Abstract
Similarly to testicular tumors, key changes on penile and scrotal neoplasia were incorporated into WHO classification 2016. Therein, penile squamous cell carcinomas were divided into two groups based on the pathogenesis, namely HPV-associated and HPV-independent.
This remains unchanged in WHO classification 2022. For those carcinomas where HPV status can not be determined, a category of squamous cell carcinoma NOS was added.
Variants of squamous cell carcinoma, namely basaloid, papillary-basaloid, warty, warty-basaloid, clear cell and lymphoepithelioma-like carcinomas are not recognized as distinctive variants of HPV-associated group anymore. Similarly, squamous cell carcinoma, usual type, pseudohyperplastic, pseudoglandular, verrucous carcinoma, carcinoma cunniculatum, papillary, adenosquamous, sarcomatoid and mixed carcinoma are no more not recognized as distinctive variants of HPV-independent carcinomas.
Instead, these variants are now called subtypes. Some previously distinct subtypes now belong to the morphological spectrum of other subtypes.
Basaloid-papillary subtype belongs to basaloid squamous cell carcinoma and carcinoma cunniculatum is currently recognized as morphological variation of verrucous carcinoma. Pseudohyperplastic and mixed subtypes were removed from the classification.
Adenosquamous carcinoma is currently termed adenosquamous and mucoepidermoid carcinoma and represents distinct entity. Precursor lesions of squamous cell carcinoma underwent substantial modifications in the WHO classification 2016 as well, and remain unchanged in WHO classification 2022.
Terminology for HPV - induced lesions have been unified to low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL). This classification applies to the whole anogenital area, including penis, anus, perianal region, vulva, vagina and uterine cervix.
LSIL is further divided to condyloma accuminatum and (penile) intraepithelial neoplasia grade 1 (PeIN1), HSIL is divided to PeIN2 and PeIN3. Penile HPV-independent precursor lesions are named differrentiated penile intraepitelial neoplasia (dPeIN) and are identical to analogous lesions on vulva.