Revision 2: an immunohistochemical approach and evaluation of solid pseudopapillary tumour of the pancreas

Primary Solid Pseudopapillary Tumor of the Ovary: A Case Report and Review of the Literature

INTRODUCTION

Solid pseudopapillary neoplasms (SPNs) are rare and mainly originate from the pancreas. SPNs originating from the ovary (SPN-O) are extremely rare, and only 13 cases have been reported in the English literature since 2010.

CASE

We report a 31-year-old woman with SPN-O accompanied by multiple metastases in the abdominal cavity. The patient underwent staging surgery and cytoreduction. Furthermore, the multidisciplinary board decided on adjuvant chemotherapy with an FP regimen (fluorouracil plus cisplatin) because a microscopic metastasis was discovered in the peritoneum near the appendix. Next-generation sequencing showed some pathologic mutations of oncogenes/cancer-associated genes, including CTNNB1 and TP53. This is the fourteenth case of SPN-O and the first one to demonstrate the TP53 pathogenic mutant variant in SPN-O. The patient showed 8 months of disease-free survival until February 2024.

CONCLUSION

The combination of R0 cytoreduction with FOLFIRI chemotherapy appears to be an effective and feasible treatment option.

Twenty-one years of experience with resected solid pseudopapillary neoplasm: a retrospective single-institutional cohort study

BACKGROUND

Although the incidence of solid pseudopapillary neoplasm (SPN) is <2% of the incidence of pancreatic tumor, the prevalence seems to be increasing. SPNs are mostly benign. However, they also show malignant features. This study aimed to identify the clinical outcomes of patients who underwent surgery for SPN at a single center.

METHODS

Data on 217 patients with SPN who underwent surgery in Samsung Medical Center between 2000 and 2020 were retrospectively analyzed.

RESULTS

Herein, the mean age of the 217 patients was 40.0 ± 12.6 years, with a female predominance (80.6%). Most patients had no comorbidity. The mean tumor size was 4.4 ± 3.1 cm. The tumor was located at the pancreatic head in 36 patients (16.6%), the body of the pancreas in 69 patients (31.8%), and the pancreatic tail in 96 patients (44.2%). Of note, 35 patients (16.1%) underwent pancreaticoduodenectomies, 148 patients (68.2%) had distal pancreatectomies, and the other patients had subtotal /total pancreatectomy (9.7%) or enucleation/mass excision (6.0%). No patient had lymph node (LN) metastasis. Moreover, 6 patients (2.8%) had a recurrence in the liver or regional LNs. The 5-year recurrence-free survival rate was 96.8%. The only factor affecting recurrence was tumor size (P = .007).

CONCLUSION

Because SPN predominates in relatively young women, patients often hesitate to undergo surgery. Nevertheless, as size is the prognostic factor, early resection is recommended for a better prognosis in the case of surgically feasible, young age, and healthy patients.

Solid pseudopapillary neoplasm of the pancreas: a retrospective study of 195 cases

Objective

Solid pseudopapillary neoplasm of the pancreas (SPN) is a rare exocrine tumor of the pancreas. The aim of our study is to summarize the clinical features of SPN and to analyze the risk factors for malignant SPN.

Methods

From May 2013 to September 2022, patients who were pathologically confirmed to have SPN were retrospectively reviewed. Demographic data, clinical and pathological features, follow-up data were collected and analyzed. To investigate the factors influencing the benign or malignant nature of SPN, we employed logistic regression. Additionally, we utilized Kaplan-Meier curves to depict and analyze the overall prognosis.

Results

A total of 195 patients were included, 163 of whom were female and the average age of all patients was 31.7 years old. Among 195 patients, 101 patients (51.8%) had no obvious clinical symptoms and their pancreatic lesions were detected during routine examination. The primary symptom was abdominal pain and distension in 64 cases (32.8%). The maximum diameter of SPN tumors ranged from 1-17 cm (mean 6.19 cm). Forty-eight postoperative complications developed in 43 (22.1%) patients. After a median follow-up duration of 44.5 months, the overall 5-year survival rate was 98.8% and the recurrence rate was 1.5%. Furthermore, we observed a statistically significant difference in the completeness of the tumor capsule between benign and malignant SPN.

Conclusion

SPN is associated with a favorable long-term survival after surgery in our large sample size cohort. For malignant SPN, tumor capsule incompleteness is an independent risk factor.

The diagnosis and management of solid pseudopapillary epithelial neoplasm of the pancreas in a resource-limited setting: two cases from Cameroon

Solid pseudopapillary epithelial neoplasm (SPEN) of the pancreas is a rare tumor of low malignant potential that occurs most often in young females. Imaging and histopathology are necessary to confirm the diagnosis as most have no symptoms. Lack of access to these technologies in sub-Saharan Africa contributes to the difficulty in making an early and accurate diagnosis, and hence, impedes treatment. We present two cases of SPEN of the pancreas in young female patients at a rural, teaching hospital in Cameroon. The diagnosis was made only with histopathology. Computed tomography scan with intravenous contrast was essential to planning a safe surgical resection. Both patients had complete surgical resection with good results.

