Abstract

HPV independent vulvar intraepithelial neoplasia(VIN) is a newly defined entity recently recognized by the WHO. It is broadly divided into two types based on TP53 expression: differentiated type(dVIN) associated with chronic inflammation and abnormal TP53 and those with wild-type TP53 expression.  The latter type is further classified into two subtypes namely, differentiated exophytic vulvar intraepithelial lesion(DEVIL) and vulvar acanthosis with altered differentiation(VAAD). Furthermore, a broader term “vulvar aberrant maturation” has been proposed to incorporate both DEVIL and VAAD. We present a case of a 67-year-old female with a recurrent HPV negative verrucous vulvar lesion, with xanthomatous features mimicking verruciform xanthoma. The initial excision of 2013 showed an endophytic lesion with hyperparakeratosis, acanthosis, loss of granular cell layer, no atypia, no lymphoplasmacytic or neutrophilic inflammation and papillary dermis with xanthomatous cells positive for CD68. The lesion has since recurred twice. The latest excision demonstrated multi-layered parakeratosis, loss of granular cell layer, distinctly pale, bland squamous cell proliferation throughout the lesion.  There was no cellular atypia, xanthomatous cells or neutrophilic inflammation identified. Moreover, TP53 and P16 staining showed wild-type expression and no evidence of xanthomatous cells by CD68. These are characteristic features of VAAD/DEVIL, considered precursor lesions for verrucous and squamous cell carcinoma. The lesion from 2013, that was diagnosed as “verrucous proliferation with xanthomatous features” lacked the verruciform xanthoma defining feature of neutrophilic inflammation/abscess formation, but had all the features befitting of VAAD/ DEVIL. This case highlights that VAAD/DEVIL can present with xanthomatous differentiation and can lead to misdiagnosis of verruciform xanthoma, a benign entity.