The biopsy specimen showed hyperplastic mucosal epithelium with acanthosis and anastomosing rete ridges.(Figure 2). There was slight pallor of the squamous epithelium and focal koilocytosis (Figure 3), but significant cellular atypia and mitoses were absent. There was no significant associated inflammation. The specimen was found to be positive for human papillomavirus (HPV) type 13 by polymerase chain reaction analysis.
Asymptomatic Labial Papules in a Teenager. Arch Dermatol. 2002;138(11):1509. doi:10.1001/archderm.138.11.1509