Clinical and immunohistochemical features of 34 solid pseudopapillary tumors of the pancreas

Solid pseudopapillary tumor of pancreas: A report of two cases and literature review

Solid pseudopapillary neoplasm of the pancreas is rarely encountered in clinical practice. It is a tumor with a good prognosis and overall curative rates. It primarily affects young females in their twenties. It has characteristic imaging appearances, but a definite diagnosis requires histopathological examination. The treatment goal of solid pseudopapillary neoplasm is almost always curative and aims for complete resection of the mass. Here, we present 2 cases of this rare neoplasm. The first case was managed by laparoscopic distal pancreatectomy, while the second underwent a Whipple procedure for pancreatic head involvement.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Cinematic rendering of solid pseudopapillary tumors: Augmenting diagnostics of an increasingly encountered tumor

Pancreatic solid pseudopapillary tumors (SPTs) are a rare subset of pancreatic neoplasms, accounting for under 2 % of exocrine pancreatic tumors. The incidence of SPTs has shown a significant increase in the past two decades, attributed to heightened cross-sectional imaging utilization. These tumors often present with nonspecific clinical symptoms, making imaging a crucial tool in their detection and diagnosis. Cinematic rendering (CR) is an advanced 3D post-processing technique that generates highly photorealistic realistic images by accurately modeling the interaction of light within the imaged volume. This allows improved visualization of anatomic structures which holds potential to improve diagnostics. In this manuscript we present the first description of CR appearances of SPTs in the reported literature. Through showcasing a range of cases, we highlight the potential of CR in illustrating the diverse imaging characteristics of these unique neoplasms.

Endocrine therapy for metastatic solid pseudopapillary neoplasm of the pancreas: A case report

Solid pseudopapillary neoplasm (SPN) of the pancreas is an extremely rare tumor, associated with favorable prognosis and long-term survival in patients with advanced disease. However, limited data exist on systemic therapy for such patients. Herein, we present a case of a young woman with a history of SPN, who progressed after multiple surgical resections and chemotherapy regimens. The immunohistochemistry (IHC) showed overexpression of estrogen receptors (ER) and progesterone receptors (PR) in tumor tissue. The patient started to receive tamoxifen and showed a durable response to endocrine therapy.

Overview of the 2022 WHO Classification of Neuroendocrine Neoplasms

In this review, we detail the changes and the relevant features that are applied to neuroendocrine neoplasms (NENs) in the 2022 WHO Classification of Endocrine and Neuroendocrine Tumors. Using a question-and-answer approach, we discuss the consolidation of the nomenclature that distinguishes neuronal paragangliomas from epithelial neoplasms, which are divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The criteria for these distinctions based on differentiation are outlined. NETs are generally (but not always) graded as G1, G2, and G3 based on proliferation, whereas NECs are by definition high grade; the importance of Ki67 as a tool for classification and grading is emphasized. The clinical relevance of proper classification is explained, and the importance of hormonal function is examined, including eutopic and ectopic hormone production. The tools available to pathologists for accurate classification include the conventional biomarkers of neuroendocrine lineage and differentiation, INSM1, synaptophysin, chromogranins, and somatostatin receptors (SSTRs), but also include transcription factors that can identify the site of origin of a metastatic lesion of unknown primary site, as well as hormones, enzymes, and keratins that play a role in functional and structural correlation. The recognition of highly proliferative, well-differentiated NETs has resulted in the need for biomarkers that can distinguish these G3 NETs from NECs, including stains to determine expression of SSTRs and those that can indicate the unique molecular pathogenetic alterations that underlie the distinction, for example, global loss of RB and aberrant p53 in pancreatic NECs compared with loss of ATRX, DAXX, and menin in pancreatic NETs. Other differential diagnoses are discussed with recommendations for biomarkers that can assist in correct classification, including the distinctions between epithelial and non-epithelial NENs that have allowed reclassification of epithelial NETs in the spine, in the duodenum, and in the middle ear; the first two may be composite tumors with neuronal and glial elements, and as this feature is integral to the duodenal lesion, it is now classified as composite gangliocytoma/neuroma and neuroendocrine tumor (CoGNET). The many other aspects of differential diagnosis are detailed with recommendations for biomarkers that can distinguish NENs from non-neuroendocrine lesions that can mimic their morphology. The concepts of mixed neuroendocrine and non-neuroendocrine (MiNEN) and amphicrine tumors are clarified with information about how to approach such lesions in routine practice. Theranostic biomarkers that assist patient management are reviewed. Given the significant proportion of NENs that are associated with germline mutations that predispose to this disease, we explain the role of the pathologist in identifying precursor lesions and applying molecular immunohistochemistry to guide genetic testing.

The Sex Features of Patients With Solid Pseudopapillary Neoplasms of the Pancreas: A Retrospective Study

Background

Solid pseudopapillary neoplasms of the pancreas (SPNs) in male patients are more frequently reported. The aim of the study was to evaluate the sex features of SPN and the risk factors that predict tumor recurrence.