Surveillance of Pancreatic Cystic Neoplasms

Pancreatic cystic neoplasms (PCNs) are increasingly detected because of the widespread use of cross-sectional imaging and overall aging population. While the majority of these cysts are benign, some can progress to advanced neoplasia (defined as high-grade dysplasia and invasive cancer). As the only widely accepted treatment for PCNs with advanced neoplasia is surgical resection, accurate preoperative diagnosis, and stratification of malignant potential for deciding about surgery, surveillance or doing nothing remains a clinical challenge. Surveillance strategies for pancreatic cysts (PCNs) combine clinical evaluation and imaging to assess changes in cyst morphology and symptoms that may indicate advanced neoplasia. PCN surveillance heavily relies on various consensus clinical guidelines that focus on high-risk morphology, surgical indications, and surveillance intervals and modalities. This review will focus on current concepts in the surveillance of newly diagnosed PCNs, especially on low-risk presumed intraductal papillary mucinous neoplasms (those without worrisome features and high-risk stigmata), and appraise current clinical surveillance guidelines.

Solid Pseudopapillary Neoplasm of the Pancreas: Unraveling Insights from a Single Institutional Study Emphasizing Preoperative Diagnosis of a Rare Tumor

Aim

Solid pseudopapillary neoplasm (SPN), a slow-growing pancreatic tumor with a vague clinical presentation and non-specific radiological features, is rather uncommon. We share our experience emphasizing on preoperative diagnosis and the correlation with final histopathological examination.

Materials and methods

This is a retrospective analysis of the 468 patients who underwent pancreas-related surgery at our institution between January 2013 and July 2022. Demographic characteristics, symptoms at presentation, preoperative serum calcium carbohydrate antigen (CA 19-9), lesion characteristics on cross-sectional diagnostic imaging, surgical technique, complications in postoperative period, length of stay, histopathological features, and 3-year follow-up findings of the patients with SPN of pancreas were evaluated.

Results

The male-to-female ratio was 1:11 and the mean age at presentation was 33.3 ± 9.5 years. Upper abdomen discomfort was the most common presenting complaint (91%). And five patients had findings suggestive of SPN on preoperative CECT abdomen, and the remaining six individuals were diagnosed solely based on final histological examination. The tumor's median diameter was 5.6 cm (range, 4.1-7.9). The distal body and tail of pancreas was the most common location (63%), followed by the head (36%), and was managed with distal pancreatectomy with or without spleen preservation and Whipple's procedure, respectively. One patient developed grade III Clavien-Dindo complication. The average length of in-hospital stay was 8.27±2.72 days. None of the patients had recurrence on follow-up.

Conclusion

Solid pseudopapillary neoplasm of the pancreas is often misdiagnosed preoperatively. Endoscopic ultrasound-guided FNA with IHC will be beneficial to diagnose it preoperatively especially in small-sized tumors with atypical features. Complete surgical resection with adequate margins without routine lymphadenectomy is curative in resectable tumors.

How to cite this article

Jayapal L, Kumar SR, Jebakumar GS, et al. Solid Pseudopapillary Neoplasm of the Pancreas: Unraveling Insights from a Single Institutional Study Emphasizing Preoperative Diagnosis of a Rare Tumor. Euroasian J Hepato-Gastroenterol 2023;13(2):50-54.

Solid Pseudopapillary Epithelial Neoplasm of the Pancreas: A Rare Entity with Diagnostic Dilemma

The solid pseudopapillary epithelial neoplasm (SPEN) of the pancreas is a relatively uncommon entity. The aim of the present study was to summarize our experiences with regard to diagnostic dilemma, surgery, postoperative follow-up, and management. This retrospective data were collected during the period from January 1, 2018 to December 31, 2020. A total of four patients (three females and one male) were identified within an age range of 13 to 25 years. All the patients were presented with nonspecific symptoms such as abdomen lumps, swelling in the abdomen, and abdominal pain. To reach a definite diagnosis, imaging studies were conducted along with endoscopic ultrasound fine-needle aspiration (EUS-FNA) and biopsy. After confirmation of SPEN on biopsy, all the patients underwent surgery without any complications. Patients are on follow-up, and to date, no metastasis has been detected. SPEN is a rare pancreatic tumor with unusual pathological features leading to a diagnostic dilemma. The pathologist should be familiar with SPEN and its salient histological characteristics that differentiate it from other look-alike pancreatic tumors and can help in timely surgery and management.

