Detection of Cervical Neoplasia???Reducing the Risk of Error

In cytology studies false negative smears range from 1.8% to 20% due to different levels of cytologic expertise and of material presented to the pathologist. Only 6% of in situ carcinomas of the cervix have an abnormal gross appearance so routine multiple biopsies are needed. Schillers test using a weak aqueous solution of iodine leaves an area of carcinoma unstained but colors normal cervical epithelium a dark brown. However not all areas which fail to stain represent foci of cancer. Multiple biopsies and endocervical curettage are required particularly to detect lesions not involving the portio. Conization is the most accurate method for evaluating the suspicious cervix. 80 histo logic sections should be examined from each cervix specimen. Complicati ons of conization may be hemorrhage cervical stenosis uterine perforation and pelvic infection. Only after 4-6 weeks does pelvic infection cease to be a significant risk. When done during pregnancy conization may cause a fetal loss of 15%. Colposcopy has a low false-negative rate but cannot detect lesions inside the cervical canal. It is the best method of clinical evaluation of patients with abnormal cytological smears particularly during pregnancy. A colposcopic diagnosis is based on an evaluation of vascular pattern intercapillary distance surface contour color tone and clarity of demarcation. Where colposcopic examination is unsatisfactory and cytology is positive conization is indicated. The final diagnosis depends on the histology of the directed biopsy.