Verruciform xanthoma associated with squamous cell carcinoma.

Verruciform xanthoma (VX) is a rare lesion of unknown etiology that is typically solitary and predominantly located within the oral cavity. Less commonly, they arise on the skin, with the majority of cases occurring in anogenital sites. They can be confused clinically with verruca vulgaris, condyloma, leukoplakia, verrucous carcinoma, and squamous cell carcinoma. Histologic features include acanthosis with uniform elongation of the rete ridges and xanthomatous cells that lie in and are typically confined to the papillary dermis. Although epidermal atypia is not a characteristic finding, we describe an unusual case of VX that has features of both VX and squamous cell carcinoma. In addition, there was a VX with typical histologic characteristics located at a separate site in the same patient. This case is also the first to our knowledge to be reported on the neck and axilla and is the third case associated with cutaneous graft versus host disease secondary to bone marrow transplant for acute lymphoblastic leukemia.