Multidisciplinary treatment of advanced or recurrent solid pseudopapillary neoplasm of the pancreas: three case reports

CTNNB1 exon 3 mutations in metastatic solid pseudopapillary neoplasm of the pancreas

BACKGROUND AND OBJECTIVES

Solid pseudopapillary neoplasm (SPN) of the pancreas demonstrates an indolent disease course; however, some patients present with a "malignant" phenotype, including distant metastases resistant to chemotherapy. This analysis identifies molecular drivers of metastatic SPN using the world's largest clinicogenomics database.

METHODS

The American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange was queried for primary and metastatic SPN samples. Sample-level genomic alterations were compared. A pan-pancreatic cancer analysis assessed relevant mutations among all metastatic pancreatic malignancies.

RESULTS

Among 28 SPN samples identified (n = 17 primary, n = 11 metastatic), the most commonly mutated gene was CTNNB1, (24/28 samples; 85.7%). Most mutations were missense (21/24; 87.5%) or in-frame deletions (3/24; 12.5%). The most common CTNNB1 mutations in primary SPN were exon 3 S37F/C missense mutations (6/16 profiled patients, 37.5%), contrasting exon 3 D32N/Y/H missense mutations in metastatic samples (6/11 profiled patients, 54.5%). Metastatic SPN had higher rates of CTNNB1 mutations than metastases from pancreatic ductal adenocarcinoma (72.7% vs. 1.1%; q < 0.0001), pancreatic neuroendocrine tumor (72.7% vs. 2.5%; q < 0.0001), and pancreatic acinar cell carcinoma (72.7% vs. 11.5%; q = 0.0254).

CONCLUSIONS

Missense mutations along exon 3 of CTNNB1 predominate metastatic SPN, differentiating these patients from those with metastases from analogous pancreatic malignancies.

Unresectable Metastatic Solid Pseudopapillary Pancreatic Neoplasm Treated With Liver Transplantation

We present a 49-year-old woman requiring living donor liver transplantation after liver metastasis from a pancreatic solid pseudopapillary tumor. After identifying a pancreatic mass and liver lesions, she underwent extensive surgical resection. Pathology revealed a solid pseudopapillary neoplasm of the head and body of the pancreas, extending into the peripancreatic soft tissues and confirmed to have spread to the liver. Subsequently, she underwent adjuvant chemotherapy and radiofrequency ablations of the new liver lesions. Despite immunotherapy and chemotherapy, there was a progression of the lesions. With interval growth of liver lesions, without evidence of extrahepatic disease, she underwent living donor liver transplantation.

Diagnosis and Management of Pancreatic Cysts

As pancreatic cyst incidence rises, likely due to the ubiquitous increase in cross-sectional imaging, their management presents multiple challenges for both the practitioner and patient. It is critical that all pancreatic cysts are appropriately characterized, as treatment decisions depend on an accurate diagnosis. Diagnostic modalities such as cytology, biopsy, and cyst fluid biomarkers allow for definitive diagnosis of virtually all lesions. Some cysts, such as intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and cystic pancreatic endocrine neoplasms, have malignant potential and must be surveyed. Other cysts, such as serous cystadenomas and pancreatic fluid collections, do not have malignant potential. Surveillance strategies vary widely depending on cyst type and size and while multiple medical societies advocate surveillance, their published surveillance guidelines are heterogenous. Cysts with high-risk stigmata or worrisome features are usually resected, depending on the patient's surgical fitness. In patients unfit for resection, newer endoscopic ablative techniques are advocated. Controversial aspects regarding cyst management include whether surveillance can be stopped, how surveillance should be performed, and the extensive financial burden cyst management places on the health care system. Further study into the natural history of cystic lesions, including definitive determination of the rate of malignant transformation for each cyst type, is essential.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Pediatric Solid Pseudopapillary Neoplasm of the Pancreas

Background

Solid pseudopapillary neoplasm (SPN) of the pancreas in children is a rare tumor with low malignant potential. Some tumors, however, behave aggressively. There is very little literature on managing these variants, especially in children. We share our experience of managing large and recurrent SPN and explore the clinicopathological findings correlating to the risk of recurrence.

Methods

This is a retrospective study of children treated for SPN between 2012 and 2022 at a tertiary care center in India. The clinicopathological features and management strategies in these children were evaluated.

Results

Sixteen children with SPN were treated during this period (88% of girls). The median age of presentation was 12 years (interquartile range [IQR]: 9-14). All children presented with abdominal pain. Computed tomography gave a definitive diagnosis in 81% of cases. The tumor predominantly involved the head of the pancreas (n = 9, 56%). Eight of nine children classified as high-grade (HG) malignant had a benign course. One child had a recurrence of the tumor 4 years after the initial resection and further recurrence on chemotherapy. She required radiation therapy in addition to reoperation following which she was disease free for 77 months. The overall median follow-up was 46 months (IQR: 18-72 months).

Conclusion

Complete resection of the tumor provides a cure in most patients with SPN. Recurrent tumors require a multi-modality approach. Long-term survival is good. There is a need for clear definitions of the components within the WHO criteria for HG malignancy.

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.

