Endoscopic ultrasound-guided fine needle aspiration improves the pre-operative diagnostic yield of solid-pseudopapillary neoplasm of the pancreas: an international multicenter case series (with video).

BACKGROUND/
OBJECTIVES: Solid-pseudopapillary neoplasms (SPNs) are rare pancreatic tumors, which occur most frequently in young women and are associated with an excellent prognosis. Computed tomography (CT) is used most commonly to identify these lesions, but there are few studies evaluating the role of endoscopic ultrasound (EUS) and fine needle aspiration (EUS-FNA) in the assessment of SPN. The aim of the study was to determine the incremental diagnostic yield of EUS-FNA compared with CT or EUS in the evaluation of patients with SPN.
METHODS: A retrospective chart review of consecutive patients diagnosed with SPN who underwent CT, EUS, and EUS-FNA at five centers from three countries from 1998 to 2013. Patient demographics, imaging, endoscopic studies, cytopathology, and histology were reviewed.
RESULTS: Thirty-four patients were identified with SPN. There were 31 (91.2 %) females, with a mean age at diagnosis of 37 years (range 16-81). The most common presenting symptom was abdominal pain which was present in 59 %. SPNs were incidentally detected in 14 (41.2 %) of the patients. The median tumor size was 4.2 cm (range 1.9-9.4). No patient had evidence of local or distant metastases. The most common appearance on EUS was of a mixed solid-cystic lesion (67.6 %). The diagnostic yield of CT and EUS alone was 23.5 and 41.2 %, respectively. CT and EUS combined had a diagnostic yield of 52.9 %. The addition of EUS-FNA significantly increased the diagnostic yield to 82.4 % compared with either CT or CT and EUS (p < 0.005). There were no reported adverse events reported.
CONCLUSIONS: SPNs are rare pancreatic tumors primarily affecting young women. The addition of EUS-FNA significantly increased the pre-operative diagnostic yield of SPN to 82.4 %.