Adequacy of cervical cytology by The Bethesda System cell number in specimens in cervical cancer mass screening

Objective : The Bethesda System (TBS) defines specimen adequacy. Study Design : We analyzed TBS adequacy by mass-screening 69,584 smears to compare the unsatisfactory TBS rate to that by conventional criteria. Conventional criteria were defined as self-made items that were unsatisfactory but evaluable. We verified criteria appropriateness using the result of a to follow-up study of participants. We defined the number of cells adequate, i. e. evaluable although unsatisfactory in mass-screening, as a central value of a minimum of 500 cells. Result : We found 77 unsatisfactory specimens in conventional criteria and 590 unsatisfactory specimens by TBS criteria. The unsatisfactory rate of 0.85% in TBS criteria was significantly higher than that of 0.11% in conventional criteria. The follow-up study of participants showed proved no serious misdiagnosis with specimens as defined in this paper. Conclusions : The strict indication of TBS criteria in mass-screening is not practical. Our criteria as defined, i. e. a central value of a minimum 500 cells, to avoid an increase in the unsatisfactory rate, we should define unsatisfactory but evaluable specimens more satisfactorily.