Telecytology validation: is there a recipe for everybody?

•A standardized approach to telecytology validation studies is presented.•A retrospective case mix comparable to real life was included after a 6-month wash-out period.•All cytopathologists were exposed to the same images at the same time, using a dynamic digital pathology tool.•The study was conducted in 2 steps where a small number of cases were used for the “training” phase, and a larger number of cases were used for “validation”.•Overall concordance rate among 4 cytopathologists was 94.8% for adequacy, not crediting any discrepancies.•Overall concordance rate among 4 cytopathologists was 91.9% for diagnostic category, not crediting any discrepancies.