Single-institution experience with solid pseudopapillary neoplasm of the pancreas

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.

Endocrine therapy for metastatic solid pseudopapillary neoplasm of the pancreas: A case report

Solid pseudopapillary neoplasm (SPN) of the pancreas is an extremely rare tumor, associated with favorable prognosis and long-term survival in patients with advanced disease. However, limited data exist on systemic therapy for such patients. Herein, we present a case of a young woman with a history of SPN, who progressed after multiple surgical resections and chemotherapy regimens. The immunohistochemistry (IHC) showed overexpression of estrogen receptors (ER) and progesterone receptors (PR) in tumor tissue. The patient started to receive tamoxifen and showed a durable response to endocrine therapy.

Long-term survival following resection of a solid pseudopapillary tumour of the pancreas with arterial and venous encasement

Solid pseudopapillary neoplasms (SPNs) of the pancreas (also known as Franz tumours) are rare, representing 1%-2% of pancreatic tumours. They are of exocrine gland origin and are more prevalent in women under the age of 30. They are classified as low-grade malignancies and are usually treated with surgery.We present the case of a young woman who was found to have a pancreatic head lesion obstructing the superior mesenteric vein and encasing the superior mesenteric artery. Diagnosis of SPN was confirmed on histology. Initially deemed unresectable due to vascular encasement, the patient received neoadjuvant chemotherapy to downstage the tumour. This was unsuccessful. Given the patient's young age and lack of other options, surgery was performed. Instead of vascular resection, the tumour was split and peeled off the superior mesenteric artery giving an R1 resection. The patient has achieved long-term recurrence free survival at 10 years.

The Sex Features of Patients With Solid Pseudopapillary Neoplasms of the Pancreas: A Retrospective Study

Background

Solid pseudopapillary neoplasms of the pancreas (SPNs) in male patients are more frequently reported. The aim of the study was to evaluate the sex features of SPN and the risk factors that predict tumor recurrence.

Methods

From 2013 to 2019, patients who were pathologically confirmed to have SPNs were retrospectively reviewed. The baseline study parameters were compared between males and females. A logistic regression model was established to identify the independent risk factors for tumor recurrence.

Results

In total, 221 patients were included in this study. Of them, 53 patients (24.0%) were males. Male patients were older than female patients (39.1 vs 31.6 years, P=0.001), and the tumor size in male patients was smaller than that in female patients (50.38 vs 39.65 mm, P=0.038). The preoperative imaging diagnostic accuracy was significantly higher in females than in males (70.5% vs 54%, P=0.02). SPNs in male patients tended to be misdiagnosed with other malignant tumors (37.7% vs 10.7%, P<0.0001), with a more solid component observed in images (66.8% vs 24.7%, P<0.0001). For immunohistochemical staining, the expression of beta catenin was significantly lower in male patients (P=0.002), and the expression of vimentin was the opposite (P=0.01). The overall survival rate and disease-free survival were not different. Based on multivariate analysis, older age [hazard ratio (HR)= 1.094, 95% confidence interval (CI): 1.005-1.190] and KI 67 index grade III (HR=12.029, 95% CI: 2.399-60.311) were independent risk factors for tumor recurrence.

Conclusion

The clinical and imaging features of SPN in males were not in full accord with those in females; however, the differences did not influence prognosis.

Current highlights on solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor that predominantly affects young women in their third and fourth decade. Etiology and risk factors are unknown. Clinical symptoms are aspecific and most commonly due to mass effect. Diagnosis is made by computed tomography scan or magnetic resonance imaging and histological characterization is obtained by endoscopic ultrasound-guided fine needle biopsy. Microscopically, these lesions are composed by both solid and pseudopapillary structures with necrotic and hemorrhagic areas. Occasionally, the biological behavior is aggressive with tumor recurrence and distant metastasis. Usually, curative R0 surgical resection is the best option able to provide long term survival even in advanced disease. Unresectable disease is the main predictor of poor prognosis. Chemotherapy and radiotherapy regimens are not well standardized. However, they could be effective in reducing tumor size as neoadjuvant treatment or disease control in palliative setting. Although complete surgical resection provides a cure rate of > 95%, considering young age of the patients and morbidity associated to pancreatic surgery, further studies are needed to better investigate risk factors and responsiveness to hormones in order to allow early diagnosis and follow up strategies that could avoid unnecessary surgery in less aggressive disease.

