DNA Methylation Profiling Enables Accurate Classification of Nonductal Primary Pancreatic Neoplasms.

BACKGROUND & AIMS: Cytologic and histopathologic diagnosis of non-ductal pancreatic neoplasms can be challenging in daily clinical practice, whereas it is crucial for therapy and prognosis. The cancer methylome is successfully used as a diagnostic tool in other cancer entities. Here, we investigate if methylation profiling can improve the diagnostic work-up of pancreatic neoplasms. METHODS: DNA methylation data were obtained for 301 primary tumors spanning 6 primary pancreatic neoplasms and 20 normal pancreas controls. Neural Network, Random Forest, and extreme gradient boosting machine learning models were trained to distinguish between tumor types. Methylation data of 29 nonpancreatic neoplasms (n = 3708) were used to develop an algorithm capable of detecting neoplasms of non-pancreatic origin. RESULTS: After benchmarking 3 state-of-the-art machine learning models, the random forest model emerged as the best classifier with 96.9% accuracy. All classifications received a probability score reflecting the confidence of the prediction. Increasing the score threshold improved the random forest classifier performance up to 100% with 87% of samples with scores surpassing the cutoff. Using a logistic regression model, detection of nonpancreatic neoplasms achieved an area under the curve of >0.99. Analysis of biopsy specimens showed concordant classification with their paired resection sample. CONCLUSIONS: Pancreatic neoplasms can be classified with high accuracy based on DNA methylation signatures. Additionally, non-pancreatic neoplasms are identified with near perfect precision. In summary, methylation profiling can serve as a valuable adjunct in the diagnosis of pancreatic neoplasms with minimal risk for misdiagnosis, even in the pre-operative setting.

Solid Pseudopapillary Tumor of the Pancreas: Is Enucleation Safe?

BACKGROUND: While solid pseudopapillary tumor (SPT) of the pancreas are oncologically low-risk tumors, their resection with pancreaticoduodenectomy (PD) or partial pancreatectomy (PP) carries a significant risk for morbidity. To balance the favorable prognosis with the surgical morbidity of pancreas resection, this study explores the oncologic safety of enucleation (EN). PATIENTS AND METHODS: The National Cancer Database (NCDB) was queried for resected SPT from January 2004 through December 2020. Perioperative outcomes and survival were analyzed with Kruskal-Wallis tests, and Kaplan-Meier analysis (with log-rank test). Survival analysis was performed to compare patients with and without lymph node (LN) metastases and binary logistic regression for predictors of LN metastasis. RESULTS: A total of 922 patients met inclusion criteria; 18 patients (2%) underwent EN, 550 (59.6%) underwent PP, and 354 (38.4%) underwent PD. Mean tumor size was 57.6 mm. Length of hospital stay was significantly shorter for EN compared with PP and PD groups (3.8 versus 6.2 versus 9.4 days, p < 0.001). There was a nonsignificant improvement in unplanned readmission [0% versus 8% versus 10.7% (p = 0.163)], 30-day mortality [0% versus 0.5% versus 0% (p = 0.359)], and 90-day mortality [0% versus 0.5% versus 0% (p = 0.363)] between EN, PP, and PD groups. Survival analyses showed no difference in OS when comparing EN versus PP (p = 0.443), and EN versus PD (p = 0317). Patients with LN metastases (p < 0.001) fared worse, and lymphovascular invasion, higher T category (T3-4) and M1 status were found as predictors for LN metastasis. CONCLUSIONS: EN may be considered for select patients leading to favorable outcomes. Because survival was worse in the rare cohort of patients with LN metastases, the predictors for LN metastasis identified here may aid in stratifying patients to EN versus resection.

Prognostic factors of pancreatic tumors in children and adolescents: a population study based on the surveillance, epidemiology, and end results database.

