Detection of papilloma virus of the human uterine cervix by in situ hybridization method--comparison with immunohistochemistry

The usual methods for pathological diagnosis of HPV infection of the uterine cervix include screening in cytodiagnosis and histodiagnosis and confirmation by immunohistochemistry (IHC) method. However, some institutes have recently begun to use in situ hybridization (ISH) method for definitive diagnosis using a DNA probe. We compared IHC with ISH with regards to the localization and rate of detection of HPV in lesions of the uterine cervix such as dysplasia and squamous cell carcinoma in the present study. The cases found positive by IHC showed brownish nuclei of the epithelium and those positive in ISH showed purple to purplish-black nuclei. The comparison of cases positive by both methods revealed that the number of cells positive by IHC was smaller than that by ISH, and the cells positive by IHC were localized in the superficial layer. HPV was detected by the IHC various lesions of the uterine cervix in 13 (12.3%) of 106 patients, while it was detected by the ISH in 39 (36.8%) of 106 patients. The results of both methods were in accordance in 66.0% (77 patients; positively in 8 and negatively in 62). The detection sensitivity of IHC is lower than that of ISH. IHC cannot be used to identify the type of HPV, and it is impossible to confirm the presence or absence of virus by this method in cases of malignant changes. ISH is therefore necessary for identification of HPV and investigation of a histopathological relationship between HPV type and malignant change.