Methods

From 2013 to 2019, patients who were pathologically confirmed to have SPNs were retrospectively reviewed. The baseline study parameters were compared between males and females. A logistic regression model was established to identify the independent risk factors for tumor recurrence.

Results

In total, 221 patients were included in this study. Of them, 53 patients (24.0%) were males. Male patients were older than female patients (39.1 vs 31.6 years, P=0.001), and the tumor size in male patients was smaller than that in female patients (50.38 vs 39.65 mm, P=0.038). The preoperative imaging diagnostic accuracy was significantly higher in females than in males (70.5% vs 54%, P=0.02). SPNs in male patients tended to be misdiagnosed with other malignant tumors (37.7% vs 10.7%, P<0.0001), with a more solid component observed in images (66.8% vs 24.7%, P<0.0001). For immunohistochemical staining, the expression of beta catenin was significantly lower in male patients (P=0.002), and the expression of vimentin was the opposite (P=0.01). The overall survival rate and disease-free survival were not different. Based on multivariate analysis, older age [hazard ratio (HR)= 1.094, 95% confidence interval (CI): 1.005-1.190] and KI 67 index grade III (HR=12.029, 95% CI: 2.399-60.311) were independent risk factors for tumor recurrence.

Conclusion

The clinical and imaging features of SPN in males were not in full accord with those in females; however, the differences did not influence prognosis.

Solid pseudopapillary neoplasm of the pancreas with multiple liver metastases successfully managed with staged resection

Due to the rarity of the disease, there are no guidelines or consensus for the management of solid pseudopapillary neoplasm of the pancreas with liver metastasis. We describe a patient with solid pseudopapillary neoplasm of the pancreas with multiple liver metastases who was successfully managed with staged resection. A previously healthy 50-year-old female presented to the clinic with dull epigastric pain. The contrast-enhanced computed tomography showed a well-defined cystic lesion at the distal body and tail of the pancreas with multiple liver deposits. A core needle liver biopsy was suspicious of a hepatic epithelioid hemangioendothelioma. A distal pancreatectomy with splenectomy and a left hemi-hepatectomy were performed with a subsequent staged right posterior sectionectomy to address the inadequate future liver remnant. The final histology with immunohistochemistry revealed a pancreatic solid pseudopapillary neoplasm. The patient had satisfactory surgical and oncological outcomes with no recurrence. As these are slow growing tumours, appropriately spaced staged liver resection was feasible to allow hypertrophy of the liver remnant and physiological recovery of the patient. The discrepancy in the histology and cross-sectional imaging led to a pre-operative diagnostic dilemma, and the final diagnosis was reached after surgical resection. Thus, resectable metastatic solid pseudopapillary neoplasm of the pancreas may be offered a primary curative radical surgery before considering other treatment modalities.

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

[Rare pancreatic tumors]

Beyond pancreatic ductal adenocarcinoma, which is by far the most frequent pancreatic neoplasm, a great variety of tumors occur in the pancreas. They include solid and cystic masses and epithelial and nonepithelial neoplasms, and they show a great diversity in their biological behavior, ranging from benign tumors to highly aggressive neoplasms. As examples of rare pancreatic tumors, clinical, morphological, and molecular aspects of acinar cell carcinoma, pancreatoblastoma, solid pseudopapillary neoplasm, and serous cystic neoplasms are presented and discussed.

[Solid pseudopapillary neoplasms of the pancreas : Diagnostics, surgical treatment and postoperative outcome]

BACKGROUND

Malignant solid pseudopapillary neoplasms (SPN) are rare tumor entities of the pancreas. The prognosis for SPN is generally excellent, although some tumors have malignant potential and tend to metastasize or relapse.

OBJECTIVE

The aim was to investigate whether there are histopathological or surgical risk factors that enable the biological potential of SPN to be estimated.

PATIENTS AND METHODS

Data from patients with SPN treated in two large German pancreas centers from 2009 to 2018 were evaluated with respect to the occurrence of SPN, surgical management, histopathological tumor characteristics and the postoperative outcome.

RESULTS

A total of 22 patients with SPN (17 women, 5 men) were operated on. The median age of the patients was 37 years (range 19-69 years). At the time of surgery 20 patients showed tumor growth limited to the pancreas. A female patient with recurrence of an externally resected SPN had lymph node involvement. Another female patient had a hepatic metastatic recurrence (Union Internationale contre Cancer (UICC) stage IV) of an externally resected SPN. Although all patients survived recurrence-free during the follow-up, this patient developed liver metastases again. The survival rate up to the end of the follow-up (median 43 months; range 1-132 months) of this study was 100%.

CONCLUSION

There is a lack of knowledge of the possible parameters that can be used to predict the biological behavior of SPN. Apart from an increased likelihood of recurrence after resection of an SPN recurrence, no clear risk factors could be identified in the examined patient collective that could indicate an increased malignant potential and a possibly poorer outcome. Only a radical surgical resection with lymphadenectomy enables a reliable assessment of the tumor stage and the removal of possibly affected lymph nodes, which could be the cause of a recurrence if left intact.

