Grading cervical dysplasia with AgNORs using a semiautomated image analysis system

: Colposcopic biopsies were classified according to previously established criteria by a group of three pathologists interested in cervical pathology. Ten cases were identified in each of the following five groups: normal, koilocytosis, low grade squamous intraepithelial lesions (CIN 1), high grade squamous intraepithelial lesions (CIN 2) and high grade squamous intraepithelial lesions (CIN 3). The Crocker technique was used to stain the sections cut 3 microns thick. With ths silver stain the nucleolar organizer regions (NORs) are stained black and referred to as AgNORs. It has been shown that malignant and premalignant changes in cells produce an increase in AgNORs. In each case eight images were captured using a 100x oil-immersion objective and stored in a Datacube Maxvideo system as 512 x 480 pixels in an 8-bit grayscale per image. The images were processed using the NeoPath field-of-view computer to detect the AgNORs and nuclei by using grayscale mathematical morphology algorithms. Color overlays of the AgNORs and nuclei were created using segmentation algorithms. The results show that it is possible to differentiate between low grade squamous intraepithelial lesions (CIN 1) and high grade squamous intraepithelial lesions (CIN 2 and CIN 3) taken together; however, there is no difference between low grade squamous intraepithelial lesions (CIN 1) and koilocytosis. The results support the concept that dysplasia cannot be classified effectively into three grades and that low grade squamous intraepithelial lesions (mild dysplasia [CIN 1]) is indistinguishable from koilocytosis.