Solid Pseudopapillary Neoplasm - Case Series and Review of Literature

Solid-pseudopapillary neoplasm (SPN) is a variety of solid and cystic tumors of the pancreas. It was first described by Frantz in 1959. It is an unusual form of pancreatic carcinoma, with unknown etiopathogenesis, which accounts for about 0.17 to 2.7% of all pancreatic tumors. Here, we are describing 5 cases of pancreatic solid pseudopapillary neoplasm, out of 180 pancreatic tumors, operated in our institution in the 5-year period (2015-2020). Also, we have reviewed all available case series (from 2006 to 2020) in the literature, of pancreatic pseudopapillary neoplasm, for demographic information, etiopathogenesis, diagnosis, and extent of operation to establish the optimal management of this condition. Retrospective analysis of pancreatic tumors was carried out from February 2015 to January 2020. A total of 180 patients underwent pancreatic resection in this period for pancreatic tumor, out of which, the solid pseudopapillary neoplasm was confirmed in 5 cases (2.76%). Among these 5 cases, 4 cases (80%) were female and one (20%) male, with age group range from 14 to 45 years (mean age - 28 years). Abdominal pain was the most frequent presenting symptom (60%). Mean tumor diameter was 6.9 cm (range, 2-18 cm). Two patients were diagnosed preoperatively by CECT and MRI findings, and three patients were diagnosed preoperatively by percutaneous/USG-guided and CT-guided FNA cytology. Two patients underwent pancreatoduodenectomy; one patient underwent enucleation; and two patients underwent spleen preserving distal pancreatectomy. Four patients are alive and on regular follow-up, while one patient died on the 5th post-operative day due to post-operative sepsis.

One size does not fit all for pancreatic cancers: A review on rare histologies and therapeutic approaches

Exocrine pancreatic neoplasms represent up to 95% of pancreatic cancers (PCs) and are widely recognized among the most lethal solid cancers, with a very poor 5-year survival rate of 5%-10%. The remaining < 5% of PCs are neuroendocrine tumors that are usually characterized by a better prognosis, with a median overall survival of 3.6 years. The most common type of PC is pancreatic ductal adenocarcinoma (PDAC), which accounts for roughly 85% of all exocrine PCs. However up to 10% of exocrine PCs have rare histotypes, which are still poorly understood. These subtypes can be distinguished from PDAC in terms of pathology, imaging, clinical presentation and prognosis. Additionally, due to their rarity, any knowledge regarding these specific histotypes is mostly based on case reports and a small series of retrospective analyses. Therefore, treatment strategies are generally deduced from those used for PDAC, even if these patients are often excluded or not clearly represented in clinical trials for PDAC. For these reasons, it is essential to collect as much information as possible on the management of PC, as assimilating it with PDAC may lead to the potential mistreatment of these patients. Here, we report the most significant literature regarding the epidemiology, typical presentation, possible treatment strategies, and prognosis of the most relevant histotypes among rare PCs.

MRI Texture Analysis for Differentiating Nonfunctional Pancreatic Neuroendocrine Neoplasms From Solid Pseudopapillary Neoplasms of the Pancreas

RATIONALE AND OBJECTIVES

To evaluate the value of texture analysis on preoperative magnetic resonance imaging (MRI) for identifying nonfunctional pancreatic neuroendocrine neoplasms (NF-PNENs) and solid pseudopapillary neoplasms (SPNs).

MATERIALS AND METHODS

This retrospective study included 119 patients who underwent MRI, including T2-weighted imaging with fat-suppression, diffusion-weighted imaging (DWI), apparent diffusion coefficient, precontrast T1-weighted imaging with fat-suppression (T₁WI+fs), and dynamic contrast-enhanced (DCE)-T₁WI+fs. Raw data analysis, principal component analysis, linear discriminant analysis, and nonlinear discriminant analysis (NDA) were used to classify NF-PNENs and SPNs. The results are reported as misclassification rates. The images were simultaneously evaluated by an experienced senior radiologist without knowledge of the pathological results. The misclassification rate of the radiologist was compared to the MaZda (texture analysis software) results. Neural network classifier testing was used for validation. In addition, 30 textures for each MRI sequence were investigated.

RESULTS

The misclassification rate of NDA was lower than that of other analyses. In NDA, DWI obtained the lowest value of 7.92%, but there was no significant difference among the sequences. The misclassification rate of the radiologist (34.65%) was significantly higher than that of NDA for all sequences. The validation results were good in the arterial phase and delayed phase. In the training set, entropy and sum entropy were optimal texture features on DWI and precontrast T₁WI+fs, while the mean and percentile seemed to be the more discriminative features on DCE-T₁WI+fs.

CONCLUSION

Texture analysis can sensitively distinguish between NF-PNENs and SPNs on MRI, and percentile and mean of DCE-T₁WI+fs images were informative for differentiation of neoplasms.

Fine needle aspiration cytology with the aid of immunocytochemistry on cell-block confirms the diagnosis of solid pseudopapillary neoplasm of the pancreas

INTRODUCTION

To determine the diagnostic efficacy of fine needle aspiration cytology (FNAC) in cases of pancreatic solid pseudopapillary neoplasm (PSPN) with emphasis on the cytomorphological features and to evaluate the contribution of immunocytochemistry on FNAC cell-block (CB) in cases of PSPN.

