Enhancing the scope of conventional cervical cytology for detecting HPV infection

Cervical neoplasia is attributed to a persistent Human Papilloma Virus infection. The Pap smear being the mainstay of cervical cancer screening in low-resource settings, we studied the nonclassical features which might indicate HPV infection. These included abortive koilocytes, mild dyskeratosis, parakeratosis, mild nuclear hyperchromasia, bi/multinucleation, measles cells, and keratohyaline-like granules. Two hundred and eight women with a satisfactory Pap smear and a Hybrid Capture II test were compared against the "HPV Gold Standard" for validation of the nonclassical signs. This was defined as one with any/all of the following: definite HPV-related lesions on Pap smear (LSIL and above), hrHPV positivity, and CIN I, or above on histology. The highest PPV and NPV were achieved by bi/multinucleation and mild nuclear hyperchromasia, respectively. The mean number of nonclassical signs for HPV Gold Standard-positive and -negative groups was 5.52 and 3.12 per smear, respectively (P < 0.0005). Abortive koilocytes, mild dyskeratosis, mild nuclear hyperchromasia, bi/multinucleation, parakeratosis, and diffuse keratohyaline granules had the best correlation with the gold standard (P < 0.05). Addition of nonclassical signs to established intraepithelial lesions on Pap smear increased the sensitivity from 52.31 to 59.10% and reduced the specificity from 100 to 98%. To maximize the benefit from grouping of these signs, various combinations were studied. The best was: abortive koilocytes, mild nuclear hyperchromasia, and bi/multinucleation. Another was abortive koilocytes, mild nuclear hyperchromasia, bi/multinucleation, and mild dyskeratosis. In conclusion, these signs proved useful for identifying HPV infection. Population-based studies are required to corroborate our findings.