Premalignant / preinvasive lesions - cytology

ASCUS (cyto)

Topic Completed: 5 June 2006

Minor changes: 31 August 2021

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PubMed search: Cervix Atypical squamous cells of undetermined significance (ASC)

Marilin Rosa, M.D.
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Cite this page: Rosa M. ASCUS (cyto). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cervixcytologyatypicalsquamouscells.html. Accessed December 3rd, 2021.
Definition / general
  • May be neoplastic (HPV related, LSIL, HSIL) or reactive
  • 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
  • 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

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Various images

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Untypical Cytologic changes

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Additional references
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