OBJECTIVE: To determine the effectiveness of using glacial acetic acid (GAA) to convert unsatisfactory bloody ThinPrep (TP) cervical smear test to satisfactory, and identify associated missed diagnoses and high-risk HPV (hrHPV) genotypes. METHODS: In a retrospective descriptive cross-sectional analysis, all TP tests performed in Mississippi, USA, 2012-2016, were evaluated for unsatisfactory results owing to blood. Tests that were converted to satisfactory by GAA treatment, and corresponding anomalies and HPV genotypes were identified. RESULTS: Among 106 384 TP tests, there were 1460 (1.37%) unsatisfactory results, of which 1442 (98.77%) were converted to satisfactory after GAA treatment. Laboratory preprocessing with GAA increased costs minimally. Precancerous lesions were detected in 166 (11.51%) of 1442 GAA-treated samples, of which 12 (7.2%) were high-grade lesions, 110 (66.3%) were atypical squamous cells of undetermined significance, and 63 (57.3%) tested positive for hrHPV. Of 60 genotyped samples, 39 (65%) had non-HPV16 and non-HPV18. Including mixed infections, 48 (80%) contained less-common hrHPV types, reflecting an unexpected distribution in bloody specimens. CONCLUSIONS: GAA pretreatment of bloody TP tests would reduce the incidence of unsatisfactory results and missed high-grade lesions, and prevent the cost of repeat tests and delayed treatment. Clinicians without access to GAA should consider HPV testing.