Pancreatic solid pseudopapillary neoplasm: a single-institution study

BACKGROUNDS

Solid pseudopapillary neoplasms (SPNs) are a distinct but rare form of low-grade pancreatic neoplasia, accounting for 0.3%-2.7% of all pancreatic tumours. They are most common in young females. Local recurrence and distant metastasis are reported but extremely rare, and are usually resectable with curative intent. We report the clinicopathological features and long-term outcomes of SPNs following surgical resection from a single institution.

METHODS

A total of 1296 patients undergoing pancreatic resection during the 30 years period from 1991 to 2020 were retrospectively reviewed, and those with a confirmed pathological diagnosis of pancreatic SPN on review were included.

RESULTS

Twenty-two patients (1.7% of all patients undergoing resection), were identified. Twenty patients (91%) were female. Unlike previous studies, most patients (91%) were symptomatic at diagnosis. On diagnostic CT, cystic components were visible in 16 patients (73%), calcifications were found in two patients (9%), haemorrhage in one patient (5%) and a defined capsule was seen in four patients (18%). Surgical resection was undertaken on all cases, with distal pancreatectomy the most commonly performed (n = 11, 50%). One patient (4.7%) had nodal involvement, nine patients had an incomplete tumour capsule (41%) and seven patients (32%) had tumour extension into the pancreatic parenchyma. Despite this, no patients had disease recurrence at 10 years. One patient died within 5 years of heart failure unrelated to the SPN process; no patients died within 10 years of the disease.

CONCLUSION

We confirm a high proportion of female patients. Interestingly, a high proportion of our cohort was investigated for symptomatic disease. Despite a high proportion of tumours with an incomplete capsule, and extension into the pancreatic parenchyma, our findings indicated that SPN patients have excellent survival after margin-negative surgical resection.

Prediction of Recurrence of Completely Resected Pancreatic Solid Pseudopapillary Neoplasms in Pediatric Patients: A Single Center Analysis

Background: Many previous studies have investigated the risk factors for the recurrence of pancreatic solid pseudopapillary neoplasms (SPNs), although a consensus has not yet been reached, despite this effort. We aimed to identify the predictive factors for recurrence in patients with SPNs who underwent complete surgical resection of the tumor. Methods: We retrospectively analyzed the records of pediatric patients with SPNs who underwent surgical resection at a single center between 2001 and 2018. Results: During the study period, 47 patients with SPNs underwent radical resection of the tumor. The median age of the patients was 14 (8–18) years. R0 resection was confirmed in every case and none of the patients presented with systemic metastasis at the time of diagnosis. The median follow-up period was 53.1 (30.8–150.8) months. Of the 47 patients, only two (4.2%) experienced recurrence. Using comparative analysis, we found that some factors such as a large tumor size, peripancreatic tissue invasion, and capsule invasion did not increase the risk of recurrence of SPNs. Lymph node metastasis was the only significant factor for recurrence in our study (p = 0.043). Conclusion: During our single center analysis, we found that only lymph node metastasis was a predictive factor for recurrence of SPNs among patients who underwent complete tumor resection. Long-term follow-up is required to determine whether SPNs will recur if lymph node metastasis is observed after surgery. Furthermore, therapeutic benefits of routine lymphadenectomy or sentinel lymph node biopsy should be investigated in future studies to reduce the risk of recurrence in patients with SPNs.

Safety of Endoscopic Ultrasound-Guided Fine-Needle Aspiration for Pancreatic Solid Pseudopapillary Neoplasm Before Surgical Resection: A European Multicenter Registry-Based Study on 149 Patients

OBJECTIVES

The results of only a few endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic solid pseudopapillary neoplasm (SPN) have been published, and the safety of the procedure has never been investigated. Our study compared the recurrence rate in patients with and without preoperative EUS-FNA.

METHODS

This European multicenter registry-based study was conducted in 22 digestive units, and retrospectively included all patients who underwent complete resection of a pancreatic SPN from 2000 to 2018. Patients with and without initial EUS-FNA were compared, and postsurgery recurrence and the associated risk factors were evaluated.

