Natural history and malignant risk factors of solid pseudopapillary tumors of the pancreas

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.

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.

Diagnosis and Management of Pancreatic Cysts: A Comprehensive Review of the Literature

The prevalence of pancreatic cysts has been rising due to the widespread use of cross-sectional imaging (CT scan and MRI) of the abdomen. While most pancreatic cysts are benign and do not require treatment or surveillance, a significant minority are premalignant and rarely malignant. The risk stratification of these lesions is not straightforward, and individual risk assessment, cyst size, distribution, and alarming morphologic features (when present) can guide the next steps in management. Neoplastic pancreatic cysts are mucinous or non-mucinous. Endoscopic ultrasound with fine-needle aspiration is often required to classify pancreatic cysts into mucinous and non-mucinous cysts and to assess the malignant potential. Advances in endoscopic techniques (confocal laser endomicroscopy, microforceps biopsy) can provide a definitive diagnosis of pancreatic cysts in some cases; however, the use of these techniques involves a higher risk of adverse events.

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.

Analysis of invasiveness and tumor-associated macrophages infiltration in solid pseudopapillary tumors of pancreas

BACKGROUND

Solid pseudopapillary tumor (SPT) is a rare pancreatic tumor. Considering its malignant behaviors, SPT has been classified as a low-grade malignant tumor. Indeed, only 9.2% of all SPT patients are initially diagnosed as malignant with invasion or metastasis. Thus, one of the challenges in managing SPT patients is predicting malignant behavior.

AIM

To investigate the malignant behavior and tumor-associated macrophage (TAM) infiltration between different histopathologic features of SPT patients.

METHODS

Twenty-five formalin-fixed paraffin-embedded tissue samples from 22 patients pathologically diagnosed with an SPT between 2009 and 2019 at West China Hospital were included in this retrospective study. Integrity of the capsule and growth pattern of the tumor cells was assessed microscopically in hematoxylin-eosin (HE)-stained sections. Based on the histopathological features, the SPT patients were divided into two groups: capsule or invasion. Clinical features, malignant behavior, and TAM infiltration were compared between the two groups.

RESULTS

Among the 22 SPT patients, 11 were identified for each group, having either a capsule or invasion histopathologic feature. Malignant behavior was more frequent in the invasion group, including 2 patients who had peripheral organ invasion, 3 with liver metastasis, and 1 with both lymph node and spleen metastases (P= 0.045). Ki-67 index of more than 3% was also more frequent in the invasion group (P = 0.045). Immunohistochemical analysis showed that the invasion group had a significant increase of CD68-positive TAMs in intratumor and peritumor sites in comparison with the capsule group (all P < 0.0001). Similarly, CD163-positive M2-like macrophages were also markedly increased in the intratumor and peritumor sites in the invasion group (all P < 0.0001). At the liver metastasis site, both intratumor and peritumor tissues showed relatively high-level CD68-positive TAMs and CD163-positive M2-like macrophages infiltration. However, the differences between the intratumor, peritumor and normal hepatic tissues did not reach statistical significance (all P > 0.05).

CONCLUSION

SPT patients with invasion evident under microscope were more likely to exhibit malignant behavior and TAM infiltration, especially M2-like macrophages. This finding can help in future investigations of the underlying mechanism of TAM-mediated SPT malignant behavior.

Clinical significance of pancreatic calcifications: a 15-year single-center observational study

Objectives

Pancreatic calcifications (PC) are considered specific for chronic pancreatitis (CP), but PC may also be present in non-CP diseases. The aims are to understand the pattern of calcifications in different diseases and to determine they were related to malignant diseases.

Methods

A retrospective study was performed including patients with PC or CP undergoing surgery in the Department of General Surgery of Ruijin Hospital from January 2003 to June 2018.

