Identification of potential biomarkers to differentially diagnose solid pseudopapillary tumors and pancreatic malignancies via a gene regulatory network

Reduced expression of SOX11 in colorectal adenocarcinoma is associated with mucinous and signet ring cell types, poor survival, and lower ALK expression

BACKGROUND

Mucinous and signet ring cell colorectal carcinoma (m/srCRC) are challenging colorectal adenocarcinoma (CRC) types with poor prognosis. This study aimed to investigate SOX11 and ALK immunohistochemical expression in the m/srCRC group, comparing the results to those of nonmucinous CRC (nmCRC) and studying their association with different clinicopathological CRC features to better understand their significance and role. Besides, the study assesses which marker has a better predictive value for clinical practice.

METHODS

Tissue microarrays were prepared from 150 CRC blocks distributed equally between the m/srCRC and nmCRC groups. SOX11 and ALK immunohistochemical expressions were compared between both groups. In addition, their association with CRC clinicopathological data and survival was investigated. The Receiver Operating Characteristic (ROC) Curve analysis examined the predictive ability of SOX11 and ALK IHC expression for CRC mortality.

RESULTS

Both SOX11 and ALK expression were significantly reduced in m/srCRC compared to nmCRC. SOX11 is significantly associated with other prognostic clinicopathological factors (tumor size, lymph node status, overall TNM stage, grade, lymphovascular and perineural invasion) and overall survival. SOX11 significantly positively correlates with ALK expression. Using the ROC analysis, SOX11 is superior to ALK in survival prediction.

CONCLUSION

SOX11 can be used as a prognostic marker and is a suggested therapeutic target in mucinous and signet ring cell colorectal carcinoma through upregulation modulation.

[Expression and significance of INSM1 and SOX11 in pancreatic neuroendocrine tumor and solid pseudopapillary neoplasm]

OBJECTIVE

To investigate the expression and significance of insulinoma associated protein 1 (INSM1) and SRY-related high-mobility group box 11 (SOX11) in pancreatic neuroendocrine tumor (PNET) and solid pseudopapillary neoplasm (SPN).

METHODS

To detect the expression of INSM1, SOX11, Syn, CgA, CD56, β-catenin, and CD99 in 56 cases of PNET, 42 cases of SPN, 16 cases of ductal adenocarcinoma (DACC) and 8 cases of acinar cell carcinoma (ACC) by immunohistochemistry. The application value of combination of INSM1 and SOX11 was compared with conventional markers (Syn, CgA, CD56, β-catenin, and CD99) in diagnosis and differential diagnosis of PNET and SPN.

RESULTS

(1) In the 56 cases of PNET, the positive signals of INSM1 were located in the tumor and islet nucleus, the positive expression rate in the tumor tissues was 91.07% (51/56), whereas the signal was absent in 42 cases of SPN, 16 cases of DACC and 8 cases of ACC, and there were significant statistical difference between PNET with SPN, DACC, and ACC respectively (P < 0.001). (2) The positive signals of SOX11 were located in the tumor nucleus, with the positive expression rate was 92.86% (39/42) in SPN, however, the positive expression rate of SOX11 was 8.93% (5/56) in PNET, which included 3 cases of G1 and 2 cases of G3 types of PNET, the SOX11 positive signal was absent in 16 cases of DACC, 8 cases of ACC and peritumoral nomal pancreatic tissue, and the differences were statistically significant of positive rate between SPN with PNET, DACC and ACC, respectively (P < 0.001). (3) The sensitivity of INSM1(+)/SOX11(-) immunophenotype for PNET was 85.71%, vs. CD56 (57.14%), the difference was statistically significant (P=0.001); vs. Syn (80.36%) and CgA (71.43%), the difference was no statistically significant (P>0.05). The specificity of INSM1(+)/SOX11(-) for PNET was 100.00%, vs. Syn (42.86%) and CD56 (47.62%), the difference was statistically significant (P < 0.001); vs. CgA (92.86%), the difference was no statistically significant (P>0.05). The sensitivity of INSM1(-)/SOX11(+) immunophenotype for SPN was 92.86%, vs. β-catenin (90.48%) and CD99 (85.71%), the difference was no statistically significant (P>0.05). The specificity of INSM1(-)/SOX11(+) for SPN was 96.43%, vs. CD99 (48.21%), the difference was statistically significant (P < 0.001); vs. β-catenin (100.00%), the difference was no statistically significant (P>0.05). (4) The positive expression of INSM1 and SOX11 in PNET and SOX11 were not correlated with clinicopathological parameters (age, gender, tumor size, location, grade, and metastasis) (P>0.05).