Solid Pseudopapillary Neoplasms of the Pancreas: a Single-Center Experience and Review of the Literature

PURPOSE

Pancreatic solid pseudopapillary neoplasms (SPNs) are rare borderline tumours mainly affecting young female patients. The number of patients diagnosed with SPNs has increased significantly in the last decades owing to the increased use of cross-sectional imaging investigating different abdominal symptoms, whilst a significant proportion are incidentally discovered during the process of evaluating other pathologies. We herein present our institutional experience of patients with SPN who underwent curative resection focusing on clinical, pathological features, and the long-term outcomes.

METHODS

All patients undergoing pancreatectomy in our institution for SPN from January 2010 until December 2018 were included. Clinical, perioperative, histological, and long-term outcomes were collected and analysed.

RESULTS

During the inclusion period, a total of 19 patients had a pathological diagnosis of SPNs after surgical resection. Sixteen of them were female (84%), while the median patient age was 30 (range 16-66) years. Nine patients (47%) underwent distal pancreatectomy and splenectomy, 2 (11%) underwent spleen preserving distal pancreatectomy, 6 (32%) underwent pancreatoduodenectomy, one (5%) underwent total pancreatectomy, and one (5%) central pancreatectomy. Seventeen patients underwent R0 resection. During a median follow-up of 23 months, no tumour recurrence or death was recorded.

CONCLUSION

In our experience, SPNs are rare tumours with low malignant potentials. Surgical resection remains the gold standard treatment and is associated with good prognosis.

A case of repeat hepatectomy for liver metastasis from solid pseudopapillary neoplasm of the pancreas: a case report

Background

Solid pseudopapillary neoplasm of the pancreas is a rare tumor in young women, metastasizing in only 5–15% of cases, and most commonly to the liver. Although treatment guidelines have not been established, surgical resection is usually performed. We report a rare case of repeat hepatectomy for liver metastases after distal pancreatectomy with solid pseudopapillary neoplasm.

Case presentation

The patient was a 71-year-old woman who underwent distal pancreatectomy for solid pseudopapillary neoplasm, and liver metastasis occurred 4 years after the first surgery. Partial liver resection was performed for four liver metastases, and histopathological examination revealed a diagnosis of liver metastasis from solid pseudopapillary neoplasm. However, 18 months later, liver metastases were detected again; three tumors were identified, and partial resection was performed, which has provided 18 months’ recurrence-free survival.

Conclusions

Long-term prognosis can be expected following R0 resection for resectable liver metastasis from solid pseudopapillary neoplasm.

Atypical solid pseudopapillary tumor of the pancreas in a 14-year-old

Diagnostic approach can be difficult in pediatric pancreatic masses. Our case shows that even though radiologic appearance was not conclusive, surgery remains the main treatment in resectable masses especially in children.

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

Background

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

Methods

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

Results

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

Conclusions

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

A Morphologic and Immunohistochemical Comparison of Nuclear β-Catenin Expressing Testicular Sertoli Cell Tumors and Pancreatic Solid Pseudopapillary Neoplasms Supporting Their Continued Separate Classification

Some recent reports suggested that many Sertoli cell tumors, not otherwise specified (SCTs-NOS) of the testis were analogs of the solid pseudopapillary neoplasm (SPN) of the pancreas. One of the most relied on pieces of information for this assertion was the shared occurrence in both neoplasms of exon 3 mutations of the CTNNB1 gene, which was reflected by nuclear β-catenin expression. We, therefore, compared the morphologic and immunohistochemical features of 18 SCTs-NOS with strong, diffuse nuclear β-catenin expression with 16 SPNs that also showed such positivity. Although there were clear similarities in the light microscopic features of these neoplasms, there were also significant differences that included, in SCT-NOS and SPN, respectively: hollow tubules (53% vs. 0%), sheet-like growth (44% vs. 94%), circumscription (79% vs. 25%), corded or trabecular patterns (81% vs. 31%), formation of papillae or pseudopapillae (24% vs. 69%), growth in nests or clusters (94% vs. 50%), perivascular pseudorosettes (13% vs. 56%), and rhabdoid cytology (6% vs. 50%). Commonly shared morphologic features included signet-ring cells, pale or foamy cytoplasm, myxoid stroma, cyst formation, perivascular hyalinization, and globular or band-like basement membrane deposits. On immunohistochemical study, sex cord markers were frequently positive in SCTs-NOS (steroidogenic factor-1-94%; FOXL2-87%; SOX9-69%; calretinin-60%; Wilms tumor-1-38%; inhibin-29%) whereas all of these markers were negative in the SPNs. We conclude that even though SCT-NOS and SPN share some morphologic features and nuclear immunoreactivity for β-catenin, there remain differences, both morphologically and immunohistochemically, between these neoplasms to the degree that SCT-NOS should not be equated with pancreatic SPN.

Sex differences in solid pseudopapillary neoplasm of the pancreas: A population-based study

Objective

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor. This study aims to examine the clinicopathological features and surgical treatments of SPN and compare the clinical behavior and prognosis between men and women with SPN.

