Cervical cytology

From patholines.org
Jump to navigation Jump to search

Author: Mikael Häggström [note 1]
Cytology of the cervix:

Clinical information

It is not necessary to look through more than readily available reports from previous cervical cytologies.


While being fairly new to cervical cytology, preferably start looking at a high magnification such as 20x objective (with 10x eye piece). For suspicious findings, you may magnify up to maximum. On the other hand, once the pattern feels repetitive you can try switching to a slightly lower magnification such as 10x.


Adequacy should always be stated, either as "Satisfactory" or "Unsatisfactory". For estimating the number of cells, determine the following:

  • The area of your field of view at high power (see the Evaluation chapter)
  • The total size of the relevant area on the microscope slide. A ThinPrep is about 360 mm2.
  • Look at 10 representative high power fields (HPFs) within that area, and calculate the average number of cells per high power field.
HPF example on a ThinPrep (about 360 mm2). If 10 fields gives a total of 40 cells, it will be 4 cells per HPF. The area of this field is 0.23 mm2. Therefore, total cellularity is estimated to be:
4 cells * 360mm2 / 0.23mm2 = 6260 cells.
Total number of cells = Average number of cells per HPF * Total size of area
HPF area

Conventional smear cellularity should be at least 8,000 cells. Liquid-based cytology cellularity should be at least 5,000 cells. Also a conventional smear is inadequate if >75% of cells are obscured by blood, exudate or air-drying artefact.[1]

Eventually you will be able to tell when most cases are adequate or inadequate without performing a detailed calculation.

Transformation zone presence

Squamous metaplasia also counts as endocervix. Typical features are annotated. Pap stain.

State whether the endocervical/transformation zone is present or absent. Count an endocervical component as present if there are 10 or more endocervical or squamous metaplastic cells.[2]

In patients with previous hysterectomy, simply report glandular or squamous metaplastic cells as such, rather than stating the presence of a transformation zone, since they are likely vaginal in origin in such patients.[3]

Very common findings

Main conditions to exclude or confirm

Squamous atypia, seen mainly as cells with increased nucleus/cytoplasm ratio, nuclear hyperchromasia and irregular nuclear outline.

Cytopathology of squamous cell carcinoma, nonkeratinizing variant, with typical features.[5] Pap stain. Necrotic debris (dirty background) is a feature that generally makes a HSIL case "suspicious for invasive squamous cell carcinoma".[6] In contrast to the more distinct keratinizing variant, these findings are overall less specific, and most can be seen in other cancers such as adenocarcinoma as well (which, however, tends to have fine chromatin)[7]

Clinical implication

If you are uncertain of the degree of dysplasia, it can be useful to look up how much difference it will likely make for the management of the patient. You may make an Internet search for the management of abnormal cervical screening in your region (such as The ASCCP tool for management in the US). A change from close follow-up to colposcopy is not that big of a deal, but if one of the alternatives will lead to a diagnostic excision, make sure that the case is looked upon by commensurate expertise.

Other findings


Example in a normal case:

Cervical/endocervical ThinPrep:
Negative for intraepithelial lesion or malignancy (NILM).


  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page


  1. 1.0 1.1 . Criteria for adequacy of a cervical cytology sample. EuroCytology. Retrieved on 2022-08-29.
  2. Cibas, Edmund S.; Ducatman, Barbara S. (2021). Cytology : diagnostic principles and clinical correlates . Philadelphia, PA. p. 9. ISBN 978-0-323-63637-7. OCLC 1138033641. 
  3. Ramirez NC, Sastry LK, Pisharodi LR (2000). "Benign glandular and squamous metaplastic-like cells seen in vaginal Pap smears of post hysterectomy patients: incidence and patient profile. ". Eur J Gynaecol Oncol 21 (1): 43-8. PMID 10726617. Archived from the original. . 
  4. - Image annotated by Mikael Häggström
    - Reference for entries: Gulisa Turashvili, M.D., Ph.D.. Cervix - Squamous cell carcinoma and variants. Pathology Outlines. Last author update: 24 September 2020. Last staff update: 4 April 2022.
    - Source image from National Cancer Institute (Public Domain)
  5. - Image annotated by Mikael Häggström
    - Reference for entries: Gulisa Turashvili, M.D., Ph.D.. Cervix - Squamous cell carcinoma and variants. Pathology Outlines. Last author update: 24 September 2020. Last staff update: 4 April 2022.
    - Source image by Ravi Mehrotra, Anurag Gupta, Mamta Singh and Rahela Ibrahim (Creative Commons Attribution 2.0 Generic license.)
  6. Alrajjal A, Pansare V, Choudhury MSR, Khan MYA, Shidham VB (2021). "Squamous intraepithelial lesions (SIL: LSIL, HSIL, ASCUS, ASC-H, LSIL-H) of Uterine Cervix and Bethesda System. ". Cytojournal 18: 16. doi:10.25259/Cytojournal_24_2021. PMID 34345247. PMC: 8326095. Archived from the original. . 
  7. Authors: Caroline I.M. Underwood, M.D., Alexis Musick, B.S., Carolyn Glass, M.D., Ph.D.. Adenocarcinoma overview. Pathology Outlines. Last staff update: 19 July 2022

Image sources