Quantitative evaluation of the skin and accessory appendages in vulvar carcinoma in situ

Fifty cases of vulvar carcinoma in situ comprising over 1000 histologic sections were studied. Each case was evaluated to determine the thickness of the neoplastic epidermis and the depth of involved skin appendages. Two precise techniques were used to perform the microscopic measurements. The areas most frequently afflicted with neoplasia were: one or both labia (45%), interlabial folds (27%), perineum-fourchette (15%), and perianal skin (10%). Multicentric disease was observed in 68% of the cases. The epidermal thickness ranged between 0.35-1.66 mm. The mean depth (+/- SD) of the epidermis was 0.93 +/- 0.37 mm. Eighteen of the 50 patients demonstrated involvement of the skin appendages to a mean depth of 1.53 +/- 0.77 mm, suggesting that laser vaporization to a depth of 2.5 mm will, with the anticipated additional thermal necrosis, eliminate appendages involved with carcinoma in situ in 95% of instances. The most common sites of skin appendage involvement were the labia majora or minora and the interlabial folds.