CONCLUSION

The positive expression patterns of INSM1 and SOX11 in PNET and SPN respectively are conductive to distinguish the both tumors. The combination of both take precedence over some corresponding conventional immunohistochemical markers in terms of sensitivity and specificity.

Utility of SOX11 for the diagnosis of solid pseudopapillary neoplasm of the pancreas on cytological preparations

INTRODUCTION

The diagnosis of solid pseudopapillary neoplasm (SPN) on fine needle aspiration specimens can be challenging because of morphological overlap with other pancreatic neoplasms, including pancreatic neuroendocrine tumour (PanNET). SRY-related high-mobility group box 11 (SOX11) is a recently described sensitive and specific marker for SPN diagnosis. However, SOX11 immunocytochemistry on cytological smears has not been reported. We evaluated the utility of SOX11 for diagnosis of SPN on cytological preparations.

METHODS

SOX11 immunocytochemistry was performed on Papanicolaou-stained smears and/or corresponding cell blocks from aspirates of 7 SPN and 10 PanNET cases identified between 2005 and 2020. Findings were compared with those for beta-catenin, a frequently used diagnostic marker for SPN.

RESULTS

Six smears and 6 cell blocks from SPN cases and 8 smears and 10 cell blocks from PanNET cases were available for immunostaining. For SPN, nuclear staining for SOX11 was seen in 6 of 6 (100%) smears and 5 of 6 (83%) cell blocks, with equivocal staining in 1 cell block. In contrast, 7 of 8 (88%) smears and 9 of 10 (90%) cell blocks were negative for SOX11 for PanNet, with equivocal staining seen in 1 case. Beta-catenin immunocytochemistry showed nuclear staining in 6 of 7 (86%) SPN cases and no staining in all 10 (100%) PanNET cases.

CONCLUSIONS

SOX11 detected by immunocytochemistry can serve as a useful diagnostic marker for SPN, in addition to beta catenin, and can be performed on cytological smears in cases without a cell block preparation.

Case Report: Targeted Therapy for Metastatic Solid Pseudopapillary Neoplasm of the Pancreas With CTNNB1 and PTEN Mutations

Background

Solid pseudopapillary neoplasm (SPN) of the pancreas shows an indolent clinical behavior in cases undergoing surgical resection. The efficacy of combination therapy in the metastatic extrapancreatic SPN treatment remains largely unknown and a clinical challenge.

Case Presentation

We report a case of a metastatic pancreatic SPN in a 45-year-old woman who presented with an aggressive peritoneal dissemination and hepatic metastases and still showed an indolent clinical course with combination therapy with repeated surgery and targeted therapy. Although the follow-up effect remains to be seen, this is the first report of practical experience of the targeted agents sunitinib and everolimus in metastatic SPN tumors based on the mutation status of PTEN (c.379G>A; p.G127R) and CTNNB1 (c.98C>G; p.S33C). To our knowledge, the PTEN variant identified in this case has not been previously reported in SPN.

Conclusion

Evidence on variant genetics indicates that future molecular studies may not only help to explain the mechanism of SPN occurrence and development but are also more likely to direct to future precision treatments.

