Can ASCUS Be Reported on Vault Smears After Total Hysterectomy?
Yes, ASCUS findings can technically be reported on vaginal vault smears after total hysterectomy, but routine vault cytology screening is generally not recommended for women who underwent hysterectomy for benign indications without a history of high-grade cervical intraepithelial neoplasia (CIN 2 or higher).
Screening Recommendations After Hysterectomy
The guidelines are clear about when vault cytology should and should not be performed:
Women who should discontinue screening 1, 2, 3:
- Total hysterectomy performed for benign indications
- No history of high-grade CIN (CIN 2 or 3)
- No history of cervical cancer or adenocarcinoma in situ
Women who require continued vault surveillance 2, 3, 2:
- History of CIN 2 or 3 prior to hysterectomy
- History of cervical cancer
- Should continue annual screening until three consecutive satisfactory negative vaginal cytology results are obtained
- After three consecutive negative results, screening can be discontinued
When ASCUS Can Appear on Vault Smears
While vault cytology is not routinely recommended for most post-hysterectomy patients, when it is performed (either appropriately in high-risk patients or inappropriately in routine screening), ASCUS findings can occur 4:
Clinical significance of vault cytology findings:
- A 2022 study of 155 women with early cervical cancer treated with hysterectomy found that of 1001 vault smears performed, 1.9% were abnormal 4
- Low-grade abnormalities (1.6% of smears) all resolved with observation alone 4
- Importantly, vault cytology did not alter detection of recurrent malignancy - all recurrences had visible lesions or abnormal imaging 4
Key Clinical Pitfalls
Common mistakes to avoid:
- Do not perform routine vault cytology on women who had hysterectomy for benign reasons without high-grade CIN history - this leads to unnecessary abnormal results that have minimal clinical significance
- If ASCUS is found on a vault smear in a woman with prior CIN 2/3, manage according to standard ASCCP guidelines with colposcopy or repeat cytology 1
- Remember that the Bethesda System terminology (including ASCUS) applies to any squamous epithelium, including vaginal vault epithelium 5
Management Algorithm
If ASCUS is reported on a vault smear:
Review surgical history:
- Was hysterectomy for benign or malignant indication?
- Was there prior high-grade CIN?
For women with prior CIN 2/3 or cervical cancer:
- Continue surveillance per guidelines
- Consider colposcopy of vaginal vault
- HPV testing may be useful for triage 2
For women with benign hysterectomy indication:
- Question why vault cytology was performed
- Low-grade abnormalities typically resolve spontaneously 4
- Clinical examination is more important than cytology for detecting vault abnormalities
The bottom line: While ASCUS can technically be reported on vault smears using standard Bethesda terminology, the more important question is whether vault cytology should have been performed at all, as guidelines recommend against routine screening in most post-hysterectomy patients 1, 3.