RESULTS

A complete resection of a pancreatic SPN was performed in 149 patients (133 women, 89%), with a mean age of 34 (standard deviation, 14) years. There were no significant differences between the with (78 patients) and without (71 patients) EUS-FNA groups, except for age and tumor size and location.Preoperative EUS-FNA allowed pancreatic SPN diagnosis in 63/78 cases (81%). After a mean follow-up of 43 (standard deviation, 36) months, recurrence was noted in 4 patients (2.7%). Preoperative EUS-FNA was not correlated with recurrence, but an older age (P = 0.005) was significant.

CONCLUSIONS

Preoperative EUS-FNA does not affect pancreatic SPN recurrence. In this series, old age was significantly correlated with recurrence.

Outcome and prognosis after pancreatectomy in patients with solid pseudopapillary neoplasms

BACKGROUND

Solid pseudopapillary neoplasms (SPN) are rare and represent approximately 4% of all cystic pancreatic tumors. The prognosis is excellent, although 10-15% of SPN patients show metastasis at the time of surgery or tumor recurrence during follow-up after pancreatectomy. Aim of the study was to analyze surgical management, risk factors for malignancy as well as long-term outcome and prognosis of this distinct tumor entity.

METHOD

All patients with pancreatic resection for SPN between 10/2001 and 07/2018 in the authors' institution were identified from a prospective database. Clinicopathologic details, perioperative data and long-term follow-up results were retrospectively analyzed.

RESULTS

Fifty-two patients were identified, 44 (85%) of them were female and the median age was 29 years (IQR 9-71). Seven (13%) patients showed a malignant behaviour of SPN with N1 (n = 2) or M1 (n = 1) disease at resection; 5 patients developed tumor recurrence, after a median of 21 months. During follow-up time (median 54 months) all patients were alive, the 5- and 10-year rates for disease-free survival were 89.0% and 81.6%, respectively. Significant risk factors for recurrence were age <18 years (p = 0.0087) and parenchyma-preserving surgical approaches (p = 0.0006). The postoperative long-term outcome showed ECOG = 0-1 in all patients, with resection related exocrine insufficiency in 20 (41%) and diabetes mellitus in 2 (4%) patients.

CONCLUSIONS

Age < 18 years is a significant risk factor for malignancy in SPN, and parenchyma preserving resections harbor a significant risk for tumor recurrence. As recurrence may occur late, a systematic life-long follow-up should be performed.

Targeted next generation sequencing of pancreatic solid pseudopapillary neoplasms show mutations in Wnt signaling pathway genes

Solid pseudopapillary neoplasms of the pancreas are rare neoplasms that have been shown to harbor recurrent somatic pathogenic variants in the beta-catenin gene, CTNNB1. Here, we used targeted next generation sequencing to analyze these tumors for other associated mutations. Six cases of solid pseudopapillary neoplasms were studied. DNA extracted from formalin-fixed paraffin embedded tissue blocks was analyzed using the Ion Torrent platform, with the 50-gene Ampliseq Cancer Hotspot Panel v2 (CHPv2), with further variant validation performed by Sanger sequencing. Four tumors (67%) were confirmed to harbor mutations within CTNNB1, two with c.109T > G p.(Ser37Ala) and two with c.94G > A p.(Asp32Asn). One case showed a frameshift deletion in the Adenomatous Polyposis Coli gene, APC c.3964delG p.(Glu1322Lysfs*93) with a variant allele frequency of 42.6%. Sanger sequencing on non-tumoral tissue confirmed the variant was somatic. The patient with the APC mutation developed metastasis and died. In addition to the four cases harboring CTNNB1 variants, we found a case characterized by poor outcome, showing a rare frameshift deletion in the APC gene. Since the APC product interacts with beta-catenin, APC variants may, in addition to CTNNB1, contribute to the pathogenesis of solid pseudopapillary neoplasms via the Wnt signaling pathway.

Solid pseudopapillary neoplasm of the pancreas: Clinical-pathological features and management, a single-center experience

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of low malignancy that occurs most often in females. The study describes the clinicopathologic characteristics of the tumor and common differential diagnoses. Data were collected from a prospectively maintained database. Of 1661 patients operated for pancreatic tumors between January 2001 and September 2018, 15 patients were recorded. Patients included 12 females and 3 males, median age 40 (range 10 -87) years. Computed tomography or magnetic resonance imaging was diagnostic in eight patients and a preoperative biopsy in eight out of 10 patients. Median tumor size was 5 cm (range 2 -16 cm), 12 tumors were in the head, six in the body, and three in the tail of the gland. All patients except one had radical resection including one with hepatic and lymph node metastases, no patient underwent oncologic treatment. All patients are alive from 17.5 to 209.4 months postoperatively and without recurrence. Radical operation is usually curative and should also be offered to patients with metastases or recurrence as oncologic treatment has limited effect.