Identifying miRNA-mRNA Integration Set Associated With Survival Time

In the “personalized medicine” era, one of the most difficult problems is identification of combined markers from different omics platforms. Many methods have been developed to identify candidate markers for each type of omics data, but few methods facilitate the identification of multiple markers on multi-omics platforms. microRNAs (miRNAs) is well known to affect only indirectly phenotypes by regulating mRNA expression and/or protein translation. To take into account this knowledge into practice, we suggest a miRNA-mRNA integration model for survival time analysis, called mimi-surv, which accounts for the biological relationship, to identify such integrated markers more efficiently. Through simulation studies, we found that the statistical power of mimi-surv be better than other models. Application to real datasets from Seoul National University Hospital and The Cancer Genome Atlas demonstrated that mimi-surv successfully identified miRNA-mRNA integrations sets associated with progression-free survival of pancreatic ductal adenocarcinoma (PDAC) patients. Only mimi-surv found miR-96, a previously unidentified PDAC-related miRNA in these two real datasets. Furthermore, mimi-surv was shown to identify more PDAC related miRNAs than other methods because it used the known structure for miRNA-mRNA regularization. An implementation of mimi-surv is available at http://statgen.snu.ac.kr/software/mimi-surv.

Pancreatic Solid Pseudopapillary Neoplasm: Key Pathologic and Genetic Features

CONTEXT.—

Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor generally associated with a good prognosis. Solid pseudopapillary neoplasms show peculiar morphologic features, but sometimes the differential diagnosis with other pancreatic neoplasms (ie, pancreatic neuroendocrine tumors) can be a challenging task, especially in cytologic or biopsy specimens. In these cases immunohistochemistry is a useful tool, but the diagnostic utility of several proposed immunohistochemical markers is questionable. In recent years, despite several attempts to characterize the pathogenetic, molecular, and prognostic features of solid pseudopapillary neoplasms, they still remain unclear.

OBJECTIVE.—

To give the reader a comprehensive update on this entity.

DATA SOURCES.—

The PubMed database (US National Library of Medicine) was searched using the following string: pseudopapillary tumor [AND/OR] neoplasm [AND/OR] pancreas. All articles written in English were included. In addition, because a heterogeneous terminology has been used in the past to define solid pseudopapillary neoplasms, the reference lists of each paper selected in the PubMed database were also reviewed.

CONCLUSIONS.—

This review gives a comprehensive update on the pathologic, clinical, and molecular features of solid pseudopapillary neoplasms, particularly addressing issues and challenges related to diagnosis. In addition, we have tried to correlate the molecular alterations with the morphologic and clinical features.

[Diagnostic Utility of LEF1 Immunostain in Cytology Specimens of Solid Pseudopapillary Neoplasm of Pancreas]

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm. Diagnosis of SPN requires an integrated approach with aid of radiology, biopsy, cytology, and immunohistochemical stains. Although morphological features in combination with nuclear positivity of β-catenin IHC have been the gold standard of SPN diagnosis, but overlapping morphology and immunohistochemical findings with other entities in differential diagnoses such as pancreatic neuroendocrine tumors and pancreatic ductal adenocarcinoma make the diagnosis of SPN difficult particularly in limited cytology specimens. Lymphoid enhancer-binding factor 1 (LEF1), a key player in the Wnt signaling pathway, has shown promising diagnostic utility in SPN in recent literatures.

METHODS

In this retrospective study, we evaluated the diagnostic utility of LEF1 IHC in SPN in cytology specimens. LEF1 IHC was performed and compared with β-catenin, synaptophysin, and chromogranin immunostains in 13 SPN and 23 pancreatic neuroendocrine tumors (PanNETs) cytology cases with retrievable cell blocks.

RESULTS

LEF1 was positive in 13 of 13 (100%) SPNs and was negative in all PanNETs (0%).

CONCLUSION

LEF1 shows 100% sensitivity and specificity in cytology specimens for SPN and can be valuable immuno-stain in the diagnosis of SPN in cytology cell blocks.

