Correlation between human papillomavirus (HPV) type and histology of warts

Forty warts from different patients and of different clinical type were examined histologically and virologically. Eight lesions were found to be associated with human papillomavirus type 1 (HPV 1), 15 tumors were induced by HPV 2, HPV 3 was detected 4 times, HPV 4 twice, and HPV 6 eleven times. HPV 3, HPV 4, and HPV 6 induced warts revealed a correlation between histology and virus type. They are characterized by the so called "edematous type clear cells". In HPV 3 associated flat warts pycnotic nuclei were mainly localized in the center of large vacuoles. In genital warts sickle shaped nuclei were pushed to the margin of the vacuolized cells. The histology of HPV 1 and HPV 2 induced warts was more heterogenous. With one exception HPV 1-induced lesions represented typical myrmecia warts, varying in the number and shape of inclusion bodies. HPV 2 associated common warts, however, revealed 3 very distinct histologic features: (1) Inclusion wart typical for HPV 1, (2) Classical common wart with marked condensation of keratohyalin granules, (3) Warts with extreme vacuolization of squamous and granular cells leading to a honeycomb-like picture.