Results

PC were observed in 168 (4.5%) of the 3755 patients with pancreatic lesions treated during the study period. The majority of patients with PC had three kinds of CP (73.2%) while 26.8% had other five kinds of non-CP diseases. In patients with non-CP diseases, the incidence of PC in malignant intraductal papillary mucinous neoplasm (IPMN) was significantly higher than benign IPMN (8.3% vs. 0.7%, p = 0.004). In patients of CP with pancreatic mass (n = 81), PC (Odds ratio = 28.6, p = 0.000), advanced age (> 55 years) and parenchymal atrophy were independent predictors for malignancy. In patients of CP without pancreatic mass (n = 110), there were 82 cases (74.5%) with PC and 5 cases (4.5%) with pancreatic ductal adenocarcinoma. The regression model of risk factors was not successful.

Conclusions

The disease spectrum with PC was very diverse. PC may be related to malignant IPMN in non-CP diseases and is related to malignancy in the patients of CP with pancreatic mass and indications for resection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00725-9.

A systematic review and meta-analysis of predictors of recurrence in patients with Solid Pseudopapillary Tumors of the Pancreas

BACKGROUND

The recurrence rates and predictors of recurrence in patients with Solid Pseudopapillary tumors (SPT) are unclear, which makes it challenging to determine the duration of follow-up. The aim of the current study was to perform a systematic review and meta-analysis to determine the recurrence rates and pathologic factors associated with recurrence in patients with SPT.

METHODS

A PubMed, Scopus, and Web of Science search was conducted to identify studies of SPT published during the last 15 years: (09/2002-09/2017). Studies reporting on patients with SPT and follow-up of >5 years were included. The search strategy was conducted per 2009 PRISMA guidelines.

RESULTS

A total of 103 studies reporting on 2599 non-metastatic SPT patients were identified. Sixty-nine patients (2.6%) developed recurrence during follow-up. Pooled estimates from studies with a sample size >20 (N = 33) noted an overall recurrence rate of 2% (95% CI 1-2%). Male gender (OR 1.960), positive lymph nodes (OR 11.9), R1 margins (OR 11.1), and LVI (OR 5.5), were associated with a significantly (all p < 0.05) increased risk of recurrence.

CONCLUSION

Current meta-analysis suggests that only 2% of patients with SPT experience recurrence after resection. These data will guide the treating physicians and patients regarding recurrence rates and help identify patients at increased risk of recurrence during follow-up.

Clinical manifestations and multi-slice computed tomography characteristics of solid pseudopapillary neoplasms of the pancreas between males and females

Background

Solid-pseudo papillary neoplasms of pancreas (SPNP) are rare in men and are often misdiagnosed. This study aimed to analyze the clinical and multi-slice computer tomography (MSCT) features of patients with SPNP, and examine the differences between males and females.

Methods

In this retrospective cohort study, the clinical and imaging data of 29 patients with histolopathologically confirmed SPNP (seven males and 22 females) that underwent radical resection, and underwent preoperative MSCT at the First People’s Hospital of Lianyungang between August 2010 and December 2018 were collected. All MSCT images were reviewed by two radiologists; disagreements were ruled by a third one.

Results

The median age of the 29 patients with SPNP was 30 (range, 12–70) years. The male patients were older than the female patients [median, 56 (28–66) vs. 29 (12–70), P = 0.012]. The median tumor size was 3.9 (range, 2.0–6.4) cm in the male SPNP patients, which was significantly lower than the 7.0 (range, 4.6–14.6) cm in the female patients (P < 0.001). The calcification rate of the SPNP was significantly higher in male than in female patients (P = 0.013). The percentage of solid tumor was higher in males than in females (P = 0.036). Capsule, bleeding, and enhancement in the arterial and venous phases were not significantly different between the male and female patients (all P > 0.05).

Conclusion

The imaging features of male SPNP are distinct from those of female patients. In males with pancreatic lesions, MSCT generally shows relatively small lesions with higher percentages of solid components and calcification, with typical enhancement suggesting SPNP.

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.

