Multicentric nature of vulvar carcinoma in situ.

A detailed histologic and DNA-microspectrophotometric study is presented of 31 lesions selected from 12 of 65 patients with vulvar carcinoma in situ whom the authors have seen. In 6 patients the lesions were multicentric and in 6 they were confluent. The purpose of the study was to determine whether or not there was a measurable biologic difference between these 2 distinctly different clinical lesions that would justify separating them into different categories. A hypothesis as to the clonal evolution of multicentric and confluent vulvar carcinoma is presented based on the authors' findings.