Classification of vulvar precancerous lesions: the pathologist´s view (article in Czech)
P. Škapa, T. Pichlík, M. Pluta, M. Halaška, H. Robová, L. Rob, R. Tachezy, J. Zámečník
Actual Gyn 2014, 6, 26-32
Publication date: 2014-03-18
Manuscript ID: 0614010
Number of views: 2664

Classification of vulvar precancerous lesions is based on the concept of vulvar intraepithelial neoplasia (VIN). Two basic types of VIN are recognized histologically: VIN of the usual type (u-VIN) and VIN of the differentiated type (d-VIN). The three grade evaluation system is used to assess the intesity of dysplastic changes in u-VIN (u-VIN I, II and III). The precancerous potential of d-VIN corresponds to carcinoma in situ and therefore grading is not applied. u-VIN is etiologically linked to HPV infection, whereas d-VIN is HPV negative and emerges in the environment of chronic vulvar dermatoses (lichen sclerosus and lichen simplex chronicus). u-VIN has a tendency to multifocality and prolonged recurrent progression to the invasive squamous cell carcinoma. On the other hand, d-VIN represents rather a solitary lesion with a propensity to the rapid stromal invasion. u-VIN usually affects premenopausal women with a higher incidence of other precancerous lesions of the lower female genital tract including the perineum and anal area. Patients diagnosed with d-VIN are of postmenopausal age without any association with aforementioned dysplastic lesions of other anatomic locations. The low diagnostic reproducibility of the u-VIN I category, doubts about the precancerous potential of u-VIN I and the problematic distinction between u-VIN II and u-VIN III resulted in the modification of the current terminology. The grading of u-VIN was abandoned, u-VIN II and u-VIN III categories were merged and u-VIN I was removed from the classification scheme. The revised u-VIN category therefore represents high grade dysplastic lesions associated with HPV infection (former u-VIN II and u-VIN III categories) and the term d-VIN is still reserved for the HPV negative high grade vulvar precancerosis.

Key words: vulvar intraepithelial neoplasia, VIN of the usual type, VIN of the differentiated type, lichen sclerosus, lichen simplex chronicus, HPV