METHODS

It is a retrospective study in which ultrasound-guided FNAC of pancreatic lesions diagnosed as PSPN between years 2009 and July 2019 were reviewed along with cytohistological correlation. Immunocytochemistry on CB was performed, wherever required.

RESULTS

A total of 16 patients with a cytological diagnosis of PSPN of the pancreas were identified. The most common cytological findings were characteristic branching pseudopapillary fragments with central thin, delicate capillaries associated with the amorphous myxoid substance, surrounded by tumour cells with mild pleomorphism. Immunocytochemistry was performed on CB of six cases. The tumour cells revealed nucleocytoplasmic positivity for β-catenin, cytoplasmic positivity for vimentin, membranocytoplasmic positivity for CD10 and nuclear positivity for progesterone receptor in all the cases, while they were negative for chromogranin, CD56, pan-cytokeratin and epithelial membrane antigen. The resected histopathological specimen was available in 10cases, and all were confirmed as PSPN.

CONCLUSION

Although PSPN has a characteristic cytomorphology, cell-block immunocytochemistry on FNA material confirms the diagnosis in problematic cases and excludes other pancreatic tumours, thus helping in appropriate management.

Surgical Resection of 78 Pancreatic Solid Pseudopapillary Tumors: a 30-Year Single Institutional Experience

BACKGROUND

Solid pseudopapillary tumors (SPTs) are rare, benign tumors of the pancreas that present as heterogeneous masses. We sought to evaluate the short- and long-term outcomes of surgical resected SPTs. Patients managed via initial surveillance were compared to those who underwent upfront resection.

METHODS

A prospectively maintained institutional database was used to identify patients who underwent surgical resection for a SPT between 1988 and 2018. Data on clinicopathological features and outcomes were collected and analyzed.

RESULTS

Seventy-eight patients underwent surgical resection for SPT during the study period. The mean age was 34.0 ± 14.6 years and a majority were female (N = 67, 85.9%) and white (N = 46, 58.9%). Thirty patients (37.9%) were diagnosed incidentally. Imaging-based presumed diagnosis was SPT in 49 patients (62.8%). A majority were located in the body or tail of the pancreas (N = 47, 60.3%), and 48 patients (61.5%) underwent a distal pancreatectomy. The median tumor size was 4.0 cm (IQR, 3.0-6.0), nodal disease was present in three patients (3.9%), and R0 resection was performed in all patients. No difference was observed in clinicopathological features and outcomes between patients who were initially managed via surveillance and those who underwent upfront resection. None of the patients under surveillance had nodal disease or metastasis at the time of resection; however, one of them developed recurrence of disease 95.1 months after resection. At a median follow-up of 36.1 months (IQR, 8.1-62.1), 77 (%) patients were alive and one patient (1.3%) had a recurrence of disease at 95.1 months after resection and subsequently died due to disease.

CONCLUSIONS

SPTs are rare pancreatic tumors that are diagnosed most frequently in young females. While a majority are benign and have an indolent course, malignant behavior has been observed. Surgical resection can result in exceptional outcomes.

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.

Clinical update on the management of pseudopapillary tumor of pancreas

Solid pseudopapillary neoplasm (SPN) is a rare tumor with malignant potential which is generally located in the tail of pancreas. The prevalence of SPN has increased with widespread use of cross sectional imaging. SPN is often misdiagnosed due to nonspecific clinical presentation and accurate diagnosis is essential for optimal management. Endoscopic ultrasound-FNA with immunohistochemistry can help in preoperative diagnosis. Surgery is the treatment of choice and a successful R0 resection is curative. Overall, SPN has a good prognosis. This review article focuses on pathogenesis, diagnosis and management of SPN.

Solid pseudopapillary neoplasm (SPN) of the testis: Comprehensive mutational analysis of 6 testicular and 8 pancreatic SPNs

BACKGROUND

Recently, we came with the theory of a possible relationship between a group of testicular and pancreatic tumors. We used one case of a pancreatic analogue solid pseudopapillary neoplasm of the testis composed partially of areas reminiscent of solid pseudopapillary neoplasm (SPN) of the pancreas and partially of structures identical to primary signet ring stromal tumor of the testis (PSRSTT) as a connecting link between these two entities. After demonstrating that PSRSTT and pancreatic analogue SPN of the testis share the same immunoprofile and genetic features characteristic for pancreatic SPN, we came to the conclusion that pancreatic analogue SPN of the testis and PSRSTT represent a morphological spectrum of a single entity and that both are related to the pancreatic SPN.

DESIGN

The aim of this study is to present a series of 6 cases of testicular tumors, which lacked the signet ring cell component and were thus morphologically very similar to the SPN of the pancreas. The goal of this study is to compare the genetic background of these testicular tumors that are obviously related to the PSRSTT/pancreatic analogue SPN of the testis with the series of 8 pancreatic SPN.

