[Morphologic manifestations of human papillomavirus infection in the vulvar and anogenital region].

INTRODUCTION Human papillomavirus (HPV) infection of the female genital tract is a sexually transmissible disease most frequently manifested by warts on the vulva, anogenital region, vagina and cervix. Precancerous lesions of vulvar intraepithelial neoplasia (VIN) as well as the development of invasive malignant neoplasms are also related to the infections caused by some HPV types. Infections with HPV-6 and HPV-11, the disease is often polycentric, sometimes reaching gigantic dimensions, elicit venereal warts. Amongst several histological criteria for diagnosing this change, the most typical is koilocytosis, with perinuclear halo formation with a thick cytoplasmic border. Precancerous changes of the vulva and anogenital region are displastic changes of the squamous epithelium, characterized by high mitotic activity, disturbance of nucleocytoplasmic relationship and lack of differentiation in the upper epithelial layers. The changes in the epithelium divided into thirds starting from basal membrane is the main criterion in estimating the degree of dysplasia, marked by VIN 1, VIN 2 and VIN 3. According to the nuclear and cytoplasmic characteristics. VINs are subclassified into three types: basaloid, verrucous (condylomatous) and well differentiated. Basaloid and verrucous (condylomatous) VIN types are morphological markers of HPV infection. The squamous cell carcinoma of the vulva and anogenital region is a morphologically heteregenous neoplasm with particular histological entities connected with HPV infection. CASE REPORTS Four cases of patients with changes in the anogenital region in the form of small to gigantic polypoid formations were reported. The histological features corresponded to vulvar intraepithelial neoplasms (VIN lesions), as well as to neoplastic changes characteristic of HPV infection. The evolution of the changes from typical condylomas through VIN lesions to infiltrative neoplasms, taking place over the years, was also verified. DISCUSSION Some histologically typical epithelial changes in the scope of VIN, as well as some histological types of malignant neoplasms, are associated with HPV-16 and HPV-18, and with HPV-31 to a smaller extent. The oncogenic potential of these viruses is established by in vitro cultures, but also by their finding in 50-90% of genital neoplasia in different series analyzed. The oncogenic potential of the virus depends on numerous heteregenous and complex factors denoted as risk factors. A typical, morphologically well-differentiated change is condyloma acuminatum, with the finding of acanthosis, hyperkeratosis, parakeratosis, dyskeratosis, and koilocytosis, which is always an accompanying morphological quality in these changes. In precancerous lesions and infiltrative neoplasms, koilocytosis is not a necessary finding. CONCLUSION The HPV infection of the vulva and anogenital region is reflected in a spectrum of histological changes. Condylomatous verrucous lesions, smaller papular or plaque-like changes with VIN histological features, as well as infiltrative malignant neoplasia with certain histological properties, could be induced by different HPV types. In the absence of data of in situ hybridization and immuno-electron microscopy as the reliable evidence of the presence of a certain HPV genotype, histological changes mostly characteristic of HPV infection could serve as an indirect pathway.