RESUMO
Background: Early inflammatory lesions of lichen sclerosus are histopathologically difficult to diagnose until the hallmark of the disease i.e., papillary sclerosis becomes visible in histological sections. Pre-sclerotic and late or resolved phases of the disease have not been extensively studied. Methods: We retrospectively reviewed all cases diagnosed as genital lichen sclerosus over a ten-year period from 2006 to 2016, correlating the clinical findings with the histological features. Results: A total of 133 cases of genital lichen sclerosus (90 males and 43 females) were identified. Both genders demonstrated a similar histological spectrum. Fifty eight (44%) cases were identified as having pre-sclerotic lichen sclerosus, 64 (48%) as having progressive disease and 11 (8%) cases were classified as fully resolved with atrophy. Asymptomatic vitiligoid lesions were identified in 19 (14%) cases of which 12 were male. Low-grade squamous cell carcinoma was seen within the areas affected by long-standing lichen sclerosus, in four patients (3%, 2 male). Limitations: We studied only haematoxylin and eosin stained sections. The presence of basement membrane thickening could have been better illustrated with the periodic acid–Schiff stain. Conclusion: The pathogenesis of lichen sclerosus probably involves an immune reaction to the basement membrane at the epidermal interface and around the adnexa. The initial band of inflammation shifts gradually downwards from the epidermal interface into the dermis destroying the vascular channels and appendages, resulting in excessive deposition of altered extracellular matrix. Basilar infiltration of lymphocytes along with a grossly vacuolated or thickened basement membrane is proposed as the characteristic diagnostic feature of the pre-sclerotic stage. Greater awareness of the clinicopathological spectrum of lichen sclerosus should enable early diagnosis and treatment, thereby preventing structural damage and possible malignant transformation in chronic cases
RESUMO
BACKGROUND: Many case studies of lichen sclerosus (LS) have reported an association of vitiligo. However, such an association is not reported from larger case studies of vitiligo, which happens to be a common disease. Autoimmune etiology suspected in both LS and vitiligo has been considered as the reason for their association in some patients. It has also been suggested that lichenoid inflammation in LS may trigger an autoimmune reaction against melanocytes. AIMS: To test this association, we reviewed clinical and histological features of 266 cases of vitiligo and 74 cases of LS in a concurrent study of both diseases. METHODS: All outpatients seen in our department between 2003 and 2006 and who were diagnosed as having LS or vitiligo on the basis of clinical and pathologic features were included in the study. RESULTS: Vitiligoid lesions were seen along with stereotypical LS lesions in three patients but all the three lesions had histological features of LS. Oral/genital areas were affected in 57 out of the 74 LS cases and of those, 15 were initially suspected to have vitiligo. These cases with a clinical appearance of vitiligo and histological features of LS were considered as 'vitiligoid LS', a superficial variant proposed by J. M. Borda in 1968. Association of LS was not observed in the 266 cases of vitiligo. CONCLUSION: Exclusive oral/genital depigmentation is a common problem and histological evaluation is essential to differentiate vitiligoid LS from true vitiligo. The association of vitiligo with LS may have been documented due to the clinical misdiagnosis of vitiligoid LS lesions as vitiligo as histological investigations were not undertaken in any of the reported cases.