
Home
Chapter Home
Jobs
Conferences
Fellowships
Books
Advertisement
Cervix-Cytology
Atypia / premalignant / preinvasive lesions
Atypical squamous cells of undetermined significance (ASC)
Reviewer: Marilin Rosa, M.D., University of Florida (see Reviewers page)
Revised: 7 June 2011, last major update June 2011
Copyright: (c) 2006-2011, PathologyOutlines.com, Inc.
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 2.5-3x size of intermediate cell nucleus or 1.5x size of mature metaplastic cell nucleus
● In perimenopausal women (40-55 years), cells with bland nuclear enlargement (2-3x 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
=========================================================================

Various images

Cytologic changes NOT typical of ASC-US
![]()
Mild nuclear enlargement
![]()
Nuclear enlargement with atrophy
![]()
Nuclear enlargement with hyperchromasia and irregular nuclear membranes

ASC-US possibly LSIL

ASC-H or HSIL

ASC-H
![]()
ASC-US
Additional references
=========================================================================
End of Cervix-cytology > Atypia / premalignant / preinvasive lesions > Atypical squamous cells of undetermined significance (ASC)
This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.
All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).