Acta Dermato-Venereologica 99-3CompleteContent | Page 24

339 SHORT COMMUNICATION Association of Vulvar Melanoma with Lichen Sclerosus Niina HIETA 1 , Samu KURKI 2 , Marjut RINTALA 3 , Jenni SÖDERLUND 3 , Sakari HIETANEN 3 and Katri ORTE 4 Departments of 1 Dermatology, 3 Obstetrics and Gynaecology and 4 Pathology, Turku University Hospital and University of Turku, PO Box 52, FIN-20521 Turku, and 2 Auria Biobank, University of Turku and Turku University Hospital, Turku, Finland. E-mail: [email protected] Accepted Dec 6, 2018; E-published Dec 6, 2018 Lichen sclerosus (LS) is a chronic inflammatory skin disease presenting mainly on the anogenital area. The prevalence of LS has been estimated as 1:300 to 1:900, and even higher in elderly women (1, 2). The life-time risk of female patients with LS developing vulvar squamous cell carcinoma (SCC) is 4–5% (1). Vulvar melanoma is rare, with an incidence of 0.10–0.13 per 100,000 individuals, presenting typically in post-me- nopausal women (3, 4). In Finland, the incidence of vulvar melanoma between years 2010 and 2014 was 0.08–0.12 per 100,000 individuals (The Finnish Cancer Registry: data upon request), which is in line with other vulvar melanoma incidence studies. Reports on vulvar melanoma among patients with LS are few. So far, 4 cases have been descri- bed among adult patients and 6 cases in prepubertal girls (3, 5, 6). The aim of this study was to clarify the possible connection between LS and vulvar melanoma. METHODS A data search identifying female patients with reported SNOMED Clinical Terms for LS (M58240) and vulvar melanoma (M87203) between 1 January 2000 and 1 September 2013 was conducted in Auria Biobank, Turku University Hospital (TYKS). Clinical histories were obtained from medical records. Population-based data for comparison regarding the incidence of vulvar melanoma were retrieved from the Finnish Cancer Registry. The study was approved by Auria Biobank’s Scientific Steering Committee and the Institutional Review Board of Turku University Hospital. Formalin-fixed, paraffin-embedded specimens of primary vulvar melanomas and reoperations were obtained from Auria Biobank. Haematoxylin-eosin stained slides from the melanoma specimens were examined by a pathologist to confirm or exclude the diagnosis of LS, and to confirm the Clark stage and Breslow’s index (Fig. 1). Survival time was calculated from date of diagnosis to date of death or 1 September 2013, whichever came first. To calculate the relative risk of vulvar melanoma among patients with LS compared with those without LS, a 2-by-2 contingency table analysis was used. To compare Breslow and Clark staging, Student’s t-test for 2 independent means for Breslow and one-way analysis of variance (ANOVA) for Clark were used. One-way ANOVA was used to compare tumour stage and the Kaplan–Meier estimator to study survival. To compare the 2 survival curves, the log-rank test was used. A p-value lower than 0.05 was considered significant. RESULTS The data search found 249 patients with vulvar LS, confir- med by biopsy. Among these patients, 3 vulvar melanomas were identified (Table SI 1 ). As comparison, 30 cases of SCC were found among patients with LS. Representative macroscopic and histological images of the melanomas are shown in Fig. 1. The patients were not diagnosed with LS until the diagnosis of melanoma was made. Six mela- nomas were diagnosed among patients who did not have LS among a total population of 250,000 female subjects. The risk of vulvar melanoma among patients with LS was https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-3103 1 Fig. 1. (A) Vulvectomy specimen with in situ melanoma on the right lower part (arrow). The patient previously operated for an exophytic melanoma had a re-operation of the tumour area. Typical features of lichen sclerosus (LS) are seen, including a porcelain-white area above clitoral hood (arrowheads). (B) Late stage of LS with hyalinization of the dermis and deep inflammatory infiltrates. (C) Histological image of invasive vulvar melanoma with nodular growth. The tumour cells have abundant eosinophilic cytoplasm and marked nuclear atypia with enlarged nucleoli. Mitotic frequency was high and some granular pigment consistent with melanin was seen. (D) In situ melanoma with tumour cells spreading at the dermoepidermal junction (arrow) and in the epidermal layers (arrowhead). (E) Kaplan–Meier survival curves showing survival of vulvar melanoma patients with or without LS. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3103 Acta Derm Venereol 2019; 99: 339–340