Prediction of malignancy and adverse outcome of solid pseudopapillary tumor of the pancreas

Since solid pseudopapillary tumor of the pancreas (SPTP) was officially classified by the World Health Organization in 1996, SPTP has recently received special attention in the literature. Studies have shown that SPTP is a heterogeneous tumor, with a small percentage of patients harboring aggressive behaviors. However, criteria for malignancy grade in SPTP have not been well established. The prognosis of SPTP is generally good, with cases having a chance for long-term survival even with recurrence and/or metastasis after surgical resection. The current American Joint Committee on Cancer/Union for International Cancer Control tumor, node, metastasis staging system is not specific to SPTP. The lack of a predictive staging classification that accurately describes the heterogeneity of this disease hinders meaningful research into optimal individualized therapy. Here we summarize and discuss the associated factors proposed for appraisal of the malignant potential and adverse outcome of SPTP.

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.

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.

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

Background and aim

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

Method

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

Results

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

Conclusion

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

Solid-Pseudopapillary Tumor of the Pancreas: A Single Center Experience

Aim of this study was to review the institutional experience of solid-pseudopapillary tumors of the pancreas with particular attention to the problems of preoperative diagnosis and treatment. From 1997 to 2013, SPT was diagnosed in 18 patients among 451 pancreatic cystic neoplasms (3.7%). All patients underwent preoperative abdominal ultrasound, computed assisted tomography, and tumor markers (CEA and CA 19-9) determinations. In some instances, magnetic resonance, positron emission tomography, and endoscopic ultrasound with aspiration cytology were performed. There were two males and 16 females. Serum CA 19-9 was slightly elevated in one case. Preoperative diagnosis was neuroendocrine tumor (n = 2), mucinous tumor (n = 2), and SPT (n = 14). Two patients underwent previous operation before referral to our department: one explorative laparotomy and one enucleation of SPT resulting in surgical margins involvement. All patients underwent pancreatic resection associated with portal vein resection (n = 1) or liver metastases (n = 1). One patient died of metastatic disease, 77 months after operation, and 17 are alive and free with a median survival time of 81.5 months (range 36–228 months). Most of SPT can be diagnosed by CT or MRI, and the role of other diagnostic tools is very limited. We lack sufficient information regarding clinicopathologic features predicting prognosis. Caution is needed when performing limited resection, and long and careful follow-up is required for all patients after surgery.

Pancreatic serous cystic neoplasms accompanying other pancreatic tumors

Serous cystic neoplasms (SCNs) are benign cystic neoplasms that predominantly occur in the tail of the pancreas in elderly women. It is well known that patients with von Hippel-Lindau syndrome can develop SCNs and neuroendocrine tumors in the pancreas. However, our understanding on SCNs accompanying other pancreatic tumors (SCNAOPTs) is limited. We compared the clinicopathological features of 15 surgically resected SCNAOPTs with 259 conventional SCNs. The prevalence of SCNAOPT was 5%. The SCNAOPTs were significantly smaller than conventional solitary SCNs, and they were more commonly observed in the head of the pancreas, whereas conventional solitary SCNs were more frequently noted in the body and tail. However, no differences were found in terms of sex, patient age, or the gross patterns of the SCNs. Accompanying neoplasms included 7 intraductal papillary mucinous neoplasms, 1 colloid carcinoma arising from intraductal papillary mucinous neoplasm, 6 neuroendocrine tumors, and 1 solid pseudopapillary neoplasm. Four neuroendocrine tumors associated with von Hippel-Lindau syndrome occurred as multiples, whereas 2 neuroendocrine tumors without von Hippel-Lindau syndrome were solitary. In summary, SCNAOPTs comprise 5% of all SCNs and tend to be smaller and located in the head of the pancreas. Common accompanying tumors include intraductal papillary mucinous neoplasms, neuroendocrine tumors, and other neoplasms such as colloid carcinoma and solid pseudopapillary neoplasm.

Pancreatic surgery for tumors in children and adolescents

PURPOSE

Pancreatic neoplasms are uncommon in children. This study sought to analyze the clinical and pathological features of surgically resected pancreatic tumors in children and discuss management strategies.

METHODS

We conducted a retrospective review of patients ≤21 years with pancreatic neoplasms who underwent surgery at a single institution between 1995 and 2015.

