Automated selection of the most epithelium-rich areas in gynecologic tumor sections

The paper describes an image analysis technique for automated selection of the epithelium-rich areas in standard paraffin tissue sections of ovarian and endometrial premalignancies and malignancies. Two staining procedures were evaluated, Feulgen (pararosanilin) and CAM 5.2, demonstrating the presence of cytokeratin 8 and 18; both were counterstained with naphthol yellow. The technique is based on the corresponding image processing method of automated estimation of the percentage of epithelium in interactively selected microscope fields. With the technique, one image is recorded with a filter to demonstrate where epithelium and stroma lie. This filter is chosen according to the type of staining: it is yellow (lambda = 552 nm) for Feulgen and blue (lambda = 470 nm) for anticytokeratin CAM 5.2. When stroma cannot be distinguished from lumina with the green filter or from epithelium with the blue filter, a second image is recorded from the same microscope field, with a blue filter (lambda = 420 nm) for Feulgen and a yellow filter (lambda = 576 nm) for anticytokeratin CAM 5.2. Discrimination between epithelium and stroma is based on the image contrast range and the packing of nuclei in the yellow image and on the automated classification of the gray value histogram peaks in the blue image. For Feulgen stain the method was evaluated on 30 ovarian tumors of the common epithelial types (8 borderline tumors and 22 carcinomas with various degrees of differentiation) and 30 endometrial carcinomas of different grades.(ABSTRACT TRUNCATED AT 250 WORDS)