SOX11, SOX10 and MITF Gene Interaction: A Possible Diagnostic Tool in Malignant Melanoma

Malignant melanoma (MM) is a highly heterogenic tumor whose histological diagnosis might be difficult. This study aimed to investigate the diagnostic and prognostic utility of the conventional pan-melanoma cocktail members (HMB-45, melan-A and tyrosinase), in conjunction with SOX10 and SOX11 immunohistochemical (IHC) expression. In 105 consecutive cases of MMs and 44 of naevi, the IHC examination was performed using the five-abovementioned markers, along with microphthalmia transcription factor (MITF), S100, and Ki67. Correlation with the clinicopathological factors and a long-term follow-up was also done. Survival analysis was performed with Kaplan–Meier curves and compared with TCGA public datasets. None of the 44 naevi expressed SOX11, but its positivity was seen in 52 MMs (49.52%), being directly correlated with lymphovascular invasion, the Ki67 index, and SOX10 expression. HMB-45, SOX10, and tyrosinase, but not melan-A, proved to differentiate the naevi from MMs successfully, with high specificity. Triple MITF/SOX10/SOX11 co-expression was seen in 9 out of 15 negative conventional pan-melanoma-cocktail cases. The independent prognostic value was proved for the conventional pan-melanoma cocktail (triple positivity for HMB-45, melan-A, and tyrosinase) and, independently for HMB-45 and tyrosinase, but not for melan-A, SOX10, or SOX11. As consequence, to differentiate MMs from benign naevi, melan-A should be substituted by SOX10 in the conventional cocktail. Although the conventional pan-melanoma cocktail, along with S100 can be used for the identification of melanocytic origin of tumor cells and predicting prognosis of MMs, the conventional-adapted cocktail (triple positivity for HMB-45, SOX10, and tyrosinase) has a slightly higher diagnostic specificity. SOX11 can be added to identify the aggressive MMs with risk for lymphatic dissemination and the presence of circulating tumor cells.

Blocking circ_0013912 Suppressed Cell Growth, Migration and Invasion of Pancreatic Ductal Adenocarcinoma Cells in vitro and in vivo Partially Through Sponging miR-7-5p

Background

Circular RNAs have been emerging as biomarkers in diagnosis and prognosis of pancreatic ductal adenocarcinoma (PDAC). The hsa_circ_0013912 (circ_0013912) has been retrieved to be upregulated in PDAC. Here, we further investigated its role in PDAC cells, as well as its mechanism via serving as competing endogenous RNA (ceRNA) for miRNA (miR)-7-5p, which is abundant in pancreas and suppresses the development of PDAC.

Materials and Methods

The clinical human tissues were harvested from Gene Expression Omnibus (GEO) database and PDAC patients, and expression of circ_0013912 and miR-7-5p was detected by real-time quantitative PCR. The interaction between both was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation and biotin-miRNA pull-down assay. Functional experiments were performed using Cell Counting Kit-8 assay, colony formation assay, fluorescence-activated cell separation method, caspase 3 activity assay kit, Western blotting, transwell assays, and xenograft tumor model.

Results

circ_0013912 was upregulated in PDAC tumors and cells; besides, circ_0013912 upregulation was associated with TNM stage and lymph node metastasis. Silencing circ_0013912 inhibited cell viability, colony formation ability, cell cycle entrance, migration and invasion, but facilitated apoptosis rate and caspase 3 activity in PANC-1 and AsPC-1 cells, accompanied with decreased c-myc, cyclin D1 and vimentin, and increased E-cadherin. Furthermore, miR-7-5p was a target of circ_0013912. Blocking miR-7-5p could promote cell growth, migration and invasion of PANC-1 and AsPC-1 cells with circ_0013912 silencing or not. Tumor growth was also restrained by circ_0013912 downregulation.

Conclusion

Circ_0013912 knockdown could suppress cell growth and metastasis of PDAC cells via sponging miR-7-5p.