European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN.

Molecular dynamic simulation of mutated β-catenin in solid pseudopapillary neoplasia of the pancreas

Solid pseudopapillary neoplasia of the pancreas (SPN) is a rare pancreatic neoplasm that frequently harbors mutations in catenin β1 (CTNNB1, encoding β-catenin) as a part of its molecular pathogenesis. Mutations to CTNNB1 reported in SPN usually occur at the serine/threonine phosphorylation sites, including codons 33, 37 and 41, and the flanking residues of codon 33. On analysis of 3 cases of SPN, mutations to CTNNB1 were detected in codon 32 (D32A and D32Y). As this residue, aspartic acid, is not a direct phosphorylation site of the protein, molecular modeling tools were used to predict the influence of these mutations on the protein structure of β-catenin. A total of three MD simulations (wild-type, D32A, and D32Y) were performed to visualize the conformations of β-catenin under in vivo, aqueous-phase conditions at 37°C. In the wild-type protein, the secondary structure of residues P16-H28 remained helical; we therefore hypothesized that the helical structure of this protein fragment (residues M11-G50) was necessary for phosphorylation of S33 phosphorylation. The loss of the secondary structure in P16-H28 was observed in D32A, losing its helical structure and becoming a turn; however, in the D32Y mutant, the helical structure remained. The present demonstrated that structural changes in the mutated β-catenin protein at D32 could potentially explain the mechanism behind its defective phosphorylation in the pathogenesis of SPN.

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.

Pathology comparative study on the characteristic CT signs in solid pseudopapillary neoplasm of the pancreas

In order to analyze characteristic CT signs in the solid pseudopapillary tumor of the pancreas, a retrospective analysis was conducted on 49 patients with pseudopapillary tumor of the pancreas who where treated in Liaoning Cancer Hospital. All of the patients were confirmed by pathology, CT signs were analyzed and a pathology contrast was conducted. Furthermore, all cases had single lesions; 7 cases in the pancreatic head, 23 cases in the pancreatic body, 15 cases in the pancreatic body-tail and 4 cases in the pancreatic tail. The boundaries of the lesions were clear and the tumors, which may outline the pancreas, were composed of solid and polycystic parts. In addition, calcifications could be observed in the lesions and CT results revealed varying degrees of contrast enhancement of the solid components in the arterial phase, as well as a gradual contrast enhancement in the venous and delayed phase. Enhancement of capsule could be observed, and the enhancement region was observed in the solid part, no enhancement in cystic part.. In conclusion, CT manifestations of solid pseudopapillary tumors of the pancreas are specific, which is helpful to the diagnosis.

A Rare Case of Recurrent Metastatic Solid Pseudopapillary Neoplasm of the Pancreas

A 61-year-old woman visited our hospital for bilateral multiple lung nodules and a mass in her thorax. She had a long history of multiple metastatic recurrences of solid pseudopapillary neoplasm (SPN); 24 years previously, the patient had undergone pylorus-preserving pancreaticoduodenectomy for a 9.9 × 8.6 cm mass in the pancreatic head. The tumor was diagnosed as an SPN. Nine years later, metastatic nodules were found on computed tomography in the patient’s liver and peritoneum and were excised. She subsequently underwent an additional eight metastatectomy procedures in diverse organs. For the presented event, the lung nodules were removed. The prevalence of malignant SPN in the general population is 5%–15%. However, multiple metastatic recurrence of malignant SPN is rare; the lung is a particularly rare site of metastasis, found in only three cases in the literature. Here, we describe this exceptional case and provide a literature review.

