From the Guidelines
The cervical stroma is the connective tissue that forms the bulk of the cervix, consisting of dense collagen fibers, elastic tissue, smooth muscle cells, fibroblasts, and blood vessels, as evident in the context of cervical cancer staging where stromal invasion is a key factