A comparison of proliferative activity and atypical mitoses in cervical condylomas with various HPV types.

Cervical condylomas associated with HPV types 6/11 rarely progress to dysplasia; this progression is more commonly seen in cervical condylomas with HPV types 16/18/31/33/35. This investigation was undertaken to determine if more frequent atypical mitotic figures (MFs) and higher proliferative activity are seen in high-risk condylomas. HPV types present in cervical condylomas were determined by in situ hybridization with biotinylated probes. The cases were also stained immunohistochemically for MIB1. The percentage staining of basal, parabasal, and suprabasal cells was determined by counting 100 cells in the most intensely stained areas. MFs and atypical MFs were counted per 10 high-power-fields (HPFs). Condylomas with HPV 6/11 showed higher MIB1 expression in the basal layer than condylomas with HPV 16/18 and 31/33/35 (p = 0.013). Atypical MFs were seen more frequently in condylomas with HPV types 16/18/31/33/35 (p = 0.02). Differences in mitotic activity and in MIB1 expression in parabasal and suprabasal layers did not reach statistical significance. The presence of atypical MFs may make a greater contribution than increased proliferative activity to progression to dysplasia in cervical condylomas.