Rapid on-site evaluation (ROSE) versus macroscopic on-site evaluation (MOSE) for endoscopic ultrasound-guided sampling of solid pancreatic lesions: a paired comparative analysis using newer-generation fine needle biopsy needles.

Background: Rapid on-site examination (ROSE) during endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) has been a subject of debate. We compared the yield of EUS-FNB with adequacy assessed using macroscopic on-site evaluation (MOSE), and smear cytology with adequacy confirmed by ROSE, acquired using the same needle.

Methods: Consecutive patients with solid pancreatic lesions (SPLs) who underwent EUS-FNB of pancreatic solid lesions between January 2021 and July 2022 were included. Demographic details, site and size of lesion, number of passes, and the diagnosis by cytology and histopathology of core tissue were noted. The first pass was used for ROSE adequacy assessment and was subsequently sent for cytological assessment. Additional passes were taken subsequently to acquire core tissue. Adequacy was confirmed by MOSE (whitish core of more than 4 mm). Final cytology and histopathology (HPE) were compared for diagnostic accuracy.

Results: One hundred fifty-five patients were included in the analysis during the study period (mean age 55.1+12.9 years; 60% male; 77% in pancreatic head; median size 3.7 cm). The final diagnosis was malignancy in 129, while 26 were negative for malignancy. Sensitivity and specificity for ROSE with cytology in detecting malignant SPLs were 96.9% and 100%, respectively. HPE with MOSE had sensitivity and specificity of 96.1% and 100%, respectively. A comparison of diagnostic accuracy showed no significant difference (P>0.99) between HPE with MOSE and ROSE with cytology, using an FNB needle.

Conclusion: MOSE is as good as ROSE in terms of diagnostic yield for solid pancreatic lesions sampled using newer-generation EUS biopsy needles.