Rapid on-site evaluation of EUS-FNA by cytopathologist: an experience of a tertiary hospital.

Endoscopic ultrasound-guided-fine-needle aspiration (EUS-FNA) is the preferred modality nowadays for the cytological diagnosis of various mediastinal and gastrointestinal lesions. Onsite cytopathology interpretation is not available in most centers. The objective of this study is to assess whether rapid on-site evaluation (ROSE) by cytopathologist of the tissue samples improves the diagnostic accuracy of EUS-FNA. This study is a retrospective review of all 646 patients undergoing EUS-FNA between January 2009 and October 2012 in our hospital. Patients in group I had cytology slides prepared by an endoscopy nurse. Patients in group II had cytology slides prepared, stained and assessed for adequacy of tissue sampling by a cytopathologist onsite. The adequacy of the samples and the final cytopathological diagnosis (definitely positive, definitely negative, inconclusive, or inadequate) was compared between the two groups. A total of 425 EUS-FNA procedures were performed in 375 patients in group I and 271 EUS-FNA procedures in 271 patients in group II. The mean of needle passes in group I was 3.12 passes per patient and 3.24 passes in group II. The difference in the number of needle passes was not statistically significant (P = 0.30). The final diagnosis was definite in 64.8% in group I compared with 97.7 % in group II (P = 0.001). The percentage of inconclusive and inadequate diagnoses was 5.6% and 29.3%, respectively in group I and 0% and 2.3% in group II (P = 0.001). In conclusion, ROSE by cytopathologist and interpretation significantly improves the diagnostic yield of EUS-FNA.