RESULTS

The mutational analysis revealed an oncogenic somatic mutation in the exon 3 of the CTNNB1 (β-catenin) gene in all analyzable (5/6) testicular and all pancreatic (8/8) tumors. The immunoprofile (positivity with β-catenin, CD10, vimentin, NSE, CD56, and negativity with inhibin, calretinin, chromogranin) was identical in all testicular and pancreatic tumors.

CONCLUSION

This study expanded the morphological spectrum of the PSRSTT/pancreatic analogue SPN of the testis by adding 6 cases without the signet ring cell component. Considering the obvious analogy of PSRSTT/pancreatic analogue SPN of the testis/SPN of the testis and their relationship to the pancreatic SPN we propose the collective term "solid pseudopapillary neoplasm of the testis" for these tumors. The mutational profile of the SPN of the testis and pancreas was the same in both groups of tumors which we consider as a final proof that SPN of the testis is identical to the SPN of the pancreas.

Solid Pseudopapillary Neoplasm of the Pancreas: Clinicopathologic Feature, Risk Factors of Malignancy, and Survival Analysis of 53 Cases from a Single Center

Introduction

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor of low malignant potential. The aim of this study was designed to evaluate the clinicopathologic feature, predictive factors of malignancy, and survival from experience of a single center.

Methods

53 consecutive patients who underwent surgery for a pathologically definitive SPN were retrospectively reviewed.

Results

A total of 53 cases included 7 male cases and 46 female cases with the median age of 35.4 years (14-67). Abdominal pain and mass were the most common clinical presentations. The radiological presentations were consistent with solid and cystic pattern in 18 cases, solid pattern in 25 cases, and cystic pattern in 10 cases. The predominant location of tumor was pancreatic body and tail. The mean size of the tumors was 6.4 cm. Aggressive en bloc resection combined with organ-preserving should be indicated whenever feasible. Follow-up information was available for 48 patients with a median follow-up time of 48 months. The 5-year disease-specific survival was 95.7%. Incomplete capsule was not only the predictive factor of malignancy but also the significant predictor of disease-specific survival.

Conclusion

Incomplete capsule may suggest a malignant SPN and a prognostic indicator of disease-specific survival. We recommend that surgeons consider a more radical resection with an incomplete capsule of tumor.

Prevalence, Diagnosis and Management of Pancreatic Cystic Neoplasms: Current Status and Future Directions

Cystic neoplasms of the pancreas are found with increasing prevalence, especially in elderly asymptomatic individuals. Although the overall risk of malignancy is very low, the presence of these pancreatic cysts is associated with a large degree of anxiety and further medical investigation due to concerns about malignancy. This review discusses the different cystic neoplasms of the pancreas and reports diagnostic strategies based on clinical features and imaging data. Surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines, is also discussed, with special reference to intraductal papillary mucinous neoplasm (IPMN; particularly the branch duct variant), which is the lesion most frequently identified incidentally. IPMN pathology, its risk for development into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk are discussed. Finally, surgical treatment, strategies for surveillance of pancreatic cysts, and possible future directions are discussed.

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 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.

E-cadherin-negative acinar cell carcinoma of the pancreas: report of a case showing a solid pseudopapillary growth pattern

E-cadherin expression patterns in acinar cell carcinomas (ACCs) of the pancreas have not been well documented. Herein, we present a hitherto undescribed case of E-cadherin-negative ACC with a solid pseudopapillary growth pattern in a 65-year-old man. We used an antibody against the extracellular domain of E-cadherin. As a further unusual status in ACC, faint β-catenin expression was observed in the cytoplasm of carcinoma cells. Morphological distinction from a solid pseudopapillary neoplasm (SPN) of the pancreas might be problematic in such a case, because of their similarities concerned with the growth pattern and E-cadherin negativity. Without nuclear accumulation of β-catenin, a diagnosis of SPN was almost excluded. Immunoreactivity for trypsin and BCL10 made an accurate diagnosis of ACC to this case. The tumor recurred 10 months post-surgery as rapidly enlarging masses in the liver, presumably indicating the aggressiveness of the E-cadherin-negative phenotype among ACCs.

β-catenin mutation in ovarian solid pseudopapillary neoplasm

Primaly solid pseudopapillary neoplasm (SPN) of the ovary is a rare tumor; recently 6 cases have been reported. Its pathogenesis, however, remains largely unclear. We report an additional case of primary ovarian SPN of an 18-year-old girl. The aim of this study is to define the difference between pancreatic and ovarian SPN by histological and molecular examination. Microscopically the tumor predominantly showed a solid pattern and focally a pseudopapillary pattern. The tumor cells showed two patterns of abundant eosinophilic cytoplasm and intracytoplasmic vacuoles. Immunohistochemistry of the tumor was positive for β-catenin (nuclear and cytoplasmic reactivity), α1-antitrypsin, vimentin, CD56, synaptophysin (focal weak), CD10. Mutation analyses revealed a point mutation, c.110C >T, in exon 3 of the the β-catenin gene (CTNNB1), which causes the replacement of serine with phenylalanine at codon 37. A Ser37 point mutation is known to be one of the oncogenic somatic mutations in pancreatic SPN and the major oncogenic β-catenin mutation. Ovarian SPN of our case was similar to pancreatic SPN histologicaly and had the same genomic characteristics. We expected that both ovarian and pancreatic SPNs shared the same oncogenesis related to Wnt/β-catenin pathway for tumorgenesis.