Methods

We collected the population data of patients with SPN diagnosed between 2004 and 2017 from the SEER database. The Kaplan‐Meier method was used to analyze overall survival (OS) and disease‐specific survival (DSS), and log‐rank tests were used to evaluate the differences between subgroups. Univariate and multivariate Cox regression analyses were performed to screen out prognostic risk factors of SPN.

Results

A total of 378 patients with SPN were included, with 246 (65.1%) female patients. 1‐, 3‐, and 5‐year overall survival rates were 98.9%, 95.7%, and 93.7%, respectively. Survival analysis revealed that regardless of stage, patients with SPN who underwent surgical interventions still had a significantly better prognosis than those without surgical interventions (P < .001). The patients with lymphatic dissection had a significantly better prognosis than those without lymphatic dissection (P < .001). Moreover, compared with female patients, male patients had significantly poorer OS and DSS (P < .001). Female SPN showed a bimodal age‐frequency distribution with early‐onset incidence at 28 years and late‐onset peak incidence at 62 years, while male SPN presented a unimodal distribution with peak incidence at approximately age 64 years. In female patients, the tumor size in premenopausal females (<65 years old) was significantly larger than that in postmenopausal females (≥65 years old) (P < .001). Clinicopathological characteristic profiles were different not only between male SPN and premenopausal female SPN but also between premenopausal and postmenopausal female SPN.

Conclusion

SPN presents indolent behavior and predominantly occurs in young women. Regardless of stage, surgical intervention is recommended. Moreover, our study is the first large enough study to demonstrate sex‐related discrepancies in SPN. Thus, different treatment strategies should be designed for patients of different sexes at different ages and hormone therapy is a promising approach for SPN.

Solid pseudopapillary neoplasia of the pancreas: a review

OBJECTIVES

To review the literature and the diagnosis of conventional histopathological routine and immunohistochemistry of the cases diagnosed with Solid Pseudopapillary Neoplasm of the Pancreas (SPNP).

METHODS

The review of the literature was done using the Pubmed and solid Google-Scholar databases, through the historical, clinical aspects and diagnostic methods of SPNP. The review of SPNP cases diagnosed in the University Hospital Clementino Fraga Filho was carried out from 1977 to 2018.

RESULTS

Intratumoral phenotypic heterogeneity of SPNP was evidenced in the cases studied, taking into account macroscopic, microscopic, and immunohistochemical patterns.

CONCLUSIONS

The results show the importance of the examination of several fragments obtained from different regions of the neoplasia since not all of them present the same molecular alterations.

Solid pseudopapillary neoplasm of the pancreas: a report of 10 cases and literature review

BACKGROUND

Solid pseudopapillary tumour of the pancreas (SPTP) is a rare pancreatic tumour characterized by a non-specific clinical presentations and vague radiologic features. The aim of this study is to identify these tumours from other pancreatic neoplasms because complete resection is curative in most cases and provides long-term survival.

METHODS

A retrospective analysis of patients operated for SPTP between January 2000 and December 2018 was conducted. The collected data included age, gender, clinical findings, laboratory tests, radiological findings, anatomopathological examination, immunohistochemistry results, surgical treatment, mortality, morbidity and recurrence.

RESULTS

Ten cases of SPTP have been diagnosed between January 2000 and December 2018 representing 5.1% of all pancreatic tumours operated during this period (male/female: 2/8; median age 41.2 years; range 19-78 years). The most common symptom was abdominal pain and physical examination was normal in four of 10 cases. The most common tumour localization was the tail of the pancreas. The main tumour size was 7.2 cm (range 2-15 cm). One patient had abdominal disseminated disease. Surgical interventions were distal pancreatectomy in five cases, enucleation in one case, cephalic duodeno-pancreatectomy in two cases, central pancreatectomy in one case and pancreatic biopsy in one case. Only one patient received adjuvant chemotherapy. During follow-up, one patient died after 12 months and another developed unique hepatic metastasis that was resected.

CONCLUSION

Although it is delayed in diagnosis, the overall prognosis of these tumours remains good even with local recurrence and metastasis. Complete surgical resection is the treatment of choice even in cases of recurrence.

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.

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.

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.

Cytologic criteria to reduce error in EUS-FNA of solid pseudopapillary neoplasms of the pancreas

INTRODUCTION

Standardization of error classification in pathology remains an important issue. This study assesses the extent of error in cytopathologic diagnosis of solid pseudopapillary neoplasms (SPN) of the pancreas. Because of morphologic overlap of SPN and pancreatic neuroendocrine neoplasms (NET), we compared cytologic characteristics to determine which best distinguishes these entities.

MATERIALS AND METHODS

We collected cases diagnosed as SPN either by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) by cytology or surgical pathology from January 2000 to March 2013. An equal number of NET cases were randomly selected. Cytology and surgical pathology cases were evaluated for diagnostic errors and patient impact. Cytologic features in SPN and NET were scored based on presence of previously described characteristics.

