[A new type of viral wart? A case of viral wart having intracytoplasmic filamentous substances].

Reported was a 16-year old Japanese girl suffering from peculiar viral warts on the soles. All lesions showed whitish punctate keratotic appearance. Three biopsy specimens taken from one patient were found to have particular intracytoplasmic basophilic eosinophilic filamentous substances in each cell. These intracytoplasmic substances were quite different from those of myrmecia, which was described as inclusion wart by Lyell and Myles. Myrmecia is caused by human papillomavirus type 1 (HPV-1) and its intracytoplasmic substances are characterized by numerous intracytoplasmic eosinophilic granules. In spite of that immunohistologically papillomavirus common antigens were detected, HPV-1,2,4 was never detected by in situ hybridization method in our case. We assume that our case is a new type of viral wart.