Keratoacanthomas: Human Papillomavirus Associated?

Abstract
To the Editor.— Despite several reports on the recovery of human papillomaviruses (HPVs) from keratoacanthomas (KAs), it is still unclear if HPVs are, in fact, involved in the genesis of this tumor. Even the type(s) of HPV implicated is a matter of controversy: Scheurlen et al1 cloned HPV type 37, which is related to HPV types 19 and 25, from a single KA; Pfister et al2 obtained evidence suggesting the presence of DNA from HPV types 19 and 25 in two of six KAs by reverse Southern blot hybridization. In a subsequent follow-up survey, Gassenmaier et al3 reported recovery of HPV type 25—related DNA in 14 of 32 solitary KAs by in situ hybridization with biotinylated probes. Remarkably, only a few single cells were positive. Trowell et al4 demonstrated HPV type 25—related DNA, possibly representing a novel HPV type, in one of 13 KAs investigated by