Endoscopic ultrasound cytologic brushing vs endoscopic ultrasound - fine needle aspiration for cytological diagnosis of cystic pancreatic lesions. A multicenter, randomized open-label trial.

Introduction: the incidence of cystic pancreatic lesions (CPL) in the asymptomatic population is increasing. Achieving a preoperative diagnosis of CPL still remains a challenge.

Objectives: to evaluate the diagnostic accuracy of the cytological diagnosis of CPL from samples obtained by cytology brush versus standard endoscopic ultrasound fine needle aspiration (EUS-FNA).

Methods: a multicenter, randomized, open-label trial was performed of EUS-cytology brush (EUS-EB) versus EUS-FNA for the cytological diagnosis of CPL. Patients that underwent EUS-FNA with a CPL > 15 mm were included and randomized into two groups: group I, EUS-EB; group II, EUS-FNA. The final diagnosis was based on the histological evaluation of surgical specimens and clinical parameters, imaging and a five year follow-up in non-operated patients. The main outcome was the diagnostic accuracy of both methods. Secondary outcomes were the diagnostic adequacy of specimens and the rate of adverse events. Data were compared using the Chi-squared test. An intention to treat (ITT) and per-protocol (PP) analysis were performed.

Results: sixty-five patients were included in the study, 31 in group I and 34 in group II. Three patients initially randomized to group I were changed to group II as it was impossible to obtain a sample using the brush. The mean size of the CPL was 28.2 mm (range 16-60 mm). The diagnostic accuracy of EUS-EB was not superior to EUS-FNA, neither in the ITT nor the PP analysis (44.8% vs 41.1%, p = 0.77 and 38.4% vs 45.9%, p = 0.55).

Conclusions: EUS-EB does not improve the diagnostic accuracy of CPL in comparison with EUS-FNA.