Correlation-Centric Network (CCN) representation for microbial co-occurrence patterns: new insights for microbial ecology

Mainstream studies of microbial community focused on critical organisms and their physiology. Recent advances in large-scale metagenome analysis projects initiated new researches in the complex correlations between large microbial communities. Specifically, previous studies focused on the nodes (i.e. species) of the Species-Centric Networks (SCNs). However, little was understood about the change of correlation between network members (i.e. edges of the SCNs) when the network was disturbed. Here, we introduced a Correlation-Centric Network (CCN) to the microbial research based on the concept of edge networks. In CCN, each node represented a species-species correlation, and edge represented the species shared by two correlations. In this research, we investigated the CCNs and their corresponding SCNs on two large cohorts of microbiome. The results showed that CCNs not only retained the characteristics of SCNs, but also contained information that cannot be detected by SCNs. In addition, when the members of microbial communities were decreased (i.e. environmental disturbance), the CCNs fluctuated within a small range in terms of network connectivity. Therefore, by highlighting the important species correlations, CCNs could unveil new insights when studying not only the functions of target species, but also the stabilities of their residing microbial communities.

Molecular Diagnosis of Cystic Neoplasms of the Pancreas: a Review

BACKGROUND

The prevalence of incidental pancreatic cystic neoplasms (PCNs) has increased dramatically with advancements in cross-sectional imaging. Diagnostic imaging is limited in differentiating between benign and malignant PCNs. The aim of this review is to provide an overview of biomarkers that can be used to distinguish PCNs.

METHODS

A review of the literature on molecular diagnosis of cystic neoplasms of the pancreas was performed.

RESULTS

Pancreatic cysts can be categorized into inflammatory and non-inflammatory lesions. Inflammatory cysts include pancreatic pseudocysts. Noninflammatory lesions include both mucinous and non-mucinous lesions. Mucinous lesions include intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm. Non-mucinous lesions include serous cystadenoma and solid-pseudopapillary tumor of the pancreas. Imaging, cyst aspiration, and histologic findings, as well as carcinoembryonic antigen and amylase are commonly used to distinguish between cyst types. However, molecular techniques to detect differences in genetic mutations, protein expression, glycoproteomics, and metabolomic profiling are important developments in distinguishing between cyst types.

DISCUSSION

Nomograms incorporating common clinical, laboratory, and imaging findings have been developed in a better effort to predict malignant IPMN. The incorporation of top molecular biomarker candidates to nomograms may improve the predictive ability of current models to more accurately diagnose malignant PCNs.

Micro-RNA Expression Patterns Predict Metastatic Spread in Solid Pseudopapillary Neoplasms of the Pancreas

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Up to 10% of patients with localized disease at presentation will develop systemic metastases, usually in the peritoneum or the liver. Due to the rarity of SPNs and the overall excellent prognosis, reliable prognostic factors to predict malignant biological behavior remain undetermined. Therefore, we aimed to define clinical, histological, and microRNA patterns that are associated with metastatic disease. We conducted a retrospective single center study on all patients operated for SPN of pancreas between 1995 and 2018. Clinical and pathological data were collected, and expression patterns of 2,578 human microRNAs were analyzed using microRNA array (Affimetrix 4.1) in normal pancreases (NPs), localized tumors (LTs), and metastatic tumors (MTs). The diagnosis of SPN was confirmed in 35 patients who included 28 females and 3 males, with a mean age of 33.8 ± 13.9 years. The only clinical factor associated with metastases was tumor size (mean tumor size 5.20 ± 3.78 in LT vs. 8.13± 1.03 in MT, p < 0.012). Microscopic features of malignancy were not associated with metastases, nor were immunohistochemical stains, including the proliferative index KI67. Higher expressions of miR-184, miR-10a, and miR-887, and lower expressions of miR-375, miR-217, and miR-200c were observed in metastatic tissues on microarray, and validated by real-time polymerase chain reaction. Hierarchal clustering demonstrated that the microRNA expression pattern of MTs was significantly different from that of LTs. The only clinical factor associated with metastases of SPN of pancreas was tumor size. Histological features and immunohistological staining were not predictive of metastases. A panel of six microRNAs was differentially expressed in MTs, and these findings could potentially be used to predict tumor behavior. Validation of these results is needed in larger series.

