The cytological component of cervical cancer screening: causes of false negative and false positive results, and ways to avoid them


  • O.A. Burka Bogomolets National Medical University; “DILA” Medical Laboratory, Ukraine
  • N.F. Lygyrda National Cancer Institute, Ukraine
  • V.V. Kutsovol “DILA” Medical Laboratory, Ukraine
  • A.V. Svintsitska National Cancer Institute, Ukraine



Pap test, liquid cytology, atypia, atrophy, reactive changes, reparative changes


Cervical cancer (CC) screening is a major component of secondary prevention of CC and involves screening all women at risk of developing this disease, most of whom are asymptomatic. Cytology remains an important component of CC screening in the era of primary screening by genotyping the human papillomavirus. Papanikolaou staining is the method of choice for CC screening. This review highlights the causes of false negative results for various methods of Pap tests and how they can be prevented. A detailed analysis of conditions accompanied by a high probability of false positive abnormal results of the Pap test, an explanation of the pathophysiological basis of this phenomenon, clinical and cytological criteria for differential diagnosis is also presented.
Pap test is a screening test. The aim of the cytological examination in CC screening is to assign the patient to a group with absent neoplastic changes in the cervical epithelium, a group with neoplastic changes in the cervical epithelium present, or a group when it is impossible to make an accurate differential diagnosis between benign reactive changes and neoplasia. The Bethesda Cytology Reporting System is used to unify and standardize these categories in most countries of the world. Benign conditions are a common cause of false positive reports of cellular atypia on cervical screening, as evidenced by a large number of studies. This fact should be taken into account both in the interpretation of the results and, if possible, in the planning of cervical screening. The most common conditions that are accompanied by reactive changes in the cervical epithelium, which can be incorrectly assessed as atypia, are: reactive and reparative inflammatory changes, atrophy, metaplasia, reactive changes caused by intrauterine devices. In this regard, when working with the cytological component of cervical screening, it is important for the clinician to understand the basic principles of assessing the cervical epithelium, which will allow using the descriptive part of the report to determine tactics if a false negative or false positive screening result is suspected.
Thus, understanding the impact of common benign conditions on the cervical epithelium makes it possible to rationally plan cytological cervical screening and correctly interpret its results in order to achieve the best clinical results that are not limited to the detection of precancerous conditions.

Author Biographies

O.A. Burka, Bogomolets National Medical University; “DILA” Medical Laboratory

PhD, associate professor at the Obstetrics and Gynaecology Department No. 1;

Scientific consultant

N.F. Lygyrda, National Cancer Institute

PhD, leading researcher

V.V. Kutsovol, “DILA” Medical Laboratory

Cytological laboratory’s chief manager

A.V. Svintsitska, National Cancer Institute

Gynecological oncologist, outpatient department


  1. Ogilvie, G., Nakisige, C., Huh, W.K., et al. “Optimizing secondary prevention of cervical cancer: Recent advances and future challenges.” Int J Gynecol Obstet 138 (2017): 15–9. DOI: 10.1002/ijgo.12187
  2. World Health Organization; Cervical cancer elimination initiative. Global strategy to accelerate the elimination of cervical cancer as a public health problem (2020). Available from: [], last accessed March 17, 2021.
  3. Perkins, R.B., Guido, R.L., Saraiya, M., et al. “Summary of Current Guidelines for Cervical Cancer Screening and Management of Abnormal Test Results: 2016–2020.” J Women’s Heal 30 (2021): 5–13. DOI: 10.1089/jwh.2020.8918
  4. Chrysostomou, A., Stylianou, D., Constantinidou, A., Kostrikis, L. “Cervical Cancer Screening Programs in Europe: The Transition Towards HPV Vaccination and Population-Based HPV Testing.” Viruses 10 (2018): 729. DOI: 10.3390/v10120729
  5. Bhatla, N., Singhal, S.“Primary HPV screening for cervical cancer.” Best Pract Res Clin Obstet Gynaecol 65 (2020): 98–108. DOI: 10.1016/j.bpobgyn.2020.02.008
  6. von Karsa, L., Dillner, J., Suonio, E., et al. European guidelines for quality assurance in cervical cancer screening. Second edition: Supplements (2015). DOI: 10.2875/93363
  7. Perkins, R.B., Guido, R.S., Castle, P.E., et al. “2019 ASCCP Risk-Based Management Consensus Guidelines for Abnormal Cervical Cancer Screening Tests and Cancer Precursors.” J Low Genit Tract Dis 24 (2020): 102–31. DOI: 10.1097/LGT.0000000000000525
  8. Perkins, R.B., Austin, R.M., Zhao, C., et al. “What Role Should Cytology Play in Cervical Cancer Screening?” J Low Genit Tract Dis 23 (2019): 205–9. DOI: 10.1097/LGT.0000000000000479
  9. Tambouret, R.H., Wilbur, D.C. “The many faces of atrophy in gynecologic cytology.” Clin Lab Med 23 (2003): 659–79. DOI: 10.1016/S0272-2712(03)00059-3
  10. Kaufman, H.W., Alagia, D.P., Chen, Z., et al. “Contributions of Liquid-Based (Papanicolaou) Cytology and Human Papillomavirus Testing in Cotesting for Detection of Cervical Cancer and Precancer in the United States.” Am J Clin Pathol 154 (2020): 510–6. DOI: 10.1093/ajcp/aqaa074
  11. Torous, V.F., Pitman, M.B. “Interpretation pitfalls and malignant mimics in cervical cytology.” J Am Soc Cytopathol (2020). DOI: 10.1016/j.jasc.2020.06.005
  12. Stoler, M.H., Jenkins, D., Bergeron, C. “The pathology of cervical precancer and cancer and its importance in clinical practice.” In: Human Papillomavirus Proving Using a Viral Cause Cancer. Elsevier (2019): 85–109. DOI: 10.1016/B978-0-12-814457-2.00006-4
  13. Zhang, X., Brister, K. “Overview of Cervical and Anal Cytopathology.” In: Pract. Cytopathol. Springer International Publishing (2020): 27–41. DOI: 10.1007/978-3-030-24059-2_3
  14. Clinical Laboratory Standards Institute. GP15-A3 Cervicovaginal Cytology Based on the Papanicolaou Technique; Approved Guideline-Third Edition (2008). Available from: [], last accessed Feb 11, 2021.
  15. Rao, R. Comparison of liquid based cytology with conventional Papanicolaou method in screening of Pap smears.” Int J Med Sci Diagnosis Res 3 (2019): 39–43. DOI: 10.32553/IJMSDR/v3i7.10
  16. American College of Obstetricians and Gynecologists. “ACOG practice bulletin No. 99: Management of abnormal cervical cytology and histology.” Obstet Gynecol 112 (2008): 1419–44. DOI: 10.1097/AOG.0b013e318192497c
  17. Gibb, R.K., Martens, M.G. “The impact of liquid-based cytology in decreasing the incidence of cervical cancer.” Rev Obstet Gynecol 4 (2011): S2–S11. Available from: [], last accessed Feb 11, 2021.
  18. Díaz-Rosario, L.A., Kabawat, S.E. “Performance of a fluid-based, thin-layer Papanicolaou smear method in the clinical setting of an independent laboratory and an outpatient screening population in new England.” Arch Pathol Lab Med 123 (1999): 817–21. DOI: 10.5858/1999-123-0817-poafbt
  19. Beerman, H., van Dorst, E.B.L., Kuenen-Boumeester, V., Hogendoorn, P.C.W. “Superior performance of liquid-based versus conventional cytology in a population-based cervical cancer screening program.” Gynecol Oncol 112 (2009): 572–6. DOI: 10.1016/j.ygyno.2008.12.012
  20. Kamarunisha, A.K., Shariff, M.H. “A comparative study of conventional pap smear with liquid based cytology for early diagnosis of cervical cancer.” IP Arch Cytol Histopathol Res 5 (2020): 141–6. DOI: 10.18231/j.achr.2020.029
  21. Austin, R.M., Onisko, A., Zhao, C. “Enhanced Detection of Cervical Cancer and Precancer Through Use of Imaged Liquid-Based Cytology in Routine Cytology and HPV Cotesting.” Am J Clin Pathol 150 (2018): 385–92. DOI: 10.1093/ajcp/aqy114
  22. Haghighi, F., Ghanbarzadeh, N., Ataee, M., et al. “A comparison of liquid-based cytology with conventional Papanicolaou smears in cervical dysplasia diagnosis.” Adv Biomed Res 5 (2016): 162. DOI: 10.4103/2277-9175.192735
  23. Hoda, R.S., VandenBussche, C., Hoda, S.A. “Liquid-Based Specimen Collection, Preparation, and Morphology.” In: Diagnostic Liquid-Based Cytology. Springer Berlin Heidelberg (2017): 1–12. DOI: 10.1007/978-3-662-53905-7_1
  24. Fontaine, D., Narine, N., Naugler, C. “Unsatisfactory rates vary between cervical cytology samples prepared using ThinPrep and SurePath platforms: A review and meta-analysis.” BMJ Open 2 (2012). DOI: 10.1136/bmjopen-2012-000847
  25. Rozemeijer, K., Naber, S.K., Penning, C., et al. “Cervical cancer incidence after normal cytological sample in routine screening using SurePath, ThinPrep, and conventional cytology: Population based study.” BMJ 356 (2017). DOI: 10.1136/bmj.j504
  26. Arbyn, M., De Cock, R. Cervical cancer screening in the flemish community. A technical guideline: collection of adequate PAP smears of the uterine cervix. Available from: [], last accessed Mar 17, 2021.
  27. Jeong, H., Hong, S.R., Chae, S.W., et al. “Comparison of unsatisfactory samples from conventional smear versus liquid-based cytology in uterine cervical cancer screening test.” J Pathol Transl Med 51 (2017): 314–9. DOI: 10.4132/jptm.2017.03.17
  28. Colgan, T.J., Woodhouse, S.L., Styer, P.E., et al. “Reparative changes and the false-positive/false-negative Papanicolaou test: A study from the college of American pathologists interlaboratory comparison program in cervicovaginal cytology.” Arch Pathol Lab Med 125 (2001): 134–40. DOI: 10.5858/2001-125-0134-RCATFP
  29. Arbyn, M., Herbert, A., Schenck, U., et al. European guidelines for quality assurance in cervical cancer screening: recommendations for collecting samples for conventional and liquid-based cytology (2007). DOI: 10.1111/j.1365-2303.2007.00464.x
  30. Nayar, R., Wilbur, D.C. The bethesda system for reporting cervical cytology: Definitions, criteria, and explanatory notes. Springer International Publishing (2015). DOI: 10.1007/978-3-319-11074-5
  31. Izadi-Mood, N., Sarmadi, S., Alijani, S., Sanii, S. “The significance of hyperkeratosis in pap smears with squamous intraepithelial lesion.” Acta Cytol 56 (2012): 379–82. DOI: 10.1159/000337453
  32. Kobayashi, T.K., Okamoto, H. “Cytopathology of Pregnancy-Induced Cell Patterns in Cervicovaginal Smears.” Pathol Patterns Rev 114 (2000): S6–S20. DOI: 10.1093/ppr/114.1.s6
  33. Draganova-Tacheva, R., HooKim, K. “Normal and Benign Cervical Cytology.” In: Practical Cytopathology: Frequently Asked Questions. Springer International Publishing (2020): 43–57. DOI: 10.1007/978-3-030-24059-2_4
  34. Carneiro, F.P., Darós, A.C., et al. “Cervical Cytology of Samples with Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma hominis, and Neisseria gonorrhoeae Detected by Multiplex PCR.” Biomed Res Int 2020 (2020). DOI: 10.1155/2020/7045217
  35. Fitzhugh, V.A., Heller, D.S. “Significance of a Diagnosis of Microorganisms on Pap Smear.” J Low Genit Tract Dis 12 (2008): 40–51. DOI: 10.1097/lgt.0b013e31813e07ff
  36. Elgert, P.A., Yee-Chang, M., Simsir, A. “Cytomegalovirus (CMV) in cervical cancer screening tests: A series of 8 cases and review of the literature.” Diagn Cytopathol 46 (2018): 593–9. DOI: 10.1002/dc.23951
  37. Manek, S., Dhar, S. “Infections in the gynaecological tract.” Diagnostic Histopathol 19 (2013): 62–6. DOI: 10.1016/j.mpdhp.2013.01.008
  38. Duguid, H., Duncan, I., Parratt, D., Traynor, R. “Actinomyces and Intrauterine Devices.” JAMA 248 (1982): 1579. DOI: 10.1001/jama.1982.03330130027014
  39. Jahic, M., Jahic, E. “Diagnostic Approach to Patients with Atypical Squamous Cells of Undetermined Significance Cytologic Findings on Cervix.” Med Arch (Sarajevo, Bosnia Herzegovina) 70 (2016): 296–8. DOI: 10.5455/medarh.2016.70.296-298
  40. Paba, P., Criscuolo, A.A., et al. “Microbiological Infections in Women With Cervical Cytological Reports of Atypical Squamous Cells of Undetermined Significance.” J Low Genit Tract Dis 19 (2015): 203–6. DOI: 10.1097/LGT.0000000000000078
  41. Vieira-Baptista, P., Lima-Silva, J., Pinto, C., et al.“Bacterial vaginosis, aerobic vaginitis, vaginal inflammation and major Pap smear abnormalities.” Eur J Clin Microbiol Infect Dis 35 (2016): 657–64. DOI: 10.1007/s10096-016-2584-1
  42. Donders, G.G.G., Depuydt, C.E., Bogers, J.-P., Vereecken, A.J. “Association of Trichomonas vaginalis and Cytological Abnormalities of the Cervix in Low Risk Women.” PLoS One 8 (2013): e86266. DOI: 10.1371/journal.pone.0086266
  43. Donders, G.G.G., Ruban, K., Bellen, G., Grinceviciene, S. “Pharmacotherapy for the treatment of vaginal atrophy.” Expert Opin Pharmacother 20 (2019): 821–35. DOI: 10.1080/14656566.2019.1574752
  44. Piccoli, R., Mandato, V.D., Lavitola, G., et al. “Atypical squamous cells and low squamous intraepithelial lesions in postmenopausal women: Implications for management.” Eur J Obstet Gynecol Reprod Biol 140 (2008): 269–74. DOI: 10.1016/j.ejogrb.2008.05.007
  45. Patton, A.L., Duncan, L., Bloom, L., et al. “Atypical squamous cells, cannot exclude a high-grade intraepithelial lesion and its clinical significance in postmenopausal, pregnant, postpartum, and contraceptive-use patients.” Cancer 114 (2008): 481–8. DOI: 10.1002/cncr.23949
  46. Flynn, K., Rimm, D.L. “Diagnosis of ”ASCUS” in women over age 50 is less likely to be associated with dysplasia.” Diagn Cytopathol 24 (2001): 132–6. DOI: 10.1002/1097-0339(200102)24:2<132::AID-DC1026>3.0.CO;2-N
  47. Misra, J.S., Srivastava, A.N., Zaidi, Z.H. “Cervical cytopathological changes associated with onset of menopause.” J Midlife Health 9 (2018): 185–90. DOI: 10.4103/jmh.JMH_4_18
  48. Eleuterio, J., Giraldo, P.C., et al. “Liquid-based cervical cytology and microbiological analyses in women using cooper intrauterine device and levonorgestrel-releasing intrauterine system.” Eur J Obstet Gynecol Reprod Biol 255 (2020): 20–4. DOI: 10.1016/j.ejogrb.2020.09.051
  49. Kim, Y.J., Youm, J., Kim, J.H., Jee, B.C. “Actinomyces-like organisms in cervical smears: the association with intrauterine device and pelvic inflammatory diseases.” Obstet Gynecol Sci 57 (2014): 393. DOI: 10.5468/ogs.2014.57.5.393
  50. Gajdács, M., Urbán, E. “The Pathogenic Role of Actinomyces spp. and Related Organisms in Genitourinary Infections: Discoveries in the New, Modern Diagnostic Era.” Antibiotics 9 (2020): 524. DOI: 10.3390/antibiotics9080524



How to Cite

Burka, O. ., Lygyrda, N. ., Kutsovol, V. ., & Svintsitska, A. . (2021). The cytological component of cervical cancer screening: causes of false negative and false positive results, and ways to avoid them. REPRODUCTIVE ENDOCRINOLOGY, (57), 61–67.



Tumors and pretumoral pathology

Most read articles by the same author(s)

1 2 > >>