Automated in Situ Hybridization for Human Papilloma Virus

With the increased number of requests for high-risk human papilloma virus in situ hybridization (HPV ISH), not only for uterine cervical squamous cell carcinoma (SCC) but also for biopsies and resections of oropharyngeal SCC, and fine needle aspiration cell blocks of metastatic SCC in cervical lymph nodes, we optimized an automated method to replace the manual one we had used. The new technique used the Leica BOND-maX or III immunostainer, already in use for immunohistochemical analysis, with the Enzo HPV type 16/18 and 6/11 probes. We stained 55 surgical biopsies and 41 cell blocks of oropharyngeal SCC. Sensitivity was 90% and 73% for biopsies and cell blocks, respectively, with a specificity of 100% in both. Stain is strong and crisp with no background. Turnaround time is short as runs are performed daily, with up to 30 slides per run. Technologists become trained in a few days, and the repeat rate is low. The only disadvantage is that ISH and IHC cannot be performed simultaneously. We highly recommend this automated technique for high-risk and low-risk HPV ISH and probably with other probes.