Clinical and pathological features of solid pseudopapillary neoplasm (SPN) of the pancreas: A retrospective review of cases at Mayo Clinic.

Abstract

e15757 Background: SPN is a rare neoplasia of the pancreas, defined by the World Health Organization (WHO) as an epithelial low-grade malignant neoplasm, with a high-grade malignant transformation potential. Literature in this subject is scarce and limited only to small retrospective series. Methods: This is a retrospective study aiming to characterize patients with the diagnosis of SPN at Mayo Clinic between 1992 and 2016. Demographics, clinical and pathological features, recurrence rate and overall survival were recorded. Malignant SPN was defined as per the WHO 2010 classification (Perineural invasion, angioinvasion or deep tissue invasion) and compared to Benign SPN. Results: 44 patients with SPN were identified. 39 patients (88.6%) were female. Median age at diagnosis was 27.5 (Range: 13-64). The most frequent presentation was abdominal pain (52.6%), whereas 36.8% were diagnosed based on incidental imaging findings. Majority (60.4%) of the tumors were located at the pancreatic tail, and 48.5% were solid-cystic lesions. Vascular and lymph node involvement were infrequent. 15 cases (30.23%) were classified as malignant. Tumor size was associated with malignant behavior (Table). Three patients had a metastatic presentation. All but 1 patient were treated with surgery. R1 resection was more frequent in malignant SPN, and 2 patients experienced disease recurrence. Two Stage IV patients were treated with surgery and experienced long term survival, one of them without evidence of disease. There was only 1 death recorded. Conclusions: SNP presents predominantly on young women. The prognosis is excellent even in presence of malignant features, and a complete surgery remains as the main treatment. [Table: see text]