RNA chromogenic in situ hybridization assay with clinical automated platform is a sensitive method in detecting high-risk human papillomavirus in squamous cell carcinoma.

Detection of active human papillomavirus (HPV) is clinically important because its presence has been shown to correlate with favorable clinical outcomes and better response to treatment in oropharyngeal squamous cell carcinomas. Using a clinical automated platform, we compared the performance of commercially available HPV DNA and RNA in situ hybridization (ISH) probes in archival tissues of 57 squamous cell carcinomas. Importantly, a clinical automated platform gives (1) consistent and reproducible results for HPV ISH and (2) better standardization across clinical laboratories. Compared with polymerase chain reaction results, RNA ISH exhibited 93% concordance versus 81% of DNA ISH. RNA ISH was more sensitive than DNA ISH (100% versus 88%) and more specific (87% versus 74%). When only accounting for 2+-3+ positivity, sensitivity was 92% for RNA ISH versus 73% for DNA ISH, highlighting the ease of interpretation. p16 exhibited 96% sensitivity, whereas specificity was only 55%. In 3 cases, both RNA and DNA ISH were positive, whereas polymerase chain reaction results were negative, suggesting that ISH methods might be a more sensitive method. Performing on a clinical automated platform, RNA ISH is sensitive in determining high-risk HPV status in formalin-fixed, paraffin-embedded tissues and has the potential of being a standalone clinical test.

Clear Cell Carcinoma of the Penis: An HPV-related Variant of Squamous Cell Carcinoma: A Report of 3 Cases.

Penile clear cell carcinoma originating in skin adnexal glands has been previously reported. Here, we present 3 morphologically distinctive penile tumors with prominent clear cell features originating not in the penile skin but in the mucosal tissues of the glans surface squamous epithelium. Clinical and pathologic features were evaluated. Immunohistochemical stains were GATA3 and p16. Human papilloma virus (HPV) detection by in situ hybridization was performed in 3 cases, and whole-tissue section-polymerase chain reaction was performed in 1 case. Patients' ages were 52, 88, and 95 years. Tumors were large and involved the glans and coronal sulcus in all cases. Microscopically, nonkeratinizing clear cells predominated. Growth was in solid nests with comedo-like or geographic necrosis. Focal areas of invasive warty or basaloid carcinomas showing in addition warty or basaloid penile intraepithelial neoplasia were present in 2 cases. There was invasion of corpora cavernosa, lymphatic vessels, veins, and perineural spaces in all cases. p16 was positive, and GATA3 stain was negative in the 3 cases. HPV was detected in 3 cases by in situ hybridization and in 1 case by polymerase chain reaction. Differential diagnoses included other HPV-related penile carcinomas, skin adnexal tumors, and metastatic renal cell carcinoma. Features that support primary penile carcinoma were tumor location, concomitant warty and/or basaloid penile intraepithelial neoplasia, and HPV positivity. Clinical groin metastases were present in all cases, pathologically confirmed in 1. Two patients died from tumor dissemination at 9 and 12 months after penectomy. Clear cell carcinoma, another morphologic variant related to HPV, originates in the penile mucosal surface and is probably related to warty carcinomas.