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