Adequacy of the sample

Author: Andreia Carreira. See authors page.
Last edited: Pathologika, January 30, 2016.
Cite this page: Carreira, A., Adequacy of the sample – Pathologika. Available at: https://pathologika.com/citologia/citologia-cervico-vaginal/bethesda-2001/adequacao-da-amostra/ [Accessed: date].

In order to evaluate the adequacy of the cytology sample it should contain a sufficient number of epithelial cells. According to Bethesda 2001, it is recommended that Pap smears be classified as “Satisfactory for evaluation” or “Unsatisfactory for evaluation

SATISFACTORY FOR EVALUATION

For a sample to be classified as “Satisfactory for Evaluation”, it must contain at least 5,000 well-conserved epithelial cells in liquid cytology samples and 8,000 to 12,000 well-preserved epithelial cells in conventional cytology samples.

No matter what, any cytology sample with abnormal cells should be considered satisfactory for evaluation, regardless of the number of epithelial cells present.

A cervical cytology sample must contain at least 10 well preserved endocervical or metaplastic cells (transformation zone). However, if the sample does not contain at least 10 well preserved endocervical or metaplastic cells should not be considered as unsatisfactory; this fact brought the need to classify the sample as: “with representation of the transformation zone” and “without representation of the transformation zone”. The existence of the transformation zone is very important to see if the harvest was well done, since it is in this zone that almost all manifestations of cervical carcinogenesis occur.

How to estimate the total cellularity of a cervico-vaginal cytology smear?

1. Minimum mean number of cells per observed field, to have 5000 cells in the smear: Number of cells required per field = 5000 / (circle area / eyepiece area)

2. Calculation of the microscopic field diameter (mm):
Microscopic field diameter (mm) = FN / lens value
Where FN is the measurement of the eyepiece diameter of the microscope to be used

3. Calculating the area of a circle:

A= π*r2
π=3.1416; r= ray

Tabela C3 - Exemplo do número médio de células por campo microscópico para a presença de 5000 células nas lâminas de citologia em meio líquido.

Table C3 – Example of the mean number of cells per microscopic field for the presence of 5,000 cells in the cytolysis slides in liquid medium.

Tabela C4 – Exemplo do número médio de células por campo microscópico para a presença de 8000 células nas lâminas de citologia convencional.

Table C4 – Example of the average number of cells per microscopic field for the presence of 8000 cells in the slides of conventional cytology.

UNSATISFACTORY FOR EVALUATION

A sample that has been processed and analyzed may be considered unsatisfactory for diagnosis due to several factors, namely:
1. insufficient number of cells,
2. obscuration (in more than 75% of cells) by blood / drying (airborne) / excess cytolysis / lubricant / mucus / excess inflammatory cells.

The reason for a sample being characterized as unsatisfactory should be specified. When a sample is between 50 and 75% obscured by blood, it should be classified as satisfactory but with a note describing the limitation of observation of the entire sample.

No matter what, any cytology sample with abnormal cells should be considered satisfactory for evaluation, regardless of the number of epithelial cells present or any other limitation factor.