Abnormal transformation zone: Colposcopic patterns and histological findings

To evaluate the clinical reliability of colposcopic patterns in relation to histological diagnosis. One thousand cases of colposcopic abnormal transformation zone diagnosed out of 5930 colposcopic examinations were studied. In all cases, target biopsies of suspected lesions were performed. The terminology applied in the interpretation of colposcopic patterns was that proposed by the 1987 Italian classification. For abnormal transformation zone 0, 28 (49.1%) cases were due to human papillomavirus infection. The 764 cases of abnormal transformation zone 1 were distributed as follows: 375 (49.1%) negative histological findings; 301 (39.4%) patterns of human papillomavirus infection and 88 (11.5%) cases of cervical intraepithelial neoplasia of various grade. Of the 179 cases of abnormal transformation zone 2, 34 (19%) were histologically negative; 83 (46.4%) cases showed human papillomavirus infection; 56 (31.3%) cases were cervical intraepithelial neoplasia of various grade and 6 (3.4%) showed invasive carcinoma. The Italian classification enabled us to clearly identify the abnormal patterns that must be subjected to target biopsy.