Solid pseudopapillary tumor of the pancreas in a patient with cervical cancer: relation of E-cadherin/β-catenin adhesion complex in their carcinogenesis

Solid pseudopapillary tumor (SPT) of the pancreas is one of the most uncommon histotypes of all exocrine pancreatic neoplasms. Disorganization of E-cadherin and β-catenin mutations, two key components of the Wnt signal transduction pathway, has been implicated in the development of SPT, but not other pancreatic tumors. Loss of E-cadherin/β-catenin proteins and tyrosine phosphorylation of E-cadherin/β-catenin have been postulated in cervical carcinogenesis and cancer invasion. A 38-year-old married woman, who had undergone brachytherapy, radiotherapy and chemotherapy for cervical cancer in Philippines in 2011, was admitted to our hospital after follow-up CT scan of abdomen in 2012 revealed a lesion in the tail of pancreas. The patient underwent distal pancreatectomy and splenectomy. The pathological diagnosis was SPT of pancreas. We suspect that the concurrent SPT pancreas and cervical cancer in this woman were triggered by a primary insult, a process in which E-cadherin/β-catenin/Wnt-signaling pathway played important roles.

Pancreatic cystic neoplasms: Review of current knowledge, diagnostic challenges, and management options

Pancreatic cystic lesions are being detected with increasing frequency, largely due to advances in cross-sectional imaging. The most common neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, solid pseudopapillary neoplasms, and cystic pancreatic endocrine neoplasms. Computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS) are currently used as imaging modalities. EUS-guided fine needle aspiration has proved to be a useful diagnostic tool, and enables an assessment of tumor markers, cytology, chemistries, and DNA analysis. Here, we review the current literature on pancreatic cystic neoplasms, including classification, diagnosis, treatment, and recommendations for surveillance. Data for this manuscript was acquired via searching the literature from inception to December 2014 on PubMed and Ovid MEDLINE.

Clinical and pathological features of solid pseudopapillary neoplasms of the pancreas at a single institution

AIMS

The aim of this study was to determine the clinicopathological features and surgical management of solid pseudopapillary neoplasms (SPNs) of the pancreas at a single institution.

METHODS

We investigated 34 patients (5 males and 29 females) who underwent surgery for pathologically confirmed SPNs between 1994 and 2012.

RESULTS

Clinical symptoms were absent in 58.8% of the patients. The median tumor diameter was 42.7 mm. All tumors were successfully removed by R0 resection. Pathologically, 5.9% had duodenum invasion and 2.9% had pancreatic serosal invasion, but there was no lymph node metastasis. Radiological findings showed calcification in 39.4% of the patients, capsule formation in 51.5%, cystic components in 69.7%, solid components in 93.9% and internal bleeding in 36.4%. Immunohistochemically, neuron-specific enolase was positive in 100% of the patients, nuclear accumulation of β-catenin in 100% and CD10 in 78.8%. There were no recurrences reported at the median follow-up (67 months). Regarding gender differences, the cystic component in radiological imaging was the only significant finding among the features studied (p = 0.01).

CONCLUSIONS

R0 resection with appropriate procedures appears to be sufficient for patients with SPNs, even for locally invasive tumors. There were no significant differences between genders except for the cystic component on radiological imaging.

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.

A systematic review of solid-pseudopapillary neoplasms: are these rare lesions?

OBJECTIVE

The aim of the study was to determine if there had been any change in the number of solid-pseudopapillary neoplasm (SPN) cases detected and their evaluation or management over time.

METHODS

A systematic review of SPN was performed of all articles published in English in PubMed and Scopus.

RESULTS

A total of 2744 patients with SPN were identified in 484 studies published between 1961 and 2012; 87.8% of the cases were reported between 2000 and 2012. A total of 2408 (87.8%) were females, and the mean age was 28.5 (SD, 13.7) years. The most common symptom was abdominal pain in 63.6% of the cases and incidentally detected in 38.1% of the cases. There were 2285 patients who underwent pancreatic resection. The mean tumor size was 8.6 (SD, 4.3) cm. Follow-up was reported for 1952 (90.5%) patients, with a mean follow-up of 36.1 (SD, 32.8) months. Disease-free survival was documented in 1866 (95.6%) patients with recurrence in 86 (4.4%) patients; the median time to recurrence was 50.5 months.

CONCLUSIONS

The number of SPNs reported in the literature has seen a 7-fold increase in the number of cases reported since 2000 compared with before. Solid-pseudopapillary neoplasms continue to be primarily found in young women and present with nonspecific symptoms. Surgery remains the mainstay of treatment with an excellent long-term prognosis.

