From the Guidelines
For a 21-year-old with atypical squamous cells of undetermined significance (ASCUS) on Pap smear, the recommended approach is repeat cytology in 12 months, as outlined in the guidelines 1. No immediate colposcopy is needed for this age group with ASCUS findings. This recommendation differs from management in older patients because HPV infections and minor cervical abnormalities are very common in young women and typically resolve spontaneously without treatment. The natural history of HPV in this age group shows that over 90% of infections clear within 1-2 years. Aggressive evaluation of ASCUS in women under 25 can lead to unnecessary procedures and potential harm through overtreatment of transient lesions. During the follow-up period, the patient should continue routine healthcare, avoid smoking which can impair immune clearance of HPV, and consider HPV vaccination if not already completed. If the repeat Pap remains abnormal at 12 months, further evaluation with colposcopy would then be appropriate, as suggested by the guidelines 1. No specific medications are indicated for ASCUS management as this represents a cytologic finding rather than a disease requiring treatment. Key points to consider in management include:
- Repeat Pap testing at 12 and 24 months for women under 21 with ASCUS, as recommended 1
- Consideration of HPV vaccination if not already completed
- Avoidance of smoking to aid in immune clearance of HPV
- Routine healthcare follow-up to monitor for any changes or development of symptoms.
From the Research
Atypical Squamous Cells of Undetermined Significance (ASCUS) in Pap Smear Workup
- A 21-year-old patient with ASCUS in their Pap smear workup may require further evaluation to determine the presence of underlying cervical intraepithelial neoplasia (CIN) or other abnormalities.
- According to a study published in 2001 2, the sensitivity and specificity of repeat Pap smear alone for detecting CIN 2/3 were 73.7% and 62.9%, respectively.
- The same study found that human papillomavirus (HPV) DNA testing had a sensitivity of 68.4-89.5% and specificity of 59.0-85.9% for detecting CIN 2/3, depending on the testing method used.
- A 2003 study 3 found that reflex HPV DNA testing on liquid-based Pap smears with ASCUS interpretations identified 65.7% of women as positive for high-risk HPV types, and histologic follow-up revealed a significant risk of high-grade lesions.
- A more recent study published in 2019 4 analyzed the correlation between ASCUS cytology, high-risk HPV test, and histopathologic follow-ups in a large cohort of women in China, finding an overall ASC-US reporting rate of 3.77% and a CIN2+ detection rate of 7.87%.
Management and Follow-up
- The 2001 study 2 suggested that a promising strategy for managing ASCUS would be to refer women with repeat Pap smears showing squamous intraepithelial lesion and/or those positive for high-risk HPV detected by Hybrid Capture testing for colposcopy.
- The 2003 study 3 found that clinicians were basing colposcopy triage on the HPV test result rather than the definitiveness of the cytologic interpretation, suggesting that HPV testing can inform management decisions.
- The 2019 study 4 found that women with ASCUS Pap test findings and positive HPV test results had a significantly higher risk of CIN2+ lesions and cervical squamous cell carcinoma, highlighting the importance of follow-up and further evaluation in these cases.