Protein mislocalization: mechanisms, functions and clinical applications in cancer

The changes from normal cells to cancer cells are primarily regulated by genome instability, which foster hallmark functions of cancer through multiple mechanisms including protein mislocalization. Mislocalization of these proteins, including oncoproteins, tumor suppressors, and other cancer-related proteins, can interfere with normal cellular function and cooperatively drive tumor development and metastasis. This review describes the cancer-related effects of protein subcellular mislocalization, the related mislocalization mechanisms, and the potential application of this knowledge to cancer diagnosis, prognosis, and therapy.

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.

Cystic and ductal tumors of the pancreas: diagnosis and management

Incidentally discovered cystic tumors of the pancreas (CTP) are an increasingly frequent entity. It is essential to differentiate lesions whose malignant potential is either nil or negligible (pseudocyst, serous cystadenoma, simple cysts) from lesions with intermediate malignant potential (intraductal papillary mucinous tumor of the pancreas [IPMN] involving the secondary ducts, cystic endocrine tumor) or those with high malignant potential (mucinous cystadenoma, solid pseudopapillary tumors and IPMN involving the main pancreatic duct). The approach to defining malignant potential is based on diagnostic CT scan, magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS), often complemented by EUS-guided cyst puncture for biochemical and cytological analysis of cyst fluid. Surgery for diagnostic purposes should be avoided because of its significant morbidity. For pseudocysts, simple cysts and serous cystadenomas, abstention is the general rule. Resection, preserving as much pancreatic parenchyma as possible, is the rule for IPMN involving the main pancreatic duct, mucinous cystadenomas, solid and pseudopapillary tumors, and cystic endocrine tumors. Resection is rarely indicated at the outset for IPMN involving secondary pancreatic ducts; morphologic observation is the general rule and preventive excision may be indicated secondarily. Good collaboration between surgeons, radiologists and endosonographists is necessary for optimal management of CTP.

Three female familial cases of solid pseudopapillary tumors with a protease serine 1 gene mutation

Solid pseudopapillary tumors (SPTs) are a rare pancreatic neoplastic lesion. Familial aggregation has not been reported in this disease. The objectives of this study were to report the history, clinicopathological features, and gene mutations of 3 familial cases of SPT. Three female cases of SPT presented in 1 family. Eight family relatives, 5 healthy volunteers, and 8 patients with SPT acted as controls. Histological examination and immunohistochemistry were performed on the surgical tumor specimens. Polymerase chain reaction-single-strand conformation polymorphism and gene sequencing were performed on genomic DNA extracted from blood. All 3 patients underwent surgical treatment, 2 patients died (3 months and 5 months after surgery), whereas neither recurrence nor metastasis was observed in the other patient during 2-year follow-up. The tumors from the 3 cases had identical immunoreactivity to a series of molecular markers. A Leu104Val mutation of protease serine 1 (PRSS1) was observed in the familial patients and 2 healthy male family members; no β-catenin or adenomatous polyposis coli mutations were detected in the familial cases. This study indicates the possibility of genetic involvement in the pathogenesis of SPT. Family history may be a positive predictive factor for malignancy in SPT.

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.

Pathology and Genetics of Pancreatic Neoplasms

This is a state-of-the-art review of the molecular genetics of pancreatic neoplasms. Although understanding of the molecular features underlying pancreatic neoplasms is still in its infancy, a strong emphasis on the relevance of these findings for the practicing surgical pathologist is provided. The application of molecular techniques has yielded a wealth of information that may soon enhance diagnostics, and will also lead to the development of safer, more effective targeted therapies. The pathologist will play a key role in integrating the current pathologic classification system with newly validated molecular markers.

Management of a malignant case of solid pseudopapillary tumor of pancreas: a case report and literature review

Solid pseudopapillary tumor of the pancreas is a rare neoplasm with low malignant potential, which affects predominantly young females. Only approximately 10% to 15% cases of solid pseudopapillary tumors (SPTs) are malignant. We present the case of a 57-year-old woman who developed malignant SPT of the pancreas. Meanwhile, a literature review was carried out. Some clinicopathological features and strategies of management of malignant SPT are presented. In general, surgical removal of the tumor even in case of metastases or recurrence offers an excellent prognosis. Chemotherapy and radiotherapy should be taken into consideration in patients with unresectable tumor.

[Pseudopapillary solid tumor of the pancreas: report of 6 cases]

BACKGROUND AND OBJECTIVES

Solid pseudopapillary neoplasms (SPNs) are rare tumours of the exocrine pancreas. Although they can develop metastasis, the prognosis is good. The aim of this study was to describe the characteristics of these tumours attended in our hospital.

