Squamous Precursor Lesions of the Vulva: A Practical Approach.

Vulvar squamous cell carcinoma and its precursors are heterogeneous and classified into 3 biologically distinct subgroups: human papillomavirus (HPV)-associated, HPV-independent TP53-mutated, and HPV-independent TP53-wild type. Although nomenclature is established for HPV-associated high-grade squamous intraepithelial lesion and TP53-mutated differentiated vulvar intraepithelial neoplasia lesions, terminology for precursors in the TP53-wild-type subgroup is evolving. Accurate classification is essential, as prognosis, progression risk, and recurrence rates differ among subgroups. Diagnosis relies on integrated assessment of clinical presentation, histopathology, and immunophenotype, particularly p16 and p53 expression.