Introduction/Background The main problem connected with lichen sclerosus is inflammatory proccess and correlation of this vulvar dermatose with autoimmunological and neoplastic diseases. Photodynamic therapy is one of the most popular worldwide discussed method of treatment of lichen sclerosus. Despite the short history, this method has a quiet good benefits.

The aim of the study was to assess the influence of neoplastic disease on effectiveness of photodynamic therapy used in lichen sclerosus treatment.

Methodology Analysis was based on 182 patients with age 31–88 from Outpatient Vulvar Clinic, which is a part of Department of Obstetrics, Gynecology and Gynecological Oncology. Material was divided into 3 groups: patients with neoplastic disease in history, women with positive familiar history of neoplastic disease and women neither medical history nor familiar history of neoplastic diseases.

Analysis was based on immunohistochemical reaction in samples of vulvar biopsy with receptors TLR, mast cells, Langerhans cells and MeCP2 - Methyl-CpG-binding protein 2, vulvoscopic assessment with special scales our own authorship before and 10 weeks after photodynamic therapy and questionnaire of patients’ vulvar symptoms before and after the treatment.

Results TLR3, TLR9 and Langerhans cells take part in advanced stage of lichen sclerosus pathogenesis. MeCP2 occurs in every stage of lichen sclerosus. Localization depends on different stage of disease and can be in every layer of the skin. The role of this protein is to take part in epigenetics process.

In vulvoscopic assessment, the percentage of improvement after PDT was higher in group of women with no correlation to neoplastic diseases (55,3%) than in women with contact with neoplastic disease (47,7%).

According to subjective symptoms connected with lichen sclerosus the most frequent was itching, which stand for 76,2%; 71,7% and 66,9% in following groups. In comparison to other complains, the highest percentage of every group were patient with neoplastic disease in the past. Satisfaction with the level above 50% after photodynamic therapy reffered 80,8% patients from all analysed population.

Conclusion To sum up, the presence of neoplastic disease can influence on tissue and clinical phenotype on effectiveness of photodynamic therapy used in treatment of lichen sclerosus.