Prognosis of vulvar dysplasia and carcinoma in situ with special reference to histology and types of human papillomavirus (HPV).

Sixty-one women with vulvar dysplasia or carcinoma in situ were treated with local laser excision of the initial lesion and of the recurrences, and followed at intervals of from 3 increasing to 12 months. Recurrences were observed in 16 (26%) patients. No case of invasive carcinoma was seen. Patients with recurrences were significantly younger than those without (P < 0.02, median age 42.5 and 54 years, respectively). The resection borders were significantly more often involved in the initial lesions in the group with recurrences (36%) than in the group without (9%) (P < 0.014). All lesions were classified according to the WHO (mild, moderate, severe dysplasia or carcinoma in situ) and Toki et al. (1991) (warty, basaloid, combined warty/basaloid or mixed (warty, basaloid and simple). No pure types of Toki (1991) could be demonstrated. There were no differences regarding recurrences in any of these groups. HPV DNA was detected in the initial lesions by PCR in 50/56 (89%) (44 with HPV type 16 and 6 with HPV type 33) and by ISH in 23/61 (38%). The same type of HPV could be demonstrated in all first recurrences except in two, where HPV types 33 was shown in specimens harboring HPV type 16 in the initial lesions. In one of these cases, HPV type 16 could again be demonstrated in the second and final recurrence. In no specimen was more than one type of HPV detected. The results indicate that the most important parameter in predicting the recurrence of vulvar dysplasia or carcinoma in situ is the involvement of the resection borders. The location of the lesion, the degree and type of dysplasia, and the type of HPV seem to play a minor role. Local excision and subsequent intensive control with removal of any visible new lesion probably prevents development of vulvar invasive carcinoma.