Pleomorphic solid pseudopapillary neoplasm of the pancreas: degenerative change rather than high-grade malignant potential

Solid pseudopapillary neoplasms (SPNs) are rare tumors of the pancreas characterized by poorly cohesive uniform cells with solid and pseudopapillary growth patterns. Nuclear pleomorphism is not a well-recognized feature of SPNs and may complicate differentiation from other pancreatic neoplasms. We compared histologic, immunohistochemical, and clinical features of 18 pleomorphic SPNs with 121 conventional SPNs. The prevalence of pleomorphic SPN was 12.9% (18/139). Pleomorphic SPNs arose in older patients (median, 45 years versus 32 years; P < .001), but no differences were found in sex, tumor location, recurrence, and metastasis when compared with conventional SPNs. Except for pleomorphic nuclei, other cytologic and histologic features of pleomorphic SPNs, such as growth pattern, tumor size, infiltrative pattern, tumor extension, mitosis, and Ki-67 labeling index, were not different from those of conventional SPNs. Pleomorphic SPNs showed a significantly higher p53 protein expression (64.7% [11/17 cases]) than that of conventional SPNs (1.8% [2/112 cases], P < .001). However, immunoreactivity for β-catenin and E-cadherin was not different between pleomorphic and conventional SPNs. A TP53 gene mutation was observed in 2 of 3 p53-immunoreactive pleomorphic SPNs. In summary, nuclear pleomorphism occurs in a subset of SPNs. They are more often p53 immunoreactive than SPNs without pleomorphism, and some harbor TP53 gene mutations. However, pleomorphic SPNs do not appear to be more aggressive than conventional SPNs. Low mitotic rate and Ki-67 labeling index may suggest nuclear pleomorphisms as degenerative changes. Recognition of typical poorly cohesive tumor cells and immunohistochemical features could establish the correct diagnosis of SPNs.

Solid-pseudopapillary neoplasm of the pancreas: cytomorphologic findings and literature review

BACKGROUND

Solid-pseudopapillary neoplasm (SPN) is a rare pancreatic malignancy with an excellent prognosis. It is most commonly diagnosed in young women. This article comprehensively reviews the clinical, pathological and radiological features of this neoplasm, as well as its clinical management.

METHODS

A literature review of SPN was performed of all articles published in the English language in PubMed prior to November 1, 2013. Cytomorphological features, histopathology, immunohistochemistry, patient general demographics, molecular studies, radiologic imaging and clinical management were reviewed.

RESULTS

SPN displays distinct cytomorphological features on fine-needle aspiration - thin, delicate, branching vessels in a 'Chinese character' pattern lined by one to several layers of loosely cohesive neoplastic cells. Nuclear features include indented or grooved nuclei with an evenly distributed chromatin pattern and small inconspicuous nucleoli. SPN is characteristically immunoreactive for CD10, β-catenin (in an abnormal nuclear pattern), CD99 in a perinuclear dot-like pattern, α1-antitrypsin, and progesterone receptor. Almost all SPNs harbor an activating point mutation in exon 3 of the β-catenin gene (CTNNB1). Clinicopathological features generally do not correlate with prognosis, and most patients experience excellent long-term survival.

CONCLUSIONS

SPN can mimic other neoplasms of the pancreas, which can lead to diagnostic challenges in a limited cytologic specimen. Distinct cytomorphological features can help distinguish SPNs from other pancreatic neoplasms. Complete surgical resection as well as resection of metastatic disease is preferred given a low rate of tumor recurrence and long periods of disease-free intervals.

Solid pseudopapillary neoplasm of the pancreas: a case report with review of the diagnostic dilemmas and tumor behavior

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of the pancreas often detected initially on imaging. Of uncertain histogenesis, it has a low-grade malignant potential with excellent post-surgical curative rates and rare metastasis. Despite advances in imaging, pseudocysts and other cystic neoplasms feature in the differential diagnosis. Pathological and/or cytological evaluation remains the gold standard in reaching a definitive diagnosis. On morphology alone, other primary pancreatic tumors and metastatic tumors pose a diagnostic challenge. Recent advances in immunohistochemical characterization have made the histopathologic diagnosis more specific and, in turn, shed light on the likely histogenesis of this rare tumor. We report a case of solid pseudopapillary neoplasm of the pancreas that was suspected on radiology and diagnosed intraoperatively on imprint cytology guiding definitive surgery. The diagnostic dilemmas are reviewed.