RESULTS

A total of 17 patients with EUS-FNA were diagnosed with SPN by cytology or surgical pathology. Of those, 14 had surgical follow-up and 13 had adequate cell blocks and immunohistochemistry. There were 5 discrepancies between cytology and surgical pathology (5 of 14, 36%). There were no false positives or false negatives, but 5 misclassifications: 4 diagnosed as NET on cytology, and 1 as NET versus SPN. All misclassification errors were associated with no harm. When compared with NET, fine chromatin, nuclear grooves, pseud papillae, pink stroma, and hyaline globules are statistically significantly associated with SPN.

CONCLUSIONS

EUS-FNA of pancreatic SPN has excellent positive and negative predictive value, with no false positives or false negatives in this 12-year study. Only misclassification errors as pancreatic NET were made with minimal impact. We suggest that the presence of 3 of 5 major cytologic criteria offer accuracy in diagnosing SPN to prevent misclassification.

Solid pseudopapillary tumor of the pancreas: clinical-pathological features and management of 13 cases

Background and aim

Solid pseudopapillary tumor (SPT) of the pancreas is a rare pathological condition, representing less than 3% of all exocrine pancreatic tumors. SPT usually occurs in young females, without notable symptoms, with a low malignant potential and excellent prognosis.

Method

We conducted a retrospective study during the period January 2005 – January 2015. SPT patients admitted in our institution were reviewed by describing demographic data, clinico-pathologic and radiological features, therapeutic management and prognosis records.

Results

Thirteen patients with SPT were identified (10 females), with a median age of 30 years. The main clinical presentation was abdominal pain (92.3%). The tumor was mostly located in the body or tail of the pancreas (77%), and the mean size was 8.2 cm. Regarding the surgical approach there were 5 distal pancreatectomies with splenectomy, 3 body and tail pancreatectomies, 2 body and tail pancreatectomies with splenectomy, 2 pancreato-duodenectomy, 1 partial enucleation and of all only 2 partial resections. Postoperative hematoxylin- eosin staining and immunohistochemistry confirmed the diagnosis in all cases. None of the patients had lymph nodes metastases. Only one local invasion. There was one case of death due to postoperative complications. Four cases followed adjuvant systemic chemotherapy. The mean follow-up was 18 months, without evidence of recurrence during this period.

Conclusion

SPT should always be considered in the differential diagnosis in young women with a pancreatic tumor. Complete surgical excision is the treatment of choice, and is usually curative. The decision to administer systemic therapy must be individualized. Malignant behavior and late recurrences mandates long-term follow-up for patients with SPT.

Prognostic role of sex steroid receptors in pancreatic adenocarcinoma

From the available literature, it is unclear what proportion of pancreatic adenocarcinomas express estrogen receptors (ERα, ERβ), progesterone receptors (PR), and androgen receptors (AR), and if any of these markers have prognostic significance. We aimed to assess (1) the expression and (2) the correlation of the aforementioned markers with clinicopathological parameters and prognosis in patients with pancreatic adenocarcinoma. During a five-year period, 60 patients with pancreatic ductal adenocarcinoma underwent surgical resection at a single institution. Immunohistochemical stains of the studied markers were quantified by Image analysis system. ERα expression was positively associated with PR expression. Moreover, ERβ was inversely associated with the presence of metastases, whereas no significant associations implicated AR. As far as the prognostic significance of the studied receptors is concerned, higher ERα expression correlated with poorer survival at the univariate analysis, but the finding dissipated at the multivariate approach. No significant associations with overall survival were noted regarding the other receptors. The role of sex hormone receptors in the survival from pancreatic adenocarcinoma seems rather limited. Further prospective studies assessing those receptors should ideally be designed in order to confirm our results and possibly outline additional correlations between other steroid receptors and features of pancreatic adenocarcinoma.

Solid Pseudopapillary Neoplasms of the Pancreas: a 19-Year Multicenter Experience in China

AIM

The aim of this study was to determine the clinicopathological features, surgical management, and prognosis of solid pseudopapillary neoplasms (SPNs) of the pancreas.

METHODS

This study conducted a retrospective analysis of 97 patients who underwent surgery for a pathologically confirmed SPN in five hospitals between January 1996 and December 2014.

RESULTS

The 97 cases included 93 female and 4 male patients, and the average age was 31.2 years. The tumor was located in the body or tail (70.1%), the head (20.6%), and the neck (9.3%). All patients underwent surgical exploration, including distal pancreatectomy (63.9%), pancreaticoduodenectomy (20.6%) (partial portal vein or superior mesenteric vein resection and artificial vascular graft reconstruction performed in 4.1% of the patients), central pancreatectomy (10.3%), enucleation (5.2%), and liver resection (1.0%). 16.5% of the patients had malignant tumors. The positive rate of Ki-67 was 66.7% in patients diagnosed with a malignant neoplasm and was comparable to 8.4% of the patients diagnosed to have a benign neoplasm (p < 0.001). After a median follow-up of 70.1 months, three patients had recurrence and one patient died of liver metastasis.

