Cytology of vulvar squamous neoplasia.

Cytologic findings on various vulvar squamous lesions are described in order to elucidate the usefulness of vulvar cytology. Lichen sclerosus, hyperplastic dystrophy and dysplasia with a few exfoliated anucleate squamous cells could not be differentiated cytologically. Numerous parakeratotic cells and dyskaryotic cells were identified in squamous cell carcinoma in situ. Three cytologic patterns were presented in cases of frankly invasive squamous cell carcinoma: negative cytology with parakeratotic cells, suspicious cytology with dyskaryotic cells and positive cytology with malignant cells. Verrucous carcinoma yielded only anucleate squamous cells. Parakeratotic cells without nuclear atypia seemed to be neoplastic cells on vulvar cytology.