PATIENTS AND METHOD

All cases of SPN in the database of the Pathology Department between 1991 and 2010 were included. Age, sex, symptoms, type of surgery, pathologic and immunohistochemical characteristics, and clinical evolution were analyzed.

RESULTS

Six cases were identified; all of them were women with a median age of 27.5 years. One patient presented haemoperitoneum, 2 abdominal pain and 3 were diagnosed incidentally. The most frequent localization was the pancreatic tail (n=4) and the median size was 7.7 cm. Four tumours were benign and 2 carcinomas. One of them had liver and lymph node metastases. Ki-67 proliferation index was low (1-3%). After a median follow-up of 33.5 months, all patients were alive and without evidence of relapse.

CONCLUSION

SPNs occur in young women. In most cases surgical resection is curative. A low mitotic index confers a good prognosis and a long survival.

Clinicopathological analysis of β-catenin and Axin-1 in solid pseudopapillary neoplasms of the pancreas

BACKGROUND

Solid pseudopapillary neoplasm (SPN) is a distinct pancreatic neoplasm and has characteristic, aberrant nuclear expression of β-catenin in most cases. However, alterations in components of the Wnt pathway, other than the β-catenin (CTNNB1) gene mutation, have not been identified. In this study, we investigated the status of Axin-1, the spectrum of mutations in the CTNNB1 gene, and the clinicopathological features of SPNs.

MATERIALS AND METHODS

We collected 27 SPNs from 25 patients. A tissue microarray was constructed to perform immunohistochemistry for β-catenin, E-cadherin, and Axin-1. The CTNNB1 and AXIN1 gene mutations were analyzed by DNA sequencing. Finally, the clinicopathological features of SPNs were analyzed for association with the CTNNB1 mutations and the Axin-1 alterations.

RESULTS

All 27 SPNs expressed nuclear immunoreactivity of β-catenin and exhibited a lack of membranous decoration of E-cadherin. All SPNs harbored CTNNB1 gene mutations. No alterations were present in the AXIN1 gene, and the immunohistochemical analysis revealed weak or absent reactivity of Axin-1 in the cytosol. All cases with a codon-37 CTNNB1 mutation had weak Axin-1 immunoreactivity in the cytoplasm (P = 0.018). No other significant correlation was found between clinicopathological parameters, CTNNB1 mutations, and Axin-1 alterations.

CONCLUSIONS

Nuclear β-catenin immunoexpression is characteristic for SPNs and corresponds to the CTNNB1 mutation. The Wnt pathway is involved in the tumorigenesis of SPNs, primarily through the alteration of β-catenin. Despite the absence of any identifiable genetic mutation, a low level of Axin-1 in the cytoplasm might contribute to the aberrant distribution of β-catenin in SPNs.

Immunohistochemical evaluation of solid pseudopapillary tumors of the pancreas: the expression pattern of CD99 is highly unique

The aim of this study was to investigate CD99 as a new marker to characterize solid pseudopapillary tumors (SPTs), and to determine a specific panel of markers to identify the disease. We analyzed the clinicopathological characteristics and immunohistochemical features of 37 patients with SPT. All 37 tumors displayed intracytoplasmic dot-like immunoreactivity of CD99 in contrast to membranous staining in all pancreatic endocrine tumors and most of acinar cell carcinomas, along with negative immunostaining in ductal carcinomas. In addition, we observed a loss of expression of E-cadherin in all SPTs as well as in some other pancreatic tumors, and aberrant nuclear expression of β-catenin in most SPTs. Our findings demonstrated for the first time that the pattern of CD99 expression was highly specific for distinguishing SPTs from other pancreatic tumors. CD99 combined with E-cadherin/β-catenin and CD10 can be used as a relatively specific expression profile of SPTs.

Synchronous solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm of the pancreas: report of a case

Solid pseudopapillary neoplasm (SPN) of the pancreas, most commonly found in young female subjects, is a rare neoplasm with low potential for malignancy. We report an unusual case of a 66-year-old male patient who had a simultaneous malignant SPN and an intraductal papillary mucinous adenoma (IPMA) of the pancreas. The patient was admitted to our department for the evaluation of the main solid tumor with calcification and small multilocular cystic lesions apart from the main tumor in the pancreatic head. We performed pylorus-preserving pancreaticoduodenectomy to treat the calcified tumor and multilocular cystic lesions. The diagnosis of malignant SPN was confirmed on the basis of histological invasion to the adjacent structures. The separate cystic lesions were diagnosed as a branch-type IPMA. The synchronous occurrence of IPMA and SPN in the present case did not demonstrate that there were tumors maintained through the common abnormal Wnt signaling pathway by immunohistochemical study. To our knowledge, this is the first known case of synchronous SPN and IPMA of the pancreas.