CONCLUSIONS

SPN is a rare neoplasm with low malignant potential. Surgical resection is warranted even in the presence of local invasion or metastases as patients demonstrate excellent long-term survival. Positive immunoreactivity for Ki-67 may predict the malignant potential and poor outcome of SPNs.

Solid pseudopapillary tumor of the pancreatic: evaluation of clinical, radiological and surgical profiles

OBJECTIVE

To describe the clinical, radiological and surgical features of solid pseudopapillary tumor of the pancreas.

METHODS

We conducted a retrospective, observational study evaluating the multi-institutional clinical, radiological and surgical patients with a diagnosis of solid pseudopapillary tumor of the pancreas undergoing surgical treatment.

RESULTS

We identified eight patients in three hospitals in the state of Amazonas, seven females, six under the age of 30. The neoplasia predominated in the head of the pancreas. Five patients underwent pancreaticoduodenectomy, one enucleation, one distal pancreatectomy, and one was considered unresectable.

CONCLUSION

Solid pseudopapillary tumor of the pancreas predominated in young female patients, predominantly located in the pancreatic head.

Multiple liver metastases of pancreatic solid pseudopapillary tumor treated with resection following chemotherapy and transcatheter arterial embolization: A case report

A 33-year-old female was diagnosed with a solid pseudopapillary tumor (SPT) of the pancreas and multiple liver metastases at the Department of Gastroenterological Surgery, Ishikawa Prefectural Central Hospital (Kanazawa, Japan). Distal pancreatectomy and postoperative systemic chemotherapy with gemcitabine (GEM) and S-1, an oral fluoropyrimidine derivative, was administered, however, liver metastases became enlarged and local recurrence occurred. Therefore, the patient was referred to the Department of Gastroenterologic Surgery at the Graduate School of Medicine (Kanazawa, Japan) for hepatic arterial infusion (HAI) chemotherapy. Oral S-1 (80 mg/m²) was administered as well as HAI chemotherapy with GEM (1,000 mg/standard liver volume). Following 18 cycles, tumor sizes were reduced and 18-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) examination revealed obvious reduction of tumor FDG uptake. Transarterial tumor embolization (TAE) was performed for the previously unresectable right subphrenic liver tumor, and the other tumors were surgically resected. The resected tumors were diagnosed as liver metastases and a local recurrence of SPT in the postoperative pathological examination, which revealed that the resected tumors were composed of sheets of bland cells, which were positive for CD10, CD56, vimentin, neuron-specific enolase and α-antitrypsin. The postoperative course was uneventful, and the patient is currently under observation at an outpatient clinic; postoperative adjuvant chemotherapy with oral S-1 has continued, and additional TAE is planned. In the future, if the middle segment of the liver becomes enlarged, surgery for the residual right lobe tumor may be possible. This case demonstrates one method of SPT treatment: Preoperative HAI chemotherapy with GEM, plus oral S-1 and TAE. If complete resection can be achieved, the majority of patients with SPT have a favorable prognosis. In patients with unresectable metastases from SPT, it is crucial to conduct systematic multimodal treatment to maximize treatment success.

Proteomic analysis of solid pseudopapillary tumor of the pancreas reveals dysfunction of the endoplasmic reticulum protein processing pathway

Solid pseudopapillary tumor of the pancreas (SPTP) is a low-grade malignant tumor with a favorable prognosis after surgery. Many previous studies have focused on clinical features or pathological biomarkers of the disease, but a better understanding of the molecular mechanisms underlying SPTP may help guide future therapeutic strategies. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) technology integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify differentially expressed proteins in SPTP specimens. A total of 1171 proteins with a threshold of a 1.5-fold change and a p value ≤ 0.05 between SPTP tissue and matched normal pancreas tissue were identified for bioinformatics analysis. Mass spectrometry results were then further confirmed by assessing six representative proteins (ACADL, EPHX2, MSI2, DKK4, JUP, and DAD1) in individual specimens with immunohistochemistry. Upon mapping of the differentially expressed proteins to the Kyoto Encyclopedia of Genes and Genomes pathways database, we found several new cell-adhesion molecules that could be used as pathologic biomarkers. Furthermore, we observed that many endoplasmic reticulum-associated proteins were altered, suggesting that endoplasmic reticulum stress may play an important role in SPTP tumorigenesis. Seven proteins (ERO1LB, TRIM1, GRP94, BIP, SEC61B, P4HB, and PDIA4) in this pathway were further validated by immunohistochemistry, and six of them (except SEC61B) coincided to the LC-MS/MS results. This first comprehensive analysis of the SPTP proteome confirms proteins that have been implicated in earlier reports and reveals novel candidates and pathways that could be investigated further for clinical applications.

Clinical and pathological features of solid pseudopapillary neoplasms of the pancreas at a single institution

AIMS

The aim of this study was to determine the clinicopathological features and surgical management of solid pseudopapillary neoplasms (SPNs) of the pancreas at a single institution.

METHODS

We investigated 34 patients (5 males and 29 females) who underwent surgery for pathologically confirmed SPNs between 1994 and 2012.

