1, acetic acid white test with 3-5% acetic acid topical application of warts for 2-5 minutes, the lesions become white slightly elevated, anal lesions may take 15 minutes. The principle of this test is the result of protein and acid coagulation whitening, HPV infected cells produce keratin and normal uninfected epithelial cells produce different, only the former can be decolorized by acetic acid. The sensitivity of the white acetate test for detecting HPV is high, and it is better than the conventional test for observing histological changes. However, occasionally false-positive, false-positive signs of whitening appear ill-defined and irregular in cases of epithelial thickening or traumatic abrasions. The CDC suggests that the white acetate test is not a specific test, and false positives are more common. If there is viral antigen in the lesion, the antigen-antibody combination. In the peroxidase-anti-peroxidase (PAP) method, the nucleus can be stained red. This method is specific and more rapid, which is helpful for diagnosis. 4, pathological examination is mainly incomplete keratinization, spiny layer highly hypertrophic, papilloma-like hyperplasia, epidermal protrusions thickened and prolonged, the degree of hyperplasia can resemble pseudoepithelioma-like. The spiny cells and basal cells had a considerable number of nuclear divisions and resembled carcinoma. However, the cells were regularly arranged and the boundary between the proliferating epithelium and dermis was clear. It is characterized by the formation of vacuoles in the granular layer and the upper cells of the spiny layer. These vacuolated cells are larger than normal, with light cytoplasmic coloration and large, round, deeply basophilic nuclei in the center. Bushke-loewenstein giant condyloma acuminatum has extreme downward epidermal growth that replaces the underlying tissue and is easily mixed with squamous cells, so multiple biopsies are required. If there is a tendency for slow progression, this is a low-grade malignant process known as verrucous carcinoma.