Solid pseudopapillary tumor of the pancreas: ‘Experiences’ and ‘Lessons’ at a tertiary-care oncology center

Cytological Diagnosis of Pancreatic Solid-Pseudopapillary Neoplasm: A Single-Institution Community Practice Experience

Introduction. Pancreatic solid-pseudopapillary neoplasm (SPN) is a rare tumor that typically occurs in young females. Although a cytological diagnosis may be easily made in this age group when there are typical features, atypical clinical presentations and unusual cytological features may make this a challenging diagnosis. We present our single-institution experience in a cohort of these tumors, outlining both typical and atypical features. Awareness of unusual clinical and cytological features can help to avoid pitfalls during diagnosis. Methods. We performed a review of all cases of pancreatic SPNs diagnosed over a 15-year period (January 2007 to December 2021). Detailed cytological, clinical, and follow-up histological features were presented and analyzed. Results. Twenty-two cases of SPN were diagnosed at our institution during this 15-year period. Patients ranged from 12 to 73 years of age (mean 33 y, median 26 y) and included 19 females and 3 males. Seventeen patients had cytological material, and fourteen were diagnosed by EUS-FNA. Typical cytological features included papillary clusters with central capillaries, myxoid stroma, monomorphism, cercariform cells, and hyaline globules. Atypical or unusual cytological features that were seen in a few cases were multinucleated giant cells, clear cells, and/or foamy macrophages. A few cases showed features that were similar to pancreatic neuroendocrine tumors (PanNETs). Tumor cells were always positive for β-catenin, CD10, CD56, cyclin-D1, progesterone receptor (PR), and vimentin by immunohistochemistry. They were always negative for chromogranin. Pancytokeratin and synaptophysin stains were positive in 9% and 46% of cases evaluated, respectively. All cases had histological confirmation on resection. The median follow-up duration was 69 months (a range of 2–177 months), with only three cases lost to follow-up. No recurrence or metastasis was identified. Conclusions. We present our experience with cytological diagnoses of SPN in a well-characterized cohort of 22 patients with histological correlation and follow-up data. These tumors occur over a wide range and show varied cytological features. SPNs can be confidently diagnosed on limited cytological material, with limited panel immunohistochemistry aiding diagnosis in atypical cases. Recognizing the associated degenerative changes is crucial in avoiding a misdiagnosis.

Outcome after surgery for solid pseudopapillary pancreatic tumors in children: Report from the TREP project-Italian Rare Tumors Study Group

BACKGROUND

Solid pseudopapillary pancreatic tumors (SPPT) are an extremely rare entity in pediatric patients. Even if the role of radical surgical resection as primary treatment is well established, data about follow-up after pancreatic resection in children are scant.

METHODS

A retrospective review of data from the Italian Pediatric Rare Tumor Registry (TREP) was performed. Short-term (<30 days) and long-term complications of different surgical resections, as well as long-term follow-up were evaluated.

RESULTS

From January 2000 to present, 43 patients (male:female = 8:35) were enrolled. The median age at diagnosis was 13.2 years (range, 7-18). Nine children had an incidental diagnosis, whereas 26 complained of abdominal pain and 4 of palpable mass. Tumors arose either from the head of pancreas (n = 14) or from body/tail (n = 29): only one patient presented with metastatic disease. Resection was complete in all patients (cephalic duodenopancreatectomy vs distal resection). At follow-up (median, 8.4 years; range, 0-17 years), one recurrence occurred in a patient with intraoperative rupture. All patients are alive. Three pancreatic fistulas occurred in the body/tail group, whereas four complications occurred in the head group (one ileal ischemia, two stenosis of the pancreatic duct, and one chylous fistula).

CONCLUSION

Surgery is the best therapeutic option for these tumors; hence, complete resection is mandatory. Extensive resections, including cephalic duodenopancreatectomy, are safe when performed in specialized centers. Long-term follow-up should be aimed to detect tumor recurrence and to evaluate residual pancreatic function.

Cytologic criteria to reduce error in EUS-FNA of solid pseudopapillary neoplasms of the pancreas

INTRODUCTION

Standardization of error classification in pathology remains an important issue. This study assesses the extent of error in cytopathologic diagnosis of solid pseudopapillary neoplasms (SPN) of the pancreas. Because of morphologic overlap of SPN and pancreatic neuroendocrine neoplasms (NET), we compared cytologic characteristics to determine which best distinguishes these entities.

MATERIALS AND METHODS

We collected cases diagnosed as SPN either by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) by cytology or surgical pathology from January 2000 to March 2013. An equal number of NET cases were randomly selected. Cytology and surgical pathology cases were evaluated for diagnostic errors and patient impact. Cytologic features in SPN and NET were scored based on presence of previously described characteristics.

RESULTS

A total of 17 patients with EUS-FNA were diagnosed with SPN by cytology or surgical pathology. Of those, 14 had surgical follow-up and 13 had adequate cell blocks and immunohistochemistry. There were 5 discrepancies between cytology and surgical pathology (5 of 14, 36%). There were no false positives or false negatives, but 5 misclassifications: 4 diagnosed as NET on cytology, and 1 as NET versus SPN. All misclassification errors were associated with no harm. When compared with NET, fine chromatin, nuclear grooves, pseud papillae, pink stroma, and hyaline globules are statistically significantly associated with SPN.

CONCLUSIONS

EUS-FNA of pancreatic SPN has excellent positive and negative predictive value, with no false positives or false negatives in this 12-year study. Only misclassification errors as pancreatic NET were made with minimal impact. We suggest that the presence of 3 of 5 major cytologic criteria offer accuracy in diagnosing SPN to prevent misclassification.

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.

Surgical treatment of solid pseudopapillary neoplasms of the pancreas and risk factors for malignancy

BACKGROUND

The aim of this study was to identify clinical predictors of malignancy and surgical strategies for pancreatic solid pseudopapillary neoplasm (SPN) by analysis of surgical outcomes at a single institution.

METHODS

All patients who underwent surgery for SPN between 1995 and 2010 were identified. Histopathology slides of all patients were reviewed by a specialized pathologist and the neoplasms were classified according to the criteria of the World Health Organization 2010.

RESULTS

Of the 106 patients identified, 85 (80·2 per cent) were female, and the median age was 36 (range 10-65) years. Median tumour size was 4·5 (range 1·0-15·0) cm. Some 17 patients (16·0 per cent) were classified as having a high-grade malignant SPN. Tumour size of at least 5 cm was associated with high-grade malignant potential (P = 0·022). Although lymph nodes were removed from 40 patients (37·7 per cent), there were no nodal metastases. A total of five patients underwent en bloc resection of adjacent structures, including two with portal vein involvement. After a median follow-up of 56·9 months, two patients with high-grade malignant SPN had evidence of tumour recurrence in the lymph nodes and liver.

CONCLUSION

SPN with a diameter of 5 cm or more is associated with a high-grade malignant phenotype. Complete surgical removal is associated with low recurrence rates.