Epidermodysplasia Verruciformis: A Study of Clinicopathologic Features, Biomarkers, and Associated Malignancies in...

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.

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.

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%).

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.