on laboratory screening modalities (i.e., AFP, CEA, CA 19-9, and CA 125) and our patient showed no evidence of pancreatic insufficiency, pancreatic parenchymal injury, abnormal liver function, or cholestasis. Similarly to our patient, most SPN are asymptomatic. One retrospective study (spanning 15 years) reported vague abdominal pain in ~70% of patients, on initial presentation. Symptoms of tumor mass effect were the second most common. To our knowledge, this is the first reported presentation of elevated DHEA and testosterone levels associated with a solid pseudopapillary tumor in the absence of an underlying adrenal lesion or dysfunction. Despite extensive workup, no alternate etiology or correlatable medical condition could be elucidated for our patient's hormonal dysregulation. We, therefore, recommend further review and investigation into this potential correlative relationship in an effort to guide the future diagnosis and management of this unusual neoplasm.