Summary

A 63-year-old woman presented with a 4-week history of vulval bleeding. On examination, an 8 mm fleshy irregular vascular lesion was present on the vulva in the periclitoreal area. This vulval lesion was treated by surgical excision. Histological analysis showed irregular pieces of skin partly covered by hyperplastic squamous epithelium. There were areas of fistulous-like endophytic proliferations lined by hyperplastic squamous epithelial cells. The intervening stroma showed granulation tissue with severe active chronic inflammation. At least five hair follicle shafts surrounded by foreign body type giant cells were also identified within the inflamed area. There was no evidence of dysplasia or malignancy. This chronically inflamed fistulous tract together with hair shafts within the wall of the tract were diagnostic of a pilonidal sinus of the vulva. This case report summarises the importance of diagnosing pilonidal sinus at an unusual location.