RESULTS

Clinical symptoms were absent in 58.8% of the patients. The median tumor diameter was 42.7 mm. All tumors were successfully removed by R0 resection. Pathologically, 5.9% had duodenum invasion and 2.9% had pancreatic serosal invasion, but there was no lymph node metastasis. Radiological findings showed calcification in 39.4% of the patients, capsule formation in 51.5%, cystic components in 69.7%, solid components in 93.9% and internal bleeding in 36.4%. Immunohistochemically, neuron-specific enolase was positive in 100% of the patients, nuclear accumulation of β-catenin in 100% and CD10 in 78.8%. There were no recurrences reported at the median follow-up (67 months). Regarding gender differences, the cystic component in radiological imaging was the only significant finding among the features studied (p = 0.01).

CONCLUSIONS

R0 resection with appropriate procedures appears to be sufficient for patients with SPNs, even for locally invasive tumors. There were no significant differences between genders except for the cystic component on radiological imaging.

Solid pseudopapillary neoplasm of the pancreas: a case report with review of the diagnostic dilemmas and tumor behavior

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of the pancreas often detected initially on imaging. Of uncertain histogenesis, it has a low-grade malignant potential with excellent post-surgical curative rates and rare metastasis. Despite advances in imaging, pseudocysts and other cystic neoplasms feature in the differential diagnosis. Pathological and/or cytological evaluation remains the gold standard in reaching a definitive diagnosis. On morphology alone, other primary pancreatic tumors and metastatic tumors pose a diagnostic challenge. Recent advances in immunohistochemical characterization have made the histopathologic diagnosis more specific and, in turn, shed light on the likely histogenesis of this rare tumor. We report a case of solid pseudopapillary neoplasm of the pancreas that was suspected on radiology and diagnosed intraoperatively on imprint cytology guiding definitive surgery. The diagnostic dilemmas are reviewed.

Cercariform cells: another cytologic feature distinguishing solid pseudopapillary neoplasms from pancreatic endocrine neoplasms and acinar cell carcinomas in endoscopic ultrasound-guided fine-needle aspirates

BACKGROUND

Solid pseudopapillary neoplasm (SPPN) is a rare tumor of unknown origin that occurs predominantly in the body or tail of the pancreas in young women. The authors recently identified cercariform (Greek: tailed) cells, similar to those described in urothelial carcinomas, as a consistent cytologic feature in ultrasound-guided fine-needle aspiration (EUS-FNA) samples from SPPNs. The objective of the current multi-institutional study was to define the value of these cells in the differential diagnosis of SPPN with other neoplasms characterized cytologically by the presence of monotonous, uniform cells in pancreatic aspirates: pancreatic neuroendocrine tumors (Pan-NETs) and acinar cell carcinomas (ACCs).

METHODS

The files of 4 academic hospitals were searched for SPPNs, Pan-NETs, and ACCs that were diagnosed by EUS-FNA. The slides were reviewed, and several cytologic features were recorded semiquantitatively to identify discriminating features between SPPNs, Pan-NETs, and ACCs.

RESULTS

From the analysis of 18 SPPNs, 4 ACCs, and 20 Pan-NETs, the following cytologic features were identified as common to all 3 neoplasms: single cells and rosettes/acinar cell groups, round-to-plasmacytoid cells, pale-to-granular cytoplasm, fine vacuoles, and binucleated cells. Papillary structures, cercariform cells, large cytoplasmic vacuoles, reniform nuclei, hyaline globules/magenta-colored material, and degenerative features (cholesterol crystals, calcifications, foam cells, or giant cells) were significantly more common in SPPNs. Prominent nuclear grooves were encountered in only 4 of 18 SPPNs.

CONCLUSIONS

The current results indicated that the presence of cercariform cells is another useful clue for the cytologic diagnosis of SPPN in challenging cases.

Solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasms (SPNs) are rare entities accounting for between 0.13 and 2.7 per cent of pancreatic tumours. This neoplasm has a predilection for females under the age of 35. The authors report this case of a SPN incidentally discovered when a 59-year-old female underwent a chest x-ray to investigate a wheeze. A subsequent CT abdomen revealed a 10 cm well-circumscribed mass adjacent to the tail of the pancreas. This mass was successfully resected. Immunohistochemical markers established the diagnosis of a SPN. The wheeze associated with the presentation of this case was unrelated to the tumour which was an incidental finding. These neoplasms are largely asymptomatic and indolent reaching a large size before detection. Diagnosis is confirmed on histology and in this case surgical resection was curative and there was no metastasis at presentation.

Solid-pseudopapillary neoplasms of the pancreas: clinical and pathological features of 33 cases

PURPOSE

Solid-pseudopapillary neoplasms (SPNs) are rare pancreatic tumors, with a low potential for malignancy. The clinical and pathological features of 33 SPNs were reviewed.

METHODS

This study conducted a retrospective analysis of 33 patients who underwent surgery for a pathologically confirmed SPN from 2000 to 2011.

