Relationship between Human Papilloma Virus and Subungual Keratoacanthoma: Two Case Reports and the Outcomes of Surgical Treatment.

Subungual keratoacanthoma (SUKA) is a rare form of keratoacanthoma, with the majority of the lesions appearing as rapidly growing, painful hyperkeratotic masses located under the distal nail plate of the thumb. In some cases, SUKA causes damage to the underlying bone. The first case presented here was treated by surgical excision alone, and human papilloma virus (HPV) type 6 was detected in the tissue samples. The second case was treated by surgical excision plus curettage; however, HPV was not detected, and tumor cells were not found in the curettage material. There was near complete improvement in both the clinical appearance and the distal phalanx destruction, with no recurrence at the final follow-up in either patient (30 and 14 months, respectively). Overall, simple excision alone or in combination with curettage seemed to be sufficient in the treatment of SUKA; however, the etiopathogenetic role of HPV in SUKA remains controversial, as in its classical form.