Physiological Metaplasia on the Human Cervix Uteri

Summary: Tissue from the columnar‐covered area of the cervix of women, removed at the first postnatal visit (about 6–7 weeks after delivery) was subjected to the following histo‐chemical procedures: the PAS technique for demonstration of the basement membrane and of mucin, the acid phosphatase technique (studied by both light and electron microscopy) and the DDD technique for the demonstration of SH groups. The variability in structure extending to complete absence of the basement membrane at certain stages of the process of metaplasia is described. The significance of the intimacy of the epithelial and subepithelial tissues at these stages is discussed from the viewpoint of a possible inductive effect analogous to embryonic induction. Columnar cell mucin was noted to be absent in cells of more prominent or superficial situation and toward the vaginal end of the cervical canal. Acid phosphatase labelling of this tissue is shown to occur in columnar epithelial cells and in plasma cells of the subepithelial tissue. Such epithelial staining is, as with mucin, markedly reduced on prominences, e.g., the tips of villous processes. An hypothesis is developed that lysosomes of columnar cells which are responsible for some of the acid phosphatase stain are ruptured by conditions associated with the alteration of the prevailing pH at the cervico‐vaginal junction. Such rupture may in turn damage the columnar cells, depleting their mucin content, and stimulate the production of new (squamous) cells. A gradation of staining with the DDD reagent for SH groups in plasma cells, which are plentiful in sites of active metaplasia, suggests that there is a maturation process at these sites where plasma cells are stimulated to produce antibody. Some part of the plasma cell function appears to be production of antibody and the possible reasons for its production are discussed.