mirTrans: a resource of transcriptional regulation on microRNAs for human cell lines

The cell-specific information of transcriptional regulation on microRNAs (miRNAs) is crucial to the precise understanding of gene regulations in various physiological and pathological processes existed in different tissues and cell types. The database, mirTrans, provides comprehensive information about cell-specific transcription of miRNAs including the transcriptional start sites (TSSs) of miRNAs, transcription factor (TF) to miRNA regulations and miRNA promoter sequences. mirTrans also maps the experimental H3K4me3 and DHS (DNase-I hypersensitive site) marks within miRNA promoters and expressed sequence tags (ESTs) within transcribed regions. The current version of database covers 35 259 TSSs and over 2.3 million TF-miRNA regulations for 1513 miRNAs in a total of 54 human cell lines. These cell lines span most of the biological systems, including circulatory system, digestive system and nervous system. Information for both the intragenic miRNAs and intergenic miRNAs is offered. Particularly, the quality of miRNA TSSs and TF-miRNA regulations is evaluated by literature curation. 23 447 TSS records and 2148 TF-miRNA regulations are supported by special experiments as a result of literature curation. EST coverage is also used to evaluate the accuracy of miRNA TSSs. Interface of mirTrans is friendly designed and convenient to make downloads (http://mcube.nju.edu.cn/jwang/lab/soft/mirtrans/ or http://120.27.239.192/mirtrans/).

SOX11: friend or foe in tumor prevention and carcinogenesis?

Sex-determining region Y-related high-mobility-group box transcription factor 11 (SOX11) is an essential member of the SOX transcription factors and has been highlighted as an important regulator in embryogenesis. SOX11 studies have only recently shifted focus from its role in embryogenesis and development to its function in disease. In particular, the role of SOX11 in carcinogenesis has become of major interest in the field. SOX11 expression is elevated in a wide variety of tumors. In many cancers, dysfunctional expression of SOX11 has been correlated with increased cancer cell survival, inhibited cell differentiation, and tumor progression through the induction of metastasis and angiogenesis. Nevertheless, in a limited number of malignancies, SOX11 has also been identified to function as a tumor suppressor. Herein, we review the correlation between the expression of SOX11 and tumor behaviors. We also summarize the mechanisms underlying the regulation of SOX11 expression and activity in pathological conditions. In particular, we focus on the pathological processes of cancer targeted by SOX11 and discuss whether SOX11 is protective or detrimental during tumor progression. Moreover, SOX11 is highlighted as a clinical biomarker for the diagnosis and prognosis of various human cancer. The information reviewed here should assist in future experimental designs and emphasize the potential of SOX11 as a therapeutic target for cancer.

TFE3 is a diagnostic marker for solid pseudopapillary neoplasms of the pancreas

Aberrant Wnt signaling is a hallmark of solid pseudopapillary neoplasms (SPNs) of the pancreas. Transcription factor E3 (TFE3) plays a critical role in activation and regulation of the Wnt pathway and is predicted to be a candidate gene implicated in SPN by gene regulatory network analysis. The aim of this study was to evaluate TFE3 as a marker for SPN. Paraffin-embedded tissues of SPN (n = 75) and other primary pancreatic tumors were analyzed, including pancreatic neuroendocrine tumors (n = 17), pancreatic ductal adenocarcinomas (n = 14), pancreatic neuroendocrine carcinomas (n = 4), and acinar cell carcinomas (n = 3). The clinicopathological features were summarized as well. Differentiation of specific pancreatic duct or acinus was not found in any SPN tissue. Morphologic and immunohistochemical results indicated that SPN displays certain characteristics of neuroendocrine cells. Overall, 71 (94.67%) cases of SPN showed nuclear accumulation for TFE3, most of which displayed moderate to intense expression. The TFE3 positive rates in pancreatic neuroendocrine tumor, pancreatic ductal adenocarcinoma, and pancreatic neuroendocrine carcinoma were 23.53%, 14.29%, and 25%, respectively. All 3 cases of acinar cell carcinoma were negative for TFE3. We conclude that SPN may originate from primordial pancreatic cells and is accompanied by some characteristics of neuroendocrine tumors. TFE3, besides β-catenin, can be an additional diagnostic marker of SPN in differential diagnosis.

