Abstract
BACKGROUND: Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) is the primary method of sampling pancreatic cystic lesions with reported specificity near 100% for diagnosing malignancy. Discrepant positive malignant cytopathology with final surgical pathology of pancreatic cystic lesions has not previously been described. AIMS: To present a case series and review the literature regarding the implications of positive malignant cytology with discrepant surgical pathology for high risk pancreatic mucinous cystic lesions. METHODS: Patient demographics, clinical history, procedure details, pathology evaluations and follow-up were collected. A thorough literature review was performed. RESULTS: Three patients with high-risk pancreatic cystic lesions on cross-sectional imaging underwent EUS-FNA evaluation. None of these patients had a history of pancreatitis. Cytology was reported as positive for adenocarcinoma in all patients by separate gastrointestinal cytopathologists. All patients underwent surgical resection. The pathology for all resected specimens were reported as intraductal papillary mucinous neoplasm. The resected cysts for two patients demonstrated foci of high-grade dysplasia and the third noted low grade dysplasia. All surgical pathology underwent consensus review by three separate gastrointestinal pathologists. None of the patients were treated with adjuvant chemotherapy. All patients have been followed post-operatively with surveillance magnetic resonance imaging with no evidence of recurrence to date (median follow-up time 239 days, range 133 – 447 days). CONCLUSIONS: This phenomenon sheds light on the potential for variable interpretations of EUS-FNA cytopathology and surgical resection pathology for high risk pancreatic cystic neoplasms. EUS-FNA may identify foci of adenocarcinoma that is not seen on surgical pathology specimens. Further research is required to examine the long-term outcomes of these patients. FUNDING AGENCIES: None