Cervical Cytology Sampling

There are 2 methods for preparing a specimen for cervical cytology: liquid-based cytology (e.g., ThinPrep) and conventional pap smears. For both methods, cells are obtained from the external surface of the cervix (ectocervix) and the cervical canal (endocervix) to evaluate the transformation zone (squamocolumnar junction), the area at greatest risk for neoplasia. It’s important to recognize that obtaining endocervical cells helps ensure adequate sampling of the transformation zone. 

Several collection devices are available, and there are multiple types of each device used in practice around the world. The most commonly recommended devices are spatulas (e.g., Ayre spatula), endocervical brushes (e.g., Cytobrush), and broom devices (e.g., Papette). In general, the spatula and endocervical brush are used in sequence (spatula followed by endocervical brush) whereas the broom device is used alone, as pictured below. 

Protocol with spatula and endocervical brush:

Source: Hologic

Protocol with broom device:

Source: Hologic

Evidence is very limited on which approach is best, in part complicated by the sheer number of devices on the market. A 2000 Cochrane review found that the combination spatula+brush was likely superior whereas a recent 2023 study did not find any significant difference between the two approaches (i.e., spatula+brush versus broom device). 

Sample collection: 

  • Spatula: Rotate the spatula 360º around the ectocervix.
    • Sampling the ectocervix before the endocervix (i.e., using the spatula prior to the endocervical brush) minimizes bleeding. Blood in the sample may interfere with cytology interpretation.
    • Plastic spatulas (vs wood) are preferred for liquid-based samples. 
  • Brush: Insert the endocervical brush into the endocervix so that the bristles nearest the examiner are inserted to the level of the external os. Rotate the brush 90-180º to obtain a sample.
    • Rotating more than 180º is unnecessary and more likely to cause bleeding.
  • Broom device: Insert the central bristles of the broom device into the endocervix with the outer bristles in contact with the ectocervix. Rotate the broom for five 360º clockwise turns.
    • The broom is designed to capture cells when rotated clockwise; counterclockwise rotation can cause cells to slough, but does not trap them in the broom. 
    • Certain broom devices only require 2-3 turns, but the type we have in our clinic requires 5 turns.
Scroll to Top