RESULTS

Thirty of the 33 patients (91 %) were female, and the median age at diagnosis was 29.2 years (range 12-59). The most common symptom was abdominal discomfort with dull pain (58 %). Others included asymptomatic lesions that were only detected incidentally during imaging (21 %), a palpable abdominal mass (15 %) and indigestion (6 %). All 33 patients underwent surgery with a curative intent and 3 (9 %) underwent laparoscopic surgery. The mean diameter of the tumors was 4.9 cm (range 2-15 cm), and they occurred in the head (9, 27 %), neck (5, 15 %), body or tail (19, 58 %) of the pancreas. One patient had lymph node metastases, one patient had portal venous invasion and 8 patients had perineural invasion. The patient follow-up ranged from 4 to 118 months, and 32 patients were alive and well without recurrence. One patient relapsed 10 months after distal pancreatectomy with splenectomy and underwent a second surgery via laparotomy. Unfortunately, the patient died of multiple organ failure 12 days after the second surgery.

CONCLUSION

SPNs are rare neoplasms with malignant potential but excellent prognosis. Adequate surgical resection, including laparoscopic surgery, may therefore be performed safely and is associated with a long-term survival, even in invasive cases.

Successful selective internal radiotherapy (SIRT) in a patient with a malignant solid pseudopapillary pancreatic neoplasm (SPN)

Solid pseudopapillary neoplasms of the pancreas (SPNs, Gruber-Frantz-Tumor) are a rare entity representing 1-5% of all exocrine pancreatic tumors. The pseudocystic lesions preferentially affect young females <30 years, are mostly benign (∼90%) and normally present with unspecific symptoms. We describe the case of a 16-years-old Asian woman that was initially diagnosed with an SPN in the pancreatic head with mesenterial and hepatic metastases. After diagnosis, an extensive tumor resection was performed including pyloric-preserving pancreatic head resection followed by sequential resection of all hepatic metastases. After the patient was diagnosed with a hepatic recurrence and high intrahepatic tumor load, we chose a multimodal procedure and performed a selective internal radiotherapy (SIRT). Four years after SIRT and 10 years after initial diagnosis of metastatic SPN, the patient is in a good condition without any evidence for hepatic recurrence. This case represents a rare clinical course of a malignant and invasive SPN with an exceptionally long survival despite of high initial tumor burden. The selective internal radiotherapy is a suitable approach for inducing long-term remissions of the strongly vascularized liver metastases.

Solid pseudopapillary tumor of the pancreas: a single-institution 20-year series of pediatric patients

PURPOSE

Solid pseudopapillary tumor (SPT) of the pancreas is a rare neoplasm. The objective of this study was to review our institution's experience and provide an update on current management in the pediatric population.

METHODS

Our pathology database identified all patients with SPT for a 20-year period (1991-2011). Demographics, clinical characteristics, operative details, pathology, and outcomes data were retrospectively reviewed.

RESULTS

Eleven patients with SPT were identified. Most were female and Hispanic. Median age at resection was 14 years (9-17 years). Most patients presented with abdominal pain. Diagnostic imaging was most commonly an ultrasound or computed tomography. All tumors were resected en bloc. Median greatest tumor diameter was 5 cm (3.5-12 cm). Median length of stay was 8 days (5-19 days). Complications included pancreatic leak, chyle leak, delayed gastric emptying, fat malabsorption, and incisional keloid. Recurrence developed after 2.5 years in 1 patient with positive surgical margins. There were no metastases or deaths. Median follow-up was 1.4 years (0.6-5.9 years).

CONCLUSION

This pediatric series of SPT from a single institution corroborates previous reports in the literature. In our experience, SPT behaves like a low-grade malignancy and has an excellent prognosis. Surgical resection is dictated by tumor location and remains the treatment of choice.

Hepatoid carcinoma of the pancreas penetrating into the gastric cavity: a case report and literature review

A 79-year-old Japanese woman was admitted to our hospital for treatment of a pancreatic tumor measuring approximately 7 × 5 cm. The tumor had invaded the left adrenal gland and gastric wall and had penetrated into the gastric cavity. Surgical resection was performed. The tumor was composed of a brown to whitish solid area and a zone of hemorrhage, necrosis, and cystic degeneration resembling the gross features of solid pseudopapillary tumor (SPT). Histologically, the tumor showed a heterogeneous growth pattern with a combination of seat-like, trabecular, papillary and hemorrhagic-necrotic areas in various proportions. The differential diagnoses first considered were acinar cell carcinoma, neuroendocrine carcinoma and SPT with malignant transformation. Immunohistochemistry showed tumor cells were negative for pancreatic exocrine enzymes and endocrine markers. Tumor cells diffusely expressed cytokeratin 19, alpha-fetoprotein, carcinoembryonic antigen and glypican-3, but lacked vimentin or β-catenin expression. Small proportions of tumor cells expressed hepatocyte paraffin-1. Although typical morphological features of well-differentiated hepatocellular carcinoma (HCC) were not distinctly apparent, the tumor morphology partly resembled poorly differentiated HCC. Given these findings and considerations, the tumor was finally diagnosed as poorly differentiated hepatoid carcinoma of the pancreas.