Koilocytosis in dysplastic and reactive cervical squamous epithelium. An ultrastructural study

Koilocytosis was studied in eight cases of dysplasia and reactive atypia with conventional transmission electron microscopy. The ultrastructural features were compared to the process of maturation of normal cervical epithelium. Koilocytosis was observed as abnormal karyopyknosis as represented by irregular nuclei, coarse chromatin clumping, the less dense ellipsoid perinuclear zone, and the increased tonofilament bundles in the outer zone of the cytoplasm accentuating the margin of the perinuclear zone of the cells.