The diagnosis and management of solid pseudopapillary epithelial neoplasm of the pancreas in a resource-limited setting: two cases from Cameroon

Solid pseudopapillary epithelial neoplasm (SPEN) of the pancreas is a rare tumor of low malignant potential that occurs most often in young females. Imaging and histopathology are necessary to confirm the diagnosis as most have no symptoms. Lack of access to these technologies in sub-Saharan Africa contributes to the difficulty in making an early and accurate diagnosis, and hence, impedes treatment. We present two cases of SPEN of the pancreas in young female patients at a rural, teaching hospital in Cameroon. The diagnosis was made only with histopathology. Computed tomography scan with intravenous contrast was essential to planning a safe surgical resection. Both patients had complete surgical resection with good results.

Malignant Solid Pseudopapillary Neoplasm of the Pancreas: An Orthogonal Analysis

BACKGROUND

Pancreatic solid pseudopapillary neoplasms (SPN) are generally indolent; however, some patients present with "malignant" SPN. An orthogonal analysis of multiple datasets was performed to investigate the utility of complete surgical resection (CSR) for malignant SPN.

METHODS

A systematic review was performed for cases of malignant SPN, defined as T4, N1, and/or M1. Malignant SPN was analyzed within the National Cancer Database (NCDB) and compared with T1-3N0M0 SPN. Predictors of malignant SPN were assessed, and treatments were analyzed by using survival analysis.

RESULTS

The systematic review yielded 164 cases of malignant SPN. Of 31 children, only one died due to malignant SPN. Among adults, CSR was associated with improved disease-specific survival (DSS) (P = 0.0002). Chemotherapy did not improve malignant SPN DSS, whether resected (P = 0.8485) or not (P = 0.2219). Of 692 adults with SPN within the NCDB, 93 (13.4%) had malignant SPN. Pancreatic head location (odds ratio [OR] 2.174; 95% confidence interval [CI] 1.136-4.166; P = 0.0186) and tumor size (OR 1.154; 95% CI 1.079-1.235; P < 0.0001) associated with the malignant phenotype. Malignant SPN predicted decreased overall survival (OS) compared with T1-3N0M0 disease (P < 0.0001). Resected malignant SPN demonstrated improved OS (P < 0.0001), including resected stage IV malignant SPN (P = 0.0003). Chemotherapy did not improve OS for malignant SPN, whether resected (P = 0.8633) or not (P = 0.5734). Within a multivariable model, resection was associated with decreased hazard of death (hazard ratio 0.090; 95% CI 0.030-0.261; P < 0.0001).

CONCLUSIONS

Approximately 13% of patients with SPN present with a malignant phenotype. Pediatric cases may be less aggressive. Resection may improve survival for malignant SPN, which does not appear chemosensitive.

Frantz's Tumor in Focus: The Tale of a 34-Year-Old Yemeni Female Patient

A solid pseudopapillary tumor (SPT) of the pancreas, which mainly occurs in young women, is an uncommon pancreatic tumor that often presents diagnostic and therapeutic dilemmas. This case study discusses the symptoms and treatment approach for a 34-year-old woman from Yemen diagnosed with SPT. The patient was diagnosed through abdominal and pelvis CT scan, followed by ultrasound-guided biopsy confirming the presence of SPPT. Management through the Whipple procedure and portal vein reconstruction proved successful, with no recurrence or metastasis noted in a year-long follow-up. The importance of comprehensive understanding and surgical expertise in handling SPT is emphasized.

Case report of peritoneal carcinomatosis in the clinical course of pancreatic solid pseudopapillary neoplasm (Frantz's tumor) in a patient with a history of blunt abdominal trauma

INTRODUCTION

Pancreatic solid pseudopapillary neoplasm (SPN), or Frantz's tumor, is a rare tumor with low malignant potential and a high cure rate when treated by complete surgical resection. There have been few reports of metastatic disease as a result of blunt abdominal trauma.

PRESENTATION OF CASE

A 13-year-old female patient was a victim of blunt abdominal trauma in 2019. A computed tomography (CT) scan showed a voluminous hemoperitoneum associated with a tumor in the pancreatic tail whose characteristics suggested a pseudopapillary tumor. The patient remained hemodynamically stable and nonoperative treatment was chosen. Two months later, a CT scan showed resolution of the hemoperitoneum and delimitation of the neoplasm in the tail of the pancreas. Elective body and tail pancreatectomy with laparoscopic splenectomy was performed. The patient remained asymptomatic for 15 months until she developed abdominal pain and constipation. A CT scan suggested peritoneal carcinomatosis, which was confirmed by biopsy of the lesions.

CLINICAL DISCUSSION

A pancreatic SPN, in the context of an abdominal injury, can undergo metastatic progression despite surgical resection with curative intent and adherence to the precepts of minimally invasive oncological surgery. It is important to plan for the long-term follow-up of patients, as well as to understand the risk factors for recurrence.

CONCLUSION

Although pancreatic SPN has a good prognosis, rupture of its capsule due to external trauma, as reported in the present case, may be a mechanism for peritoneal dissemination of the tumor with a consequent reduction in the length of disease-free survival.

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.