Pap Testing as Primary Screening
Managing Unsatisfactory Pap Test Results
An "unsatisfactory" pap test result (unsat) can be caused by a number of factors, including poor sample collection, obscuring inflammation or blood, use of lubricants, or interpretive errors.1 Although this unsatisfactory category constitutes 1% to 2% of all pap tests, patients with unsats are more likely to have histories of abnormalities and are at increased risk of harboring precancer or invasive cervical cancer; therefore it is important to monitor them closely.1-2
Causes and prevention of unsats
According to the Bethesda 2001 Guidelines, adequate squamous cellularity for conventional smears is defined as having an estimated minimum of 8,000 to 12,000 well-preserved and well-visualized squamous epithelial cells. For liquid-based pap tests, the number is 5,000. This estimation is determined by comparison with computer-generated reference images, rather than by counting.
Poor sample collection is the most common source of unsats. Several steps can be taken to help prevent unsatisfactory test results, including the use of proper collection devices and techniques. Additionally, sampling should not be done during active infection or bleeding.
Clinical relevance of unsats
A large, prospective study found that an unsatisfactory pap test result indicated a 1.6 to 4.0 times increased risk of harboring CIN 2/3 or invasive cervical cancer, compared with women with a normal pap test result.2 Because patients with unsats are more likely to have a history of abnormalities, it is important to monitor them closely.1 A repeat pap test has been shown to be an adequate follow-up of an unsat.2
ASCCP guidelines for unsats
According to the American Society for Colposcopy and Cervical Pathology (ASCCP) guidelines for the management of patients with "unsatisfactory for evaluation" pap test results, patients should have repeated testing within 2 to 4 months.3 The guidelines recommend repeat testing in 12 months for patients with other limiting factors such as blood or obscuring inflammation and lack of an endocervical component.3
1. Ransdell JS. Cancer Cytopathology. 1997;81(3):139-43.
2. Nygard JF, Sauer T, Nygard M, Skare GB, et al. CIN 2/3 and cervical cancer in an organised screening programme after an unsatisfactory or a normal Pap smear: A seven-year prospective study of the Norwegian population-based screening programme. J Med Screen. 2004;11:70-6.
3. Davey D, et al. ASCCP patient management guidelines: pap test specimen adequacy and quality indicators. American Society for Colposcopy and Cervical Pathology Journal of Lower Genital Tract Disease. 2002;6(3):195-9.