PURPOSE: Pancreatic tumors in children are uncommon, and data is scarce. The purpose of this study is to examine the prognostic factors of pediatric pancreatic tumors in a population-based cohort. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all pediatric patients with pancreatic tumors diagnosed between 1975 and 2018. The overall survival (OS) rates were determined using a Kaplan-Meier analysis. The log-rank test was used for univariate survival analysis. Cox proportional-hazards regression was used to determine the variables related to OS. RESULTS: We identified 195 children with pancreatic tumors, with a median age at diagnosis of 16 years. Tumors were classified as neuroendocrine tumors (33.8%), solid pseudopapillary tumors (SPTs) (32.3%), pancreatoblastoma (11.3%), and others (22.6%). Of the patients, 30.3% had distant metastases, and 69.7% had surgery. Pancreatoblastomas were more common in younger children, whereas solid pseudopapillary tumors were more common in female patients. Overall 1-year, 3-year, and 5-year survival rates for all patients were 90.3%, 79.2%, and 77.7%, respectively. The Cox proportional hazard regression revealed that SEER stage and surgery were significant independent predictors of overall survival. CONCLUSIONS: Pancreatic tumors are rare in children, and overall survival is grim except for SPTs. SEER stage and surgery were determined to be the most relevant determinants of OS in our study.

Outcome and survival were similar with laparoscopic and open pancreatectomy in 102 solid pseudopapillary neoplasms.

BACKGROUND: Solid pseudopapillary neoplasms of the pancreas (SPNP) are rare tumors predominantly in young women. We report the largest single-center cohort study comparing resection of SPNP by laparoscopic approach (LA) and the open approach (OA). METHOD: Between 2001 and 2021, 102 patients (84% women, median age: 30) underwent pancreatectomy for SPNP and were retrospectively studied. Demographic, perioperative, pathological, early and the long-term results were evaluated between patients operated by LA and those by OA. RESULTS: Population included 40 LA and 62 OA. There were no significant differences in demographics data between the groups. A preoperative biopsy by endoscopic ultrasound was performed in 45 patients (44%) with no difference between the groups. Pancreatoduodenectomy (PD) was less frequently performed by LA (25 vs 53%, p = 0.004) and distal pancreatectomy (DP) was more frequently performed by LA (40 vs 16%, p = 0.003). In the subgroup analysis by surgical procedure, LA-PD was associated with one mortality, less median blood loss (180 vs 200 ml, p = 0.034) and fewer harvested lymph nodes (11 vs 15, p = 0.02). LA-DP was associated with smaller median tumor size on imaging (40 vs 80mm, p = 0.048), shorter surgery (135 vs 190 min, p = 0.028), and fewer complications according to the median comprehensive complication index score (0 vs 8.7, p = 0.048). LA-Central pancreatectomy was associated with shorter surgery (160 vs 240, p = 0.037), less median blood loss (60 vs 200, p = 0.043), and less harvested lymph nodes (5 vs 2, p = 0.025). After a median follow-up of 60 months, two recurrences (2%) were observed and were unrelated to the approach. CONCLUSIONS: The LA for SPNP appears to be safe, should be applied cautiously in case of PD for large lesion, and was not associated with recurrence.

Pancreatic masses in children: a single-center experience over two decades.

Pancreatic masses are extremely rare in pediatric patients, with limited data available. This lack of data makes the diagnosis and management of these tumors in children extremely challenging. Therefore, we aimed to describe the presentations, clinical course, and outcomes of children with pancreatic tumors at our center. A retrospective analysis was performed of all pediatric patients diagnosed with pancreatic masses between 2003 and 2022 in an academic freestanding children's hospital. Data including demographics, clinical presentation, workup, management, and subsequent morbidity and mortality were collected and aggregated. Furthermore, we reviewed cases of pancreatic tumor resections in the National Surgical Quality Improvement Program - Pediatric (NSQIP-P) database to identify common adverse outcomes and measures for quality improvement. In total, 17 patients were identified at our institution. Diagnoses included solid pseudopapillary (n = 9), gastrinoma (n = 1), rhabdomyosarcoma (n = 2), pancreatoblastoma (n = 2), and insulinoma (n = 1). Two patients did not have a histopathologic diagnosis and were excluded from subsequent analysis. Overall, 12 patients underwent surgical intervention, with the most common procedures being pancreaticoduodenectomy and distal pancreatectomy, and all 12 were known to be alive at last contact. There were 3 deaths, all due to complications related to metastatic disease. Furthermore, 30-day postoperative outcomes in the NSQIP-P dataset for pancreatic surgeries in pediatric patients are excellent, with negligible morbidity and no mortalities after the index surgery. CONCLUSIONS: Children with pancreatic tumors amenable to surgical resection appear to have adequate long-term survival. Short-term outcomes at diagnosis are excellent and mainly appear to be influenced by the presence of metastatic disease at initial presentation. WHAT IS KNOWN: • Pancreatic masses are a rare entity in children with limited data on their presentation, management and surgical outcomes. • Solid Pseudopapillary tumors are one of the most common pancreatic tumors in children with a fair prognosis after surgical intervention. WHAT IS NEW: • Surgical management of pediatric patients with pancreatic tumors is safe and effective in patients who do not have aggressive tumor types or metastatic disease. • Our case series provides a notable cohort of these pancreatic tumors with insight into the presentation, management and outcomes of five of these tumor types.