Solid Pseudopapillary Neoplasms of the Pancreas: A Surgical and Genetic Enigma

Solid pseudopapillary neoplasms of the pancreas are rare tumors accounting for 1-2% of pancreatic exocrine neoplasms. This entity was first described by Dr. Frantz in 1959 and was defined by the World Health Organization in 1996 as "solid pseudopapillary tumor." It is most often a benign neoplasm, but 10-15% of the cases are malignant. Over the past decades, the incidence of this tumor is increasing. However, many surgeons are still unfamiliar with this neoplasm and its unique characteristics, which can lead to pitfalls in the diagnosis and treatment. The correct diagnosis of SPNP is of utmost importance since it has a low malignant potential and with the appropriate treatment, patients have a long life expectancy. There are many genetic alterations, involving various signaling pathways that have been associated with SPNP and are very important in diagnosing the tumor. The cornerstone of SPNP treatment includes surgical excision of the tumor, preserving as much pancreatic tissue as possible. We review the information in the literature regarding more organ-preserving techniques and possible clinical features that might indicate a malignant potential, thus demanding a more radical intraoperative excision.

Overexpression of SOX11 and TFE3 in Solid-Pseudopapillary Neoplasms of the Pancreas

OBJECTIVES

To characterize the expression of SOX11 and TFE3 proteins in solid-pseudopapillary neoplasms (SPNs) and their histologic mimickers.

METHODS

Immunohistochemistry for SOX11, TFE3, and β-catenin was performed on 31 cases of surgically resected SPNs. Neuroendocrine tumors, acinar cell carcinomas, and pancreatoblastomas served as controls.

RESULTS

Nuclear immunoreactivity for SOX11 was detected in all SPNs and five of 31 control tumors. Nuclear immunoreactivity for TFE3 was detected in 30 SPNs and three control tumors. Nuclear immunoreactivity for β-catenin was detected in all SPNs and four control tumors. The combination of three markers as immunohistochemical panels resulted in optimal sensitivity and specificity.

CONCLUSIONS

Both SOX11 and TFE3 were overexpressed in SPNs and may be involved in the pathogenesis. Clinically, SOX11 and TFE3 can be potentially used as diagnostic markers in distinguishing indeterminate SPNs from their histologic mimickers.

Immunocytochemistry for SOX-11 and TFE3 as diagnostic markers for solid pseudopapillary neoplasms of the pancreas in FNA biopsies

BACKGROUND

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare malignant tumors that can be sampled via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Although diagnosing SPNs can be straightforward in cases with a classic morphology and a typical immunoprofile, challenges can occur with morphologic variants or limited specimens. Recently, 2 immunohistochemical stains, SRY-related high-mobility group box 11 (SOX-11) and transcription factor E3 (TFE3), have been demonstrated to be highly sensitive and specific for SPNs in pancreatic resection specimens. The current study evaluates the diagnostic utility of these stains with EUS-FNA.

METHODS

Thirteen EUS-FNA specimens from SPNs with sufficient material for immunocytochemistry were identified from 2000 to 2016. These cases were compared with 13 EUS-FNA specimens of non-SPN pancreatic neoplasms. Immunocytochemistry for SOX-11, TFE3, and β-catenin was performed on all cell blocks and then was scored independently by 2 pathologists in a masked manner.