RESULTS

Nineteen patients were identified with a median age at operation of 16.6 years (IQR 13.5-18.9). The most common histology was solid pseudopapillary neoplasm (SPN) (n = 13), followed by pancreatic neuroendocrine tumor (n = 3), serous cystadenoma (n = 2) and pancreatoblastoma (n = 1). Operative procedures included formal pancreatectomy (n = 17), enucleation (n = 1) and central pancreatectomy (n = 1). SPNs were noninvasive in all but one case with perineural, vascular and lymph node involvement. Seventeen patients (89.5 %) are currently alive and disease free at a median follow-up of 5.7 (IQR 3.7-10.9) years. Two patients died: one with metastatic insulinoma and another with SPN who developed peritoneal carcinomatosis secondary to a concurrent rectal adenocarcinoma.

CONCLUSIONS

Pediatric pancreatic tumors are a heterogeneous group of neoplastic lesions for which surgery can be curative. SPN is the most common histology, is characterized by low malignant potential and in selected cases can be safely and effectively treated with a tissue-sparing resection and minimally invasive approach.

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.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predicting recurrence of pancreatic solid pseudopapillary tumors after surgical resection: a multicenter analysis in Korea

BACKGROUND

Solid pseudopapillary tumors (SPTs) of the pancreas are still considered a surgical enigma. Many clinical research trials have failed to identify prognostic factors that predict the malignant behavior of SPTs.

MATERIALS AND METHODS

This work was a retrospective multicenter study that included a total of 17 medical institutions. Data from 351 patients who underwent surgical resection from January 1990 to December 2008 were retrospectively collected using standardized case report forms requesting clinicopathologic features.

RESULTS

Thirty-four patients (9.7%) were male, and 317 (90.3%) were female, with a mean age of 36.8 ± 12.4 years. Recently, minimally invasive (P < 0.001) and parenchyma or function-preserving limited surgeries (P = 0.016) have been more frequently applied for the treatment of pancreatic SPTs. Ninety-eight patients (27.9%) had microscopic malignant features. Only 9 patients (2.6%) experienced tumor recurrence after the initial pancreatic SPT resection. Multivariate analysis showed that a tumor size larger than 8 cm [Exp (β) = 7.385, P = 0.018], microscopic malignant features [Exp (β) = 10.009, P = 0.011], and stage IV [Exp (β) = 42.003, P = 0.002] were significant prognostic factors for tumor recurrence. When combined with stage IV, the microscopic malignant features and 2010 World Health Organization definition of solid pseudopapillary carcinoma more successfully differentiated future recurrence risk groups (P < 0.001).

CONCLUSIONS

More specific pathologic descriptions need to be employed in pathologic report forms to provide proper information to predict SPT recurrence after resection. Future studies emphasizing the standardized pathologic evaluation of pancreatic SPTs may unveil the enigmatic nature of pancreatic SPTs.

Solid pseudopapillary tumor of the pancreas with liver metastasis: Clinical features and management

OBJECTIVE

To summarize the diagnosis and management of metastatic pancreatic solid pseudopapillary tumors (SPTs).

METHODS

We retrospectively analyzed the clinical data of patients with metastatic pancreatic SPTs who were admitted to Peking Union Medical College Hospital from November 2001 to September 2013.

RESULTS

A total of 187 patients with pancreatic SPTs were admitted. Four patients had liver metastasis, and all four were female patients aged 20-72 years old. Each patient with metastases underwent surgical resection with good postoperative recovery. The mean follow-up period was 30 months (range, 1-64 months). None of the patients had obvious recurrence or distant metastasis.

CONCLUSIONS

Pancreatic SPT with liver metastasis is very rare, and surgical resection is an effective treatment option. The principle of surgical treatment is to resect the primary and metastatic lesions as completely as possible. The affected patients require long-term postoperative follow-up.

Solid pseudopapillary neoplasms of the pancreas: a report of two cases

Solid pseudopapillary neoplasms of the pancreas are uncommon, accounting for only 1-2% of all pancreatic neoplasms. These tumors are being detected at an increased rate, probably due to the increased awareness and the liberal use of imaging. We report two cases of patients with solid pseudopapillary pancreatic tumors and review the existing literature.