The 2 stromal compartments of the normal cervix with distinct immunophenotypic and histomorphologic features.

Cervical plasticity is partially attributed to subepithelial stromal cells. Knowing this population of cells in its variable physiologic states, with its immunophenotypic variations, will lead to better understanding of neoplastic processes related to these stromal cells. We reviewed slides of cervices from premenopausal, postmenopausal, and postpartum patients and used mesenchymal immunohistochemical stains. Results demonstrate 2 distinct subepithelial compartments, within the ectocervix and the endocervix/transformation zone. The endocervix/transformation zone has twice the number of stromal cells as the ectocervix, regardless of age. Ectocervical stromal cells are desmin+/smooth muscle actin (SMA)-, and endocervical stromal cells are desmin+/SMA-. In postpartum/premenopausal patients, the cervix has less desmin+ ectocervical and SMA- endocervical cells. In postmenopausal/prolapse patients, the cervix has no desmin+ ectocervical cells. Desmin+/SMA, calponin, caldesmon, myogenin, myoD1, CD34- cells could represent unusual myofibroblasts that should not be confused with a neoplastic process, especially if a mass is not present.