RESUMO
BACKGROUND: Epidermodysplasia verruciformis (EDV) is a rare cutaneous manifestation of human papilloma virus infection, which has a potential for malignant transformation. The characteristic histologic features of EDV may not always be present and may often be overlooked. The use of a panel of novel biomarkers may aid in differentiating EDV from their clinical and pathologic mimics. MATERIAL AND METHODS: We reviewed 20 cases histologically diagnosed as EDV from 2013 to 2022. Sections were reviewed for histopathologic features, and immunohistochemistry for p16 and Ki67 was performed. RESULTS: There were 20 cases, ranging in age from 6 to 52 years with a male predominance. Four patients were immunosuppressed, and 4 patients had a positive family history. The most common presentation was hypopigmented papules and macules. In all the cases, epidermal keratinocytes showed dysmaturation, enlargement, and a blue-gray cytoplasm. These changes were very focal and superficial in 15 cases (75%). Associated malignancies included carcinoma in situ (1), trichilemmoma (2), and trichilemmal carcinoma (1). The trichilemmal tumors were seen in 2 siblings. p16 was expressed in the parabasal and basal layers in 7 of 17 cases (41%), in keratinocytes with and without inclusions. Ki67 was increased and localized to suprabasal and parabasal keratinocytes in 15 of 17 cases (88%). CONCLUSION: Although striking and characteristic, the keratinocyte changes are often focal and superficial, requiring multiple step-sections. Association of EDV with familial trichilemmal neoplasms is a novel finding requiring further genetic testing. In cases of clinically suspected EDV with negative histopathologic findings, p16 and Ki67 seem useful as adjunct biomarkers and could serve as cost-effective alternatives to genotyping.