A metaplastic squamous epithelium that is glycogen poor (top), adjacent to normal squamous epithelium that is glycogen rich (bottom). The corresponding regions would fail to stain with iodine (top) or would take up the stain (bottom) . The squamous pegs in the lamina propria represent glands replaced entirely by metaplastic squamous epithelium (H&E, x45). The lower half of the photograph illustrates the junction of metaplastic squamous epithelium (left) adjacent to normal squamous epithelium (right). The hyperkeratosis on the left would appear as leukoplakia on colposcopy (H&E, x 250). Image from the NCI publication "An Atlas of Findings of Human Females: After Intrauterine Exposure to DES".