Cervix
Premalignant / preinvasive lesions - cytology
ASCUS (cyto)
Author: Marilin Rosa, M.D.
Topic Completed: 5 June 2006
Minor changes: 16 November 2020
Copyright: 2006-2021, PathologyOutlines.com, Inc.
PubMed search: Cervix Atypical squamous cells of undetermined significance (ASC)
Table of Contents
Definition / general | Terminology | Clinical features | Treatment | Cytology description | Cytology images | Additional referencesCite this page: Rosa M. ASCUS (cyto). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cervixcytologyatypicalsquamouscells.html. Accessed January 18th, 2021.
Definition / general
- May be neoplastic (HPV related, LSIL, HSIL) or reactive
Terminology
- Formerly called ASCUS
- ASC is subdivided into atypical squamous cells of undetermined significance (ASC-US) and atypical squamous cells, cannot rule out a high grade lesion (ASC-H)
Clinical features
- In cervical smears, often related to SIL, now or at later biopsy (Mod Pathol 1994;7:920)
- Poor reproducibility for this diagnosis
- Typical ASC-US / SIL diagnostic ratio for a laboratory is 3:1; often lower for liquid based cytology
- HPV testing is recommended after ASC-US diagnosis (Gynecol Oncol 2005;99:S7, J Natl Cancer Inst 2002;94:102, Am J Clin Pathol 2011;135:468); may also be helpful for ASC-H diagnosis (Cancer 2005;108:32), particularly if result is negative (Cancer 2005;105:457)
- For liquid based cytology diagnoses of ASC-US, reprocessing of residual material often causes reclassification to LSIL or HSIL (Diagn Cytopathol 2005;33:434)
- Higher risk for SIL in HIV+ women (Clin Infect Dis 2006;42:855)
Treatment
- Repeat cytology, colposcopy, or perform DNA testing for high risk HPV subtypes according to age group or previous history of dysplasia
Cytology description
- Nuclear changes are more marked than reactive, less than LSIL
- Nucleus is 2.5 - 3× size of intermediate cell nucleus or 1.5× size of mature metaplastic cell nucleus
- In perimenopausal women (40 - 55 years), cells with bland nuclear enlargement (2 - 3× size of intermediate cell nuclei), smooth nuclear membranes and fine chromatin are likely to be negative for SIL / malignancy (Am J Clin Pathol 2005;124:58)
Cytology images
Contributed by Marilin Rosa, M.D.
Degenerative atypical cells
Images hosted on other servers:
Various images
Untypical Cytologic changes
ASC-H
Additional references