RESULTS

Nuclear reactivity for SOX-11 was detected in 13 of 13 SPNs and in 0 of 13 non-SPNs; this resulted in sensitivity and specificity values of 100%, a positive predictive value (PPV) of 1, and a negative predictive value (NPV) of 1. Nuclear reactivity for TFE3 was detected in 9 of 13 SPNs and in 0 of 13 non-SPNs; this resulted in a sensitivity of 69.2%, a specificity of 100%, a PPV of 1, and an NPV of 0.765. Nuclear reactivity for β-catenin was detected in 13 of 13 SPNs and in 1 of 13 non-SPNs; this resulted in a sensitivity of 100%, a specificity of 92.3%, a PPV of 0.929, and an NPV of 1.

CONCLUSIONS

SOX-11 is a sensitive and specific immunocytochemical stain for SPNs in EUS-FNA specimens, and it may be useful as a diagnostic marker for distinguishing SPNs from its cytologic mimics. Cancer Cytopathol 2017;125:831-7. © 2017 American Cancer Society.

LEF1, TFE3, and AR are putative diagnostic markers of solid pseudopapillary neoplasms

The diagnosis of solid pseudopapillary neoplasms (SPNs) is challenging because some SPNs share many similar morphological and immunohistochemical features with other pancreatic neoplasms. In this study, we investigated potential diagnostic markers of SPN.

Based on the SPN-specific upregulated genes from a previous DNA microarray and proteome study, we selected six immunohistochemical markers [beta-catenin, androgen receptor (AR), lymphoid enhancer-binding factor 1 (LEF1), transcription factor for immunoglobulin heavy-chain enhancer 3 (TFE3), fused in sarcoma (FUS), and WNT inhibitory factor 1 (WIF-1)]. We also evaluated the Ki-67 proliferative index to investigate its associations with prognosis. To validate these markers, we studied 91 SPNs as well as 51 pancreatic ductal carcinomas (PDC) and 48 neuroendocrine tumors (NET) as controls.

We found frequent and diffuse nuclear expressions of β-catenin (98.9%), AR (81.3%), LEF1 (93.4%), TFE3 (74.7%), FUS (84.6%), and cytoplasmic expression of WIF-1 (96.7%) in SPNs. In contrast, PDCs and NETs showed no expression. (P < 0.001). When beta-catenin, LEF1, and TFE3 staining were combined, the sensitivity and specificity were 100% and 91.9%, respectively. Four (4.4%) SPNs showed distant metastasis and these tumors were associated with a relatively high Ki-67 proliferative index (≥ 5%; P = 0.013).

We identified LEF1, TFE3, and AR as putative diagnostic markers of SPN, auxiliary to β-catenin. Incorporated into an immunohistochemical panel, these markers could be beneficial to distinguish SPN from PDC and NET. In addition, we suggest that the Ki-67 proliferative index can be a predictive marker of metastasis in SPNs.

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

OBJECTIVES

The aims of this study were to introduce our experience with treating patients with pancreatic solid pseudopapillary tumors (SPTs) and to investigate the clinical risk factors for recurrence of SPTs because no consensus has been established to date.

METHODS

One hundred twenty-one patients underwent surgical resection from January 2008 to December 2015 in our institution. Clinical data were collected from the standardized reports.

RESULTS

Of the 121 patients, 93 (76.9%) were women, 28 (23.1%) were men, and the mean age at diagnosis was 33.7 years (range, 11-68 years). Sixty patients were subjected to short-term complications, and 8 patients experienced long-term complications, some of whom may require surgery. The tumor located in the distal pancreas (P = 0.02), and a Ki-67 index value > 1.5 (P = 0.01) indicated malignancy according to the World Health Organization 2000 classification. One hundred three patients responded to follow-up, and 3 cases (2.9%) were subject to liver metastases. Recurrence was more frequently observed in tumors classified as high-grade malignancies according to the World Health Organization 2010 classification (P = 0.013), synchronous metastases (P < 0.001), peripancreatic fat infiltration (P = 0.018), and lymphovascular invasion (P < 0.001).

CONCLUSIONS

Evaluating the risk of the recurrence of SPTs still requires systematic and multicenter trials in the future, even some pathological features showed statistical differences.