Primary malignant solid pseudopapillary tumors of the gastroduodenal area

Extrapancreatic cases of solid-pseudopapillary tumor (SPT) are exceedingly rare. We report here two cases of primary tumors located in the gastroduodenal region, morphologically identical to pancreatic SPT, but particular by their immunohistochemical features and malignant evolution. Clinical charts and all available histopathological material were reviewed; complementary immunohistochemical investigations and molecular analyses were performed. The patients were a 32-year-old female, submitted to surgical resection for a tumor of the prepyloric region, and a 73-year-old male presenting with a duodenal tumor and synchronous liver metastases. In the two cases, the primary tumor and all the metastases available for study were morphologically indistinguishable from typical pancreatic SPT. However, their immunohistochemical profile was characterized by the absence of hormone receptor expression and of nuclear localization of beta-catenin and E-cadherin. In the only case in which it was feasible, molecular analysis did not identify any mutation in the CTNNB1 gene. Both tumors had a malignant behavior, with extensive metastatic dissemination. In conclusion, we report two unusual cases of extrapancreatic SPT arising in the gastroduodenal area, associated with a malignant course and an extensive metastatic dissemination.

Pancreatic solid pseudopapillary tumours - EUS FNA is the ideal tool for diagnosis

BACKGROUND

Solid pseudopapillary tumour (SPT) is a rare tumour of the pancreas with low malignant potential affecting mainly young women difficult to diagnose preoperatively. The aim of this study is to describe the endoscopic ultrasound (EUS) features and utility of EUS-guided fine needle aspiration (FNA) in diagnosing these tumours.

METHODS

A retrospective analysis of SPTs identified in a tertiary institution EUS database between April 2002 and April 2009 was performed. Medical records, imaging, EUS features, cytology and histology specimens were reviewed. Patients were followed up until April 2009.

RESULTS

Seven cases of SPTs were indentified out of 2400 EUS performed. All patients were females with a mean age of 41 years (range 22-69). The tumours were solitary with a mean diameter of 2.9 cm (range 2-4.3 cm). Five tumours were located in the body and tail of the pancreas and two in the neck. All lesions were hypoechoic, heterogenous and well circumscribed, with five having a cystic component and two having a calcified rim. FNA using a 22-gauge needle was performed in six cases with no complications. A preoperative diagnosis of SPT based on cytology was obtained in 5/6 cases (83%). Surgical resection was done in six cases with confirmation of SPT and no metastatic disease.

CONCLUSION

EUS-guided FNA is a minimally invasive, safe and reliable way of diagnosing SPT by providing characteristic cytological specimens. Definitive preoperative diagnosis leads to targeted and minimally invasive surgical resection.

Pancreatic manifestations of von Hippel-Lindau disease

Von Hippel-Lindau disease is an uncommon, multisystem, multitumor disorder that can present in sporadic form but is more commonly inherited as an autosomal-dominant disease with high penetrance. Affected patients are at increased risk for developing multiple synchronous or metachronous benign or malignant, cystic, and vascular neoplasms of various organs. The characteristic neoplasms associated with von Hippel-Lindau are hemangioblastoma of the central nervous system and retina, clear cell renal cell carcinoma, and pheochromocytoma, but other lesions are well recognized. Pancreatic lesions, both primary and metastatic, are common, and several differential diagnostic possibilities must be considered.

Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

AIM: To investigate differential points of solid-pseudopapillary neoplasm (SPN) of the pancreas and pancreatic endocrine tumor (PET).

METHODS: Ten cases of SPN and fourteen cases of PET were studied in this retrospective study. Clinical and pathologic features, immunostaining reactions and β-catenin gene mutations were analyzed.

RESULTS: The mean age of SPN patients was 25.6 years and these patients had no specific symptoms. The mean diameter of the tumors was 11.0 cm, 9/10 cases were cystic or a mixture of solid and cystic structures, and there was hemorrhage and necrosis on the cut surface in 8/10 (80%) cases. Characteristic pseudopapillary structure and discohesive appearance of the neoplastic cells were observed in all 10 (100%) cases. The results of immunostaining showed that nuclear expression of β-catenin and loss of E-cadherin in all the cases, was only seen in SPN. Molecular studies discovered that 9/10 (90%) cases harbored a point mutation of exon 3 in β-catenin gene. On the other hand, the mean age of PET patients was 43.1 years. Eight of 14 cases presented with symptoms caused by hypoglycemia, and the other 6 cases presented with symptoms similar to those of SPN. The mean size of the tumors was 2.9 cm, most of the tumors were solid, only 3/14 (21%) were a mixture of solid and cystic structures, and macroscopic hemorrhage and necrosis were much less common (3/14, 21%). Histologically, tumor cells were arranged in trabecular, acinar or solid patterns and demonstrated no pseudopapillary structure and discohesive appearance in all 14 (100%) cases. The results of immunostaining and mutation detection were completely different with SPN that membrane and cytoplastic expression of β-catenin without loss of E-cadherin, as well as no mutation in β-catenin gene in all the cases.

CONCLUSION: Both macroscopic and microscopic features of SPN are quite characteristic. It is not difficult to distinguish it from PET. If necessary, immunostaining of β-catenin and E-cadherin is quite helpful to make the differential diagnosis.