Surgical Outcomes of Pancreatic Solid Pseudopapillary Neoplasm: Experiences of 24 Patients in a Single Institute.

Background and Objectives: The pancreatic solid pseudopapillary neoplasm (SPN), a rare tumor predominantly affecting young women, has seen an increased incidence due to improved imaging and epidemiological knowledge. This study aimed to understand the outcomes of different interventions, possible complications, and associated risk factors. Materials and Methods: This study retrospectively analyzed 24 patients who underwent pancreatic surgery for SPNs between September 1998 and July 2020. Results: Surgical intervention, typically required for symptomatic cases or pathological confirmation, yielded favorable outcomes with a 5-year survival rate of up to 97%. Despite challenges in standardizing preoperative evaluation and follow-up protocols, aggressive complete resection showed promising long-term survival and good oncological outcomes. Notably, no significant differences were found between conventional and minimally invasive (MI) surgery in perioperative outcomes. Histopathological correlations were lacking in prognosis and locations. Among the patients, one developed diffuse liver metastases 41 months postoperatively but responded well to chemotherapy and transcatheter arterial chemoembolization, with disease stability observed at 159 postoperative months. Another patient developed nonalcoholic steatohepatitis after surgery and underwent liver transplantation, succumbing to poor medication adherence 115 months after surgery. Conclusions: These findings underscore the importance of surgical intervention in managing SPNs and suggest the MI approach as a viable option with comparable outcomes to conventional surgery.

Single-cell RNA sequencing of solid pseudopapillary neoplasms of the pancreas in children.

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor in children. Its origin remains elusive, along with its pathogenesis. Heterogeneity within SPN has not been previously described. In addition, low malignant but recurrent cases have occasionally been reported. To comprehensively unravel these profiles, single-cell RNA sequencing was performed using surgical specimens. We identified the cell types and suggested the origin of pancreatic endocrine progenitors. The Wnt/ß-catenin pathway may be involved in tumorigenesis, while the epithelial-to-mesenchymal transition may be responsible for SPN recurrence. Furthermore, NOV, DCN were nominated as primary and S100A10, MGP as recurrent SPN marker genes, respectively. Our results provide insight into the pathogenesis of SPN.

Solid Pseudopapillary Neoplasms of the Pancreas: Clinicopathologic Analysis and a Predictive Model.

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare. They are considered low-grade malignancies, and a small percentage of patients experience recurrence or metastasis. It is critical to investigate associated biological behavior and identify patients at a risk of relapse. This was a retrospective study of 486 patients with SPNs who were diagnosed between 2000 and 2021. Their clinicopathologic features, including 23 parameters and prognoses were analyzed. Six patients (1.2%) presented with synchronous liver metastasis. A total of 21 patients experienced recurrence or metastasis postoperatively. The overall and disease-specific survival rates were 99.8% and 100%, respectively. The 5- and 10-year relapse-free survival (RFS) rates were 97.4% and 90.2%, respectively. Tumor size, lymphovascular invasion, and the Ki-67 index were independent predictors of relapse. Furthermore, a Peking Union Medical College Hospital-SPN risk model was built to evaluate the risk of relapse and compared it with the American Joint Committee on Cancer tumor staging system (eighth edition, 2017). Risk factors included 3 parameters: tumor size (>9 cm), lymphovascular invasion status (presence), and Ki-67 index (>1%). Risk grades were available for 345 patients, who were divided into 2 groups: (1) low risk (n = 124) and (2) high risk (n = 221). The group with no risk factors was designated as low risk and had a 10-year RFS of 100%. The group associated with 1 to 3 factors was designated as high risk, with a 10-year RFS of 75.3%. Receiver operating characteristic curves were generated, and the area under the curve was 0.791 for our model and 0.630 for the American Joint Committee on Cancer with respect to the cancer staging system. We validated our model in independent cohorts and demonstrated a sensitivity of 98.3%. In conclusion, SPNs are low-grade malignant neoplasms that rarely metastasize, and the 3 selected pathologic parameters can be used to predict their behavior. A novel Peking Union Medical College Hospital-SPN risk model was proposed for routine application to guide the patient counseling in clinical practice.

Presumed radiological diagnosis of solid pseudopapillary tumors: do we really know what we are watching?

OBJECTIVES: Little is known about the clinicians' ability to ascertain the identity of a pancreatic lesion as solid pseudopapillary tumors (SPT)preoperatively. We led this retrospective study to figure out the disease spectrum that mimic SPT, the key features of SPT and the accuracy of CT and MRI in characterizing them. METHODS: Radiological and clinical database at a tertiary pancreatic disease center (Peking Union Medical College Hospital) was searched for patients who received CT or MRI with a presumed radiological diagnosis of SPT. Those patients' clinical information and final pathological diagnosis were collected. RESULTS: During 2018.10-2021.12, 200 patients had a presumed radiological diagnosis of SPT, and 132 of them had unambiguous pathological diagnosis. SPT were confirmed in only 63.6% (84/132), while the others had a variety of neoplastic and nonneoplastic lesions, including pancreatic neuroendocrine tumors (n = 15), pseudocysts (n = 4), mucinous cystic neoplasms (n = 4), serous cystadenomas (n = 3), neural sheath tumors (n = 3), lymphoepithelial cysts (n = 2), and several very rare pathologies (n = 17). Of note, 11.4% (15/132) of those were benign or nonneoplastic lesions, while 6.8% (9/132) were neoplasms with highly aggressive nature, or pancreatic metastases, which require systematic evaluation and staging instead of upfront surgery. Retrospective radiological analysis based on key imaging features, clinical history and laboratory findings had an improved diagnostic accuracy of 78.5% with CT and 77.8% with MRI. CONCLUSIONS: There is a broad disease spectrum mimicking SPT at CT and MRI. Key imaging features, clinical information and laboratory findings must be integrated to improve the diagnostic accuracy.

Efficacy and predictive factors of endoscopic ultrasound-guided ethanol ablation in benign solid pancreatic tumors.

BACKGROUNDS AND OBJECTIVES: Endoscopic ultrasound-guided ethanol ablation (EUS-EA) has recently been introduced for the management of solid pancreatic tumors, including pancreatic neuroendocrine tumors (PNETs) and solid pseudopapillary tumors (SPTs). The study aims to evaluate the efficacy and predictive factors for response of EUS-EA in solid pancreatic tumors. METHODS: Between October 2015 and July 2021, 72 patients who underwent EUS-EA for solid pancreatic tumors were included. The study outcomes were to evaluate the efficacy of EUS-EA with complete remission (CR) and objective response, and their predictive factors. RESULTS: During follow-up, 47 patients were diagnosed with PNETs and 25 with SPTs. Eight cases reached CR and 48 reached objective response. When compared with SPTs, PNETs showed similar duration to reach CR (median not reached; p = 0.319), but shorter duration to reach objective response (PNETs: median 20.6 months, 95%CI 10.26-30.88; SPTs: median 47.7 months, 95%CI 18.14-77.20; p = 0.018). Ethanol dosage > 0.35 ml/cm3 shortened the duration to reach CR (median not reached; p = 0.026) and objective response (median 42.5 months, 95%CI 25.34-59.66 vs. 19.6 months, 95%CI 10.17-29.09; p = 0.006). CR had no significant predictive factors, but PNETs showed significant predictive factors for objective response (HR 3.34, 95%CI 1.07-10.43; p = 0.038). Twenty-seven patients experienced adverse events, and there were two severe cases. CONCLUSION: EUS-EA for pancreatic solid lesions seems feasible as a local treatment for patients who refuse or are unfit for surgery. Additionally, PNETs seem to be the better candidate for EUS-EA.

Solid pseudopapillary neoplasms of the pancreas in childhood and adolescence-an analysis of the German Registry for Rare Pediatric Tumors (STEP).

Solid pseudopapillary neoplasms (SPNs) are the most common entity among pediatric pancreatic tumors. Still, these are rare tumors with an annual incidence of 0.1-0.2/1,000,000, and little is known about their optimal treatment. This analysis aimed to increase knowledge about the occurrence and treatment strategies of SPN in childhood. Data regarding diagnostics, treatment, and outcome of children aged 0-18 years with SPN recorded in the German Registry for Rare Pediatric Tumors (STEP) were analyzed. Thirty-eight patients were identified with a median age of 14.5 years at diagnosis (range: 8-18) and a female preponderance (81.6%). The most frequent location of the tumor was the pancreatic tail. In histopathological and immunohistochemical examination, pseudopapillary, solid, and cystic lesions as well as expression of beta-catenin, progesterone receptors, and cyclin D1 were the most common findings. All patients underwent surgical resection. Most patients underwent open resection, predominantly tail resection for tumors in the tail region and pylorus-preserving pancreaticoduodenectomy for tumors in the head region. The main postoperative sequela was exogenous pancreatic insufficiency (23.7%), especially with SPN in the pancreatic head. No recurrence occurred during follow-up, although two patients underwent resection with microscopic residue. CONCLUSION: SPN of the pancreas in childhood are low-grade malignancies with usually favorable treatment outcomes. However, therapy can lead to relevant long-term sequelae. To prevent recurrence, complete surgical resection is recommended, sparing as much healthy pancreatic tissue as possible. Interdisciplinary collaboration between specialists is essential to optimize treatment. Molecular genetic analysis of these tumors could improve understanding of their genesis. WHAT IS KNOWN: • Solid pseudopapillary neoplasms (SPNs) of the pancreas are very rare tumors in childhood. • Little is known about tumorigenesis, and there are no specific guidelines for treatment and follow-up in pediatric patients. WHAT IS NEW: • Characteristics, treatment, and outcome were comprehensively assessed in a large cohort of pediatric patients with SPN. • We propose recommendations for diagnosis, treatment, and follow-up of children with SPN, based on our analysis and considering published experience.

CT target scanning in the diagnosis of solid pseudopapillary tumor of the pancreas.

OBJECTIVE: To discuss the value of computed tomography (CT) iterative reconstruction technique combined with target scanning in the diagnosis of solid pseudopapillary tumor of the pancreas (SPTP). METHODS: The clinical information and CT examination data of 27 patients with SPTP were retrospectively analyzed, and the general condition and CT performance of the patients were observed. The CT image reconstruction algorithm of all patients used iterative reconstruction technique combined with the application of target scanning technique. RESULTS: A total of 27 patients were included in this study, including 6 males and 21 females, aged 14-72 years with a mean age of 39.6 ± 13.6 years. SPTP was more common in young and middle-aged females, with a low level of tumor markers, dominated by cystic-solid tumors. The combination of CT iterative reconstruction technology and targeted scanning revealed the following: the capsule of SPTP was clear and complete, where calcifications were visible, solid components were progressively enhanced, and rare pancreatic and bile duct dilation was seen. Tumors were cystic-solid in 18 of 27 patients with SPTP, of which the solid components showed isodensity or slightly low-density, with calcifications. The solid components and cyst walls were mildly enhanced during the arterial phase, and were progressively enhanced during the parenchymal phase, portal vein phase, and delayed phase, with their enhancement degree lower than that of normal pancreatic parenchyma, and pancreatic and bile duct dilation was rare. There were no statistical differences in tumor location, morphology, growth pattern, integrity of capsule, cystic or solid, calcifications, and enhancement features between the male group and the female group (P > 0.05). CONCLUSION: The iterative reconstruction combined with target scanning clearly displayed the CT features of tumors, helping the diagnosis and clinical treatment of the disease.

Clinical Characteristics of Patients With Surgically Resected Pancreatic Cysts: A Retrospective Analysis of 136 Patients.

OBJECTIVES: To retrospectively analyze the characteristics of pancreatic cysts with respect to histopathological diagnosis and various diagnostic imaging tools. METHODS: The clinical features of 136 patients and characteristics of histopathologically diagnosed cysts were retrospectively assessed. The diagnostic accuracy of endoscopic ultrasound (EUS), computed tomography (CT), and magnetic resonance imaging (MRI) for pancreatic cysts was compared. Risk factors for high-grade dysplasia/invasive cancer in patients with intraductal papillary mucinous neoplasms (IPMNs) were also determined. RESULTS: The final analysis included 30 serous cystic neoplasms (SCNs) (21.6%), 13 mucinous cystic neoplasms (MCNs) (9.4%), 65 IPMNs (46.8%), and 13 solid pseudopapillary neoplasms (SPNs) (9.4%). The percentage of women with MCNs, SPNs, SCNs, and IPMNs was 100.0, 76.9, 73.3, and 47.7%, respectively (P < .001). The percentages of patients over 60 years of age with IPMNs, SCNs, MCNs, and SPNs were 73.9, 23.3, 0, and 0%, respectively (P < .001). The percentage of cysts located in the body and tail of the pancreas in MCNs, SCNs, SPNs, and IPMNs was 100, 70, 53.9, and 46.2%, respectively (P < .001). A unique honeycomb appearance was observed in 26.7% of SCNs. The overall diagnostic accuracy of EUS, CT, and MRI for pancreatic cysts was 82.6, 72.5, and 73.9%, respectively. Lesion size and presence of solid components were independent predictors of high-risk IPMNs. CONCLUSIONS: Patient characteristics and cyst features can help to differentiate pancreatic cyst types and identify high-risk IPMNs. The diagnostic accuracy of EUS for pancreatic cysts is superior to that of CT and MRI.

Perioperative safety and prognosis following parenchyma-preserving surgery for solid pseudopapillary neoplasm of the pancreas.

BACKGROUND/OBJECTIVES: To evaluate perioperative safety and outcome of parenchyma-preserving pancreatectomy and risk factors of metastasis and recurrence for patients with solid pseudopapillary neoplasm (SPN). METHODS: Demographic data, operative and pathological parameter, follow-up data of patients with SPN undergoing their first operation were collected in our single center from May 2016 to October 2021 and compared between regular pancreatectomy group and parenchyma-preserving surgery group. Risk factors for metastasis and recurrence were investigated. RESULTS: A total of 194 patients were included, 154 of whom were female and the average age of all patients was 33 years old. Most patients were asymptomatic, with the most common complaint being abdominal pain or discomfort. Of them, 62 patients underwent parenchyma-preserving pancreatectomy including middle segment pancreatectomy and enucleation, and 132 patients underwent regular pancreatectomy including pancreaticoduodenectomy, distal pancreatectomy and total pancreatectomy. Patients in the parenchyma-preserving surgery group had a shorter duration of operation, less intraoperative bleeding, and decreased risk of combined organ removal and blood transfusion, with no statistical significance yet. The two groups exhibited a similar incidence of postoperative complications including grade B and C pancreatic fistula, delayed gastric emptying, postoperative pancreatic hemorrhage, and other complications, as well as radiological intervention, relaparotomy and the length of postoperative hospital stay. There were no perioperative deaths. All the patients, except 18 of those who discontinued follow-up, were alive with a median follow-up time of 31 months. Three patients in the regular pancreatectomy group were observed to have liver metastasis, and no metastasis was observed in the parenchyma-preserving surgery group. Significant risk factors for tumor metastasis and recurrence were tumor size, angioinvasion, and nerve infiltration. CONCLUSIONS: Parenchyma-preserving surgery did not significantly increase the frequency of perioperative complications or recurrence and might be preferable if comprehensive conditions allow.

Surgical outcome and prognosis of pediatric solid-pseudopapillary neoplasm.

BACKGROUND: The aim of this study was to clarify the characteristics and outcomes of pediatric patients with solid pseudopapillary neoplasms (SPNs) who underwent pancreatectomy. METHODS: Pediatric patients with SPNs who underwent pancreatectomy at our institution between 1995 and 2020 were included in the study. RESULTS: During the period under review, 12 patients underwent pancreatectomy for SPNs (median age: 10 years; range: 6-15 years). The surgical procedures included pancreatoduodenectomy (n = 2; 16.6%), distal pancreatectomy (n = 3; 25%), and enucleation (n = 7; 58.3%). The most common postoperative complication was postoperative pancreatic fistula (n = 6; 50%). Patients who underwent enucleation tended to have higher postoperative complication rates compared with those who underwent other procedures. All patients were alive without recurrence at the end of the study period. CONCLUSIONS: SPN is associated with a good prognosis, regardless of the surgical procedure. If surgeons select enucleation for pediatric SPNs, they should bear in mind that it is associated with a higher complication rate.

Solid pseudopapillary tumor of the pancreas: A systematic review of clinical, surgical and oncological characteristics of 1384 patients underwent pancreatic surgery.

BACKGROUND: Pancreatic solid pseudopapillary tumors (SPTs) are rare clinical entity, with low malignancy and still unclear pathogenesis. They account for less than 2% of exocrine pancreatic neoplasms. This study aimed to perform a systematic review of the main clinical, surgical and oncological characteristics of pancreatic SPTs. DATA SOURCES: MEDLINE/PubMed, Web of Science and Scopus databases were systematically searched for the main clinical, surgical and oncological characteristics of pancreatic SPTs up to April 2021, in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) standards. Primary endpoints were to analyze treatments and oncological outcomes. RESULTS: A total of 823 studies were recorded, 86 studies underwent full-text reviews and 28 met inclusion criteria. Overall, 1384 patients underwent pancreatic surgery. Mean age was 30 years and 1181 patients (85.3%) were female. The most common clinical presentation was non-specific abdominal pain (52.6% of cases). Mean overall survival was 98.1%. Mean recurrence rate was 2.8%. Mean follow-up was 4.2 years. CONCLUSIONS: Pancreatic SPTs are rare, and predominantly affect young women with unclear pathogenesis. Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

Pancreatic Cystic Tumors: A Single-Center Observational Study.

Background and Objectives: The aim of the study was to analyze the prevalence and characteristics of pancreatic cystic tumors (PCTs). Material and Methods: A retrospective analysis of the medical records of 124 patients, 102 (69%) women and 46 (31%) men, who had undergone surgery for pancreatic cystic tumors in 2014-2018. Among 148 pancreatic cysts, 24 (16%) were non-neoplasmatic and 124 (84%) were neoplasmatic. The neoplasmatic cysts (n = 124) were included in our analysis. There were five main types of PCTs: IPMN (intraductal papillary mucinous neoplasm) (n = 45), MCN (mucinous cystic neoplasm) (n = 30), SCN (serous cystic neoplasm) (n = 28), SPN (solid pseudopapillary neoplasm) (n = 8), and CPEN (cystic pancreatic endocrine neoplasm) (n = 8), as well as mixed-type tumors (n = 5). Results: A statistically significant dependency between PCT type and age was proven (p= 0.0001): IPMNs were observed in the older group of patients with an average age of 66.12 (40-79) years while SPNs were noted in the youngest group of patients with an average age of 36.22 (22-55) years. A statistically significant association between PCT type and gender (p = 0.0001) was found: IPMNs occurred among 24 (53.33%) men and 21 (46.6%) women. In the MCN and SPN groups, all patients were female (100%). Among the SCN group, the majority were women (27 (96.43%)), and there was only 1 (3.57%) man. A statistically significant dependency between PCT type and size was proven (p = 0.0007). The mean size of IPMNs was the smallest 2.95 (0.6-10 cm) and the mean size of MCNs was the largest 6.78 (1.5-19 cm). A statistically significant dependency between PCT type and tumor location was proven (p = 0.000238). The most frequent location of IPMN was the pancreatic head: 27 (60%). MCN was most frequently located in the pancreatic tail (18 (60%)). Most (10/28) SCNs were found in the pancreatic tail (10 (35.71%)). CPENs were most frequently located in the pancreatic tail (three (37.5%)) and pancreatic body and tail (three (37.5%)). SPNs were located commonly in the pancreatic head (five (62.5%)). The type of surgery depended on the tumor location. The most frequent surgery for IPMNs was pancreatoduodenectomy (44.4%), while for MCNs and SCNs, it was distal pancreatectomy (81%). The postoperative morbidity and mortality were 34.68% and 1.61%, respectively. Postoperative pancreatic fistula (POPF) was the most frequent (29%) complication. Conclusions: IPMN was the most frequent resected PCT in our material. A statistically significant association between the type of cyst and location within the pancreas, size, local lymph node involvement, and patient's age and sex was proved. POPF was the most frequent postoperative complication. In patients with PCTs, due to substantial postoperative morbidity, adequate patient selection, considering both the surgical risk as well as the long-term risk of malignant transformation, is very important during qualification for surgery.

Age in combination with gender is a valuable parameter in differential diagnosis of solid pseudopapillary tumors and pancreatic neuroendocrine neoplasm.

BACKGROUND: The clinicopathological characteristics of solid pseudopapillary tumor (SPT) and pancreatic neuroendocrine neoplasm (pNEN) are different. We, therefore, systematically investigated the performance of the clinicopathological characteristics in distinguishing SPT from pNEN. METHODS: We collected the cases from the Surveillance, Epidemiology, and End Results Program. The International Classification of Diseases for Oncology, third edition (ICD-O-3) for tumors was used to identify patients with pNEN or patients with SPT. To determine the performance of age in combination with gender in distinguishing SPT from pNEN, a nomogram was developed and the performance of this nomogram was evaluated by the receiver operating characteristic curve and the area under the curve (AUC). RESULTS: In the training cohort, 563 patients with pNENs and 30 patients with SPTs were recruited. The logistic regression and receiver operating characteristic curves suggest that age, gender, T-stage, N-stage, and M-stage could discriminate SPT and pNEN. The AUC of age, gender, T-stage, N-stage, and M-stage was 0.82, 0.75, 0.65, 0.69, and 0.70, respectively. Based on the nomogram, we observed that the AUC of age and gender is significantly high than that of the T-stage, N-stage, and M-stage. CONCLUSIONS: The present study proposes a non-invasive nomogram that could aid in the differential diagnosis of pNEN and SPT. This might help the clinicians to distinguish SPT from pNEN and choose the appropriate treatments for the patients.

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.

Comparison of splenic vessel preserving distal pancreatectomy and the Warshaw technique for solid pseudopapillary neoplasm in children.

PURPOSE: Spleen-preserving distal pancreatectomy (SPDP) such as splenic vessel preservation (SVP) for solid pseudopapillary neoplasms (SPNs) in the body or tail of the pancreas in children prevents post-splenectomy infection and hematologic disorders. However, SVP could be technically challenging, and the Warshaw technique (WT) could be an alternative technique that has been reported to be safe and effective in adults. We, therefore, compared the perioperative outcomes of SVP and WT in pediatric patients. METHODS: We retrospectively reviewed the medical records of pediatric patients with SPN who underwent SPDP using SVP or WT between November 2002 and November 2018 at a large-sized tertiary referral center. RESULTS: Twenty-eight patients were included. Sixteen (57.1%) patients underwent SVP and 12 (42.9%) patients underwent WT. There were no significant differences in the baseline characteristics between the two groups. Postoperative complications occurred in 8 patients each in the SVP (50%), and the WT (66.7%) groups. Two (12.5%) in the SVP group and 1 (8.3%) in the WT group required additional intervention. During a median follow-up duration of 49 months, there were no significant differences in the incidence of splenic infarctions or perigastric varices between the two groups. CONCLUSIONS: There were no significant differences in the surgical outcomes between WT and SVP in pediatric patients with SPN. WT could be a safe and feasible alternative technique for SVP in challenging cases.