CIN 3 Cervical intraepithelial neoplasia grade 3 (Richart) is a preneoplastic lesion of squamous epithelium corresponding to previous severe dysplasia and squamous intraepithelial carcinoma. Histologically, the proliferation of atypical parabasal cells, oriented in a vertical fashion, involves more than two-thirds. Architectural disorganization, typical or atypical mitotic figures, cytonuclear criteria of malignancy are present in more than the lower two thirds. Keratinization may be present, at the surface or in isolated cells inside the epithelium. Koilocytosis may be observed. Histopathology atlas |