Introduction: Rapid onsite evaluation (ROSE) generally uses smears made at the site of the procedure ("smear-based ROSE"). It requires considerable time, generally 2 individuals, technical expertise, and it can be difficult to estimate material available for ancillary studies. We developed an alternative ROSE using liquid-based cytology ThinPrep with hematoxylin and eosin (H&E) stain ("liquid-based ROSE") and assessed its advantages.

Materials and methods: Clinicians rinse the sample(s) into CytoRich Red and send to Pathology. A defined proportion of the needle rinse is removed for a ThinPrep stained with a rapid H&E. Adequacy and diagnosis were compared to final outcome. Total time was recorded.

Results: Among 52 liquid-based ROSE readings, 28 (53.8%) were interpreted as "adequate" with final as adequate; 17 (32.7%) were interpreted as "inadequate" with final as inadequate; 7 (13.5%) were interpreted as "inadequate" with final as adequate. Of 23 readings provided with onsite diagnosis, 15 (65.2%) were interpreted as definitive positive or negative diagnoses; 6 (26%) were interpreted as nondiagnostic; and 2 (8.7%) were interpreted as atypical. All definitive diagnoses were concordant with final diagnoses. The time for liquid ROSE performance ranges from 6 to 22 minutes (mean: 13 minutes) and required only 1 individual.

Conclusions: Liquid-based ROSE allows accurate adequacy determination and diagnosis, takes about 15 minutes of cytologist time, and can be performed by just 1 person. The technique produces well-preserved and stained slides, it may allow a better estimation of the total amount of material in the specimen vial and may provide a better platform for telecytology.