Vulvar Lichen Planus Presenting as Chronic Vulvar Purpura.

Background: There is a broad spectrum of vulvar pigmented lesions that differ based on their histopathological and clinical features. Chronic vulvar purpura is a rare entity, associated with a broad morphological spectrum, from lichen aureus, Zoon's vulvitis, pigmented purpuric dermatosis and with lichen planus as in our case. Case presentation: In this article we discuss a case of an 86-year-old white woman with hyperpigmentation on her upper vulva, next to the introitus, with complaints of urine incontinence. Biopsy revealed subepithelial stromal lichenoid inflammatory infiltrate containing plasma cells, lymphocytes and some neutrophilic granulocytes as well as dilated and congested vessels. Hemosiderin deposits and erythrocyte extravasation were found. There was evidence of hyperkeratosis with hyper granulosis and erosions. Spongiosis was also noted. Few melanocytes were identified with no sign of malignancy. These findings correlate with the diagnosis of vulvar lichen planus. Conclusions: Chronic vulvar purpura is a clinical term used for different chronic inflammatory dermatoses presenting as red bluish or violaceous discolorations on the vulva, often associated with cayenne-pepper-like speckling. Considering a great overlap of possible diseases, the final diagnosis could be challenging. It is important to exclude a melanocytic tumour in these cases.