Expression of Wnt target genes in solid pseudopapillary tumor of the pancreas: a pilot study

Massive extrapancreatic solid pseudopapillary neoplasm misdiagnosed as hepatic tumor: a case report and literature review

Background

Solid pseudopapillary neoplasms (SPNs) of the pancreas are uncommon, low-malignancy neoplasms. Moreover, the occurrence of extrapancreatic SPNs is rarely encountered.

Case summary

A 45-year-old female presented with a right upper abdominal mass and abdominal pain for 3 and 1 months as chief complaints, respectively. Initially, the patient was misdiagnosed with hepatocellular carcinoma based on her symptoms and results of physical and imaging examinations. Following multidisciplinary discussion and ruling out surgical contraindications, a decision was taken to proceed with surgical intervention. Interestingly, the tumor was found to originate from the retroperitoneum and had invaded the right half of the liver and the right wall of the inferior vena cava. The operation was uneventful, and the pathological findings confirmed the tumor as an extrapancreatic SPN. The patient remained asymptomatic after 15 months of follow-up.

Conclusion

Surgical treatment remains the preferred option for extrapancreatic SPN. The preoperative misdiagnosis also highlights the importance of accurate diagnosis and the development of appropriate treatment strategies for liver masses.

Evaluation of expression of the Wnt signaling components in canine mammary tumors via RT2 Profiler PCR Array and immunochemistry assays

The Wnt signaling pathway and its key component β-catenin have critical roles in the development of diseases such as tumors in mammals. However, little has been reported about involvement of the Wnt/β-catenin signaling pathway in canine mammary tumors (CMTs). The present study detected expression of 30 Wnt signaling pathway-related genes in CMTs; the results are potentially useful for molecular-based diagnosis of CMTs and the development of new targeted therapies. Significant upregulations of dickkopf-1 protein, secreted frizzled-related sequence protein 1 (SFRP1), frizzled 3, β-catenin, and lymphoid enhancer-binding factor 1 (LEF1) were detected in highly malignant CMTs compared to levels in normal mammary gland tissues; moreover, highly significant upregulation of WNT5A was observed in low malignancy CMTs. Downregulation was only detected for SFRP4 in malignant CMT samples. The subcellular location of β-catenin and cyclin D1 in 100 CMT samples was investigated via immunohistochemical analysis, and significantly increased expressions of β-catenin in cytoplasm and cyclin D1 in nuclei were revealed. Western blotting analysis revealed that the expression of β-catenin and LEF1 increased in in the majority of CMT samples. Taken together, the results provide important evidence of the activation status of the Wnt pathway in CMTs and valuable clues to identifying biomarkers for molecular-based diagnosis of CMT.

Metabolic characteristics of solid pseudopapillary neoplasms of the pancreas: their relationships with high intensity 18F-FDG PET images

Objective

We aimed to investigate the metabolic characteristics of Solid pseudopapillary neoplasms (SPNs) in relation signal intensities on ¹⁸F-FDG PET scans.

Summary Background Data

SPNs of the pancreas commonly show high uptake of 18F-FDG. However, the metabolic characteristics underlying the high ¹⁸F-FDG uptake in SPNs are not well characterized.

Materials and Methods

mRNA expressions for glucose metabolism were analyzed in five SPNs, five pancreatic ductal adenocarcinomas (PCAs), and paired normal pancreatic tissues. Among the proteins involved in glucose metabolism, the expressions of five proteins (GLUT1, HK1, PFKM, ENO2, and PKM2) were evaluated in 36 SPNs by immunohistochemistry. Clinical patterns of SPN on PET scans were classified according to the proportion of ¹⁸F-FDG uptake within the whole tumor volume (hot: ≥ 70%, mixed: 30 ≤ < 70, and defective: < 30%). PET-based parameters, including maximum standardized uptake value (SUV_max) and metabolic tumor volume (TMV_2.5), were evaluated.

Results

Hot (n = 19), mixed (n = 5), and defective (n = 12) ¹⁸F-FDG uptake patterns were noted in the 36 patients. Radiologic tumor size and SUV_max differed significantly according to these patterns (ANOVA, p < 0.05). GLUT1, HK1, PFKM, ENO2, and PKM2 were highly expressed in SPNs at both the mRNA and protein levels. Defective type SPNs showed lower expression of HK1 (p = 0.014), PKM2 (p = 0.028), and Ki-67 (p = 0.070) with frequent intra-tumoral necrosis (p = 0.007). High Ki-67 expression (≥ 3%) was associated with high SUV_max in pancreatic SPNs (p = 0.002).

Conclusions

SPN cells harbor an active molecular capacity for increased glucose metabolism. Especially, defective type SPNs were associated with low metabolic activity and related to low Ki-67 index.

Bioinformatics analysis of transcription profiling of solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasm (SPN) of the pancreas is a low-grade malignant neoplasm that accounts for ~5% of cystic pancreatic tumors and ~0.9–2.7% of exocrine pancreatic tumors. The transcription profiling data (GSE43795) of 14 SPN and 6 control samples were downloaded from the Gene Expression Omnibus (GEO) database. Using the Limma package, Student's t-tests were performed to identify differentially expressed genes (DEGs) between SPN and control samples [with the following criterion: False discovery rate (FDR)<0.01 and log₂ fold-change (FC)≥3]. Pathway and functional enrichment analyses were performed to investigate the biological processes that the DEGs were involved in. Protein-protein interaction (PPI) network and sub-network analyses were conducted to comprehensively understand the interactions between DEGs. The screened DEGs were further annotated according to information relating to transcription factors and tumor associated genes (TAGs). A total of 710 upregulated and 710 downregulated DEGs were observed, including 74 transcriptional factors and 124 TAGs. Membrane metallo-endopeptidase (MME), matrix metalloproteinase (MMP)-2 and MMP-9 were also identified as key TAGs. Following PPI network analysis, hub nodes of epidermal growth factor receptor (EGFR), proto-oncogene tyrosine protein kinase Fyn (FYN), c-JUN (JUN), glucagon (GCG), c-Myc (MYC) and CD44 were identified, the majority of which participate in the epidermal growth factor receptor (ErbB) and gonadotropin-releasing hormone (GnRH) signaling pathways. A sub-network involving 70 gene nodes was also identified, with EGFR as the central gene. MME, MMP-2 and MMP-9 contribute to proliferative diabetic retinopathy and also involved in SPN. The genes EGFR, FYN, JUN, GCG, MYC and CD44 may therefore be key genes in SPN, and the ErbB and GnRH signaling pathways may be an important contributor to SPN progression.

Recurrence of Solid Pseudopapillary Neoplasms of the Pancreas: Results of a Nationwide Study of Risk Factors and Treatment Modalities

BACKGROUND

Solid pseudopapillary neoplasms of the pancreas (SPPN) can relapse very late, but little is known about risk factors for recurrence and optimal treatment. We aimed to identify risk factors for recurrence and to analyze treatment modalities in all French pediatric cases of SPPN over the past 20 years.

MATERIAL AND METHODS

Data were collected from pediatric oncologists and surgeons, and also from adult pancreatic surgeons in order to identify late recurrences.

RESULTS

Fifty-one patients (41 girls) were identified. Median age at diagnosis was 13.1 years [8.7-17.9]. Abdominal pain was the commonest presenting symptom (32/49, 65%). The tumor was located in the pancreatic head in 24 patients (47%). Preoperative biopsy or cytology was performed in 14 cases (28%). All patients were operated with a median of 23 days [0-163] after diagnosis. The rate of postoperative morbidity was 29%. With a median follow-up of 65 months [0.3-221], the overall and event-free survival was 100% and 71%, respectively. Seven patients (13.7%) relapsed with a median of 43 months [33-94] after initial surgery. Six were treated surgically, either alone (n = 3) or with perioperative chemotherapy (n = 2) or hyperthermic intraperitoneal chemotherapy (n = 1). One patient in whom further treatment was not feasible was still alive at last news. Risk factors for recurrence were positive surgical margins (P = 0.03) and age less than 13.5 years at diagnosis (P = 0.03).

CONCLUSIONS

SPPN recurrence in this pediatric series was a rare and late event that did not undermine overall survival. Complete surgical removal of recurrent tumors appears to be the best option.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical correlations with (18)FDG PET scan patterns in solid pseudopapillary tumors of the pancreas: still a surgical enigma?

BACKGROUND

There are limited numbers of PET studies of solid pseudopapillary tumors (SPT) of the pancreas.

MATERIALS AND METHODS

We reviewed the medical records of 37 patients who underwent resection of pancreatic SPT and had been preoperatively evaluated by (18)F-FDG PET or PET/CT scan. Immunohistochemical analysis of glucose transporter-1 (GLUT-1) and hexokinase II (HK-II) was performed.

RESULTS

SPT could be categorized into five types according to the morphologic characteristics observed in PET images. Type I (hot FDG uptake in the entire tumor portion) was the most frequent (13, 34.2%), followed by type IV (focal uptake, 12, 31.6%), II (focal defect, 8, 21.1%), III (multiple and geographic uptake, 3, 7.9%), and V (total defective type, 1, 2.6%). The SUVmax in the solid portion of the SPT was 5.3 ± 4.1. The clinical pattern of FDG uptake in SPT was not associated with histopathologic features suggesting malignant potential. The SUVmax of SPT followed a pattern according to pattern of FDG uptake (R(2) = 0.203, p = 0.055), and was significantly associated with adjusted tumor volume (p = 0.001). GLUT-1 was not expressed in SPT, and only eight patients (12.3%) showed mild to moderate expression of HK-II, which was associated with the clinical pattern of SPT in PET images (p < 0.05).

CONCLUSION

SPT of the pancreas could be categorized according to the morphologic patterns observed in PET images. The clinical significance of FDG uptake, glucose metabolism, and clinical usefulness of PET scan in SPT need to be further investigated, and thus this tumor remains a surgical enigma.

The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness

Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia.

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.

Peritoneal and nodal recurrence 7 years after the excision of a ruptured solid pseudopapillary neoplasm of the pancreas: report of a case

A solid pseudopapillary neoplasm (SPN) of the pancreas is generally regarded as a neoplasm of low malignant potential and there is rarely recurrence of the disease. A 12-year-old female underwent a pylorus preserving pancreaticoduodenectomy for a ruptured pancreatic SPN following a blunt abdominal trauma. The tumor showed no pathological features suggesting malignant potential. Follow-up imaging studies depicted small nodules adjacent to the superior mesenteric vein 7 years after surgery. A laparotomy was performed, and exploration revealed 3 nodules adjacent to the superior mesenteric vein and 4 small nodules in the mesointestine. All of these lesions were extirpated, and were histologically confirmed to be nodal and peritoneal recurrence of SPN. This case indicates that SPN of the pancreas has a latent ability to recur, regardless of its benign pathological features, and peritoneal spread may be promoted by trauma. A close postoperative follow-up is thus mandatory in all patients with SPN even after a radical resection.

Solid-pseudopapillary tumor of the pancreas: clinical features, pathological characteristics, and origin

OBJECTIVE

[corrected] To study clinically pathological features and origin of solid-pseudopapillary tumor of pancreas (SPT).

PATIENTS AND METHODS

Clinical and pathological data of 82 cases with SPT were retrospectively studied. SAS6.12 statistics package was used for analysis. P < 0.05 was regarded as statistically significant difference.

RESULTS

The SPT patients included 70 females and 12 males, with a median age of 31 years old. The mean tumor size was 6.71 ± 4.42 cm. Vascular or organs was invaded in nine cases. The clinical and pathological characteristics show no significant difference between male and female patients. In the non-encapsulate group (22 cases), the tumor was larger (P = 0.0015), exogenous growth pattern (P = 0.0194), and would probably involve major vascular or organs (P = 1.697E-06). The typical features of SPT include pseudopapillary pattern with fibro vascular stalks by uniform poorly cohesive polygonal cells. The tumor cell expresses a variety of immune markers in heterogeneity. Under electron microscope, there are some electron dense granules, about 8-1.2 µm in diameter, with membrane similar to the zymogen granules in SPT cell cytoplasm.

CONCLUSIONS

SPT with incomplete capsule often presents malignant behaviors. SPT shows multi-heterogeneity, which is caused by the disorder in the development of pancreatic stem cell.

Solid pseudopapillary tumor of the pancreas: can malignancy be predicted?

BACKGROUND

The objective of this study was to examine the clinicopathologic characteristics of solid pseudopapillary tumors (SPTs) of the pancreas, including the risk factors for disease recurrence and their effects on survival.

METHODS

The medical records of 114 patients who underwent surgery for a pathologically confirmed SPT between January 1995 and December 2007 were reviewed retrospectively.

RESULTS

Of the 114 patients, 98 (86.9%) were female, and the median age was 36 years (range, 11-75). All 114 patients underwent curative intent surgery and 13 (11.4%) underwent laparoscopic surgery. Of the 114 patients, 26 (22.8%) had solid pseudopapillary carcinoma (SPC). There were no differences in any clinical factors between the benign SPT and SPC groups; however, the only 4 recurrences identified were in the SPC group. After follow-up ranging from 11 to 177 months, all 114 patients were alive, with only 4 showing evidence of recurrence. Recurrence was observed in young patients with metastasis at first operation, invasion of an adjacent organ, and a large mass (≥13 cm).

CONCLUSION

Adequate operative resection including laparoscopic surgery is the mainstay of treatment for SPT. Although statistically significant risk factors for recurrence cannot be determined, tumor metastasis at the first operation, invasion of adjacent organ, large tumor size, young patient age, tumor rupture, and inadequate resection may increase the risk of recurrence. Our results demonstrate that long-term survival could be achieved by aggressive operative resection and interventional treatment of recurrent disease.