Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (261 page)

   For women who have undergone total hysterectomy and who have not had a history of CIN 2, CIN 3, or adenocarcinoma in situ in the previous 20 years, no screening is necessary.

   For women vaccinated against HPV, follow age-specific recommendations similar to unvaccinated women.

Follow-up of screening tests as follows:

   Negative cytology and negative HPV rescreen in 5 years

   ASCUS Pap and negative HPV rescreen in 3 years

   Negative cytology and positive HPV repeat cotesting in 12 months or test for HPV 16/18

   If HPV 16/18 positive refer to colposcopy

   If HPV 16/18 negative repeat cotesting in 12 months

Referral of patients for colposcopic examination and biopsy should be performed for patients with positive HPV 16 or 18 and any cytology results higher than LSIL or any patient with atypical glandular cells. Patients should undergo biopsy of any visualized cervical lesions and endocervical curettage if no lesions are apparent (see eBook Figures 8-6 and 8-7). For patients with abnormal Pap tests (ASCUS and HSIL), positive high-risk HPV DNA test and negative biopsy additional tissue diagnosis should be attempted with conization (loop electrocautery excision).

For women diagnosed with invasive squamous cell carcinoma of the cervix, imaging studies (CT or MRI) are recommended to evaluate possible involvement of adjacent organs or metastases.

Testing options:

Many laboratories now offer reflex testing for HPV from the liquid pap vial based on the ACOG recommendations, making it easier for the clinician. In addition, PCR testing for GC,
Chlamydia
, and
Trichomonas
may also be performed on the same liquid pap vial.

Limitations of the Pap test:

   False-negative results in approximately 5–10% of cases.

   Unsatisfactory cellularity occurs with fewer than 5,000 well-visualized, wellpreserved squamous cells in a liquid-based Pap, and 8,000 cells on a conventional smear are obtained.

   Sampling problems occur in up to 10% of samples collected; these have integrity issues and are considered unsatisfactory due to the presence of blood or mucous, inflammation, insufficient cells, or problems with the slide preparation. Malignant cells may not be present if the smear is repeated too soon after a previous abnormal smear.

   The Pap test was designed to screen for squamous tumors. Other tumor types are less readily diagnosed (e.g., adenocarcinoma, lymphoma, and sarcoma).

   Human error in interpreting difficult cells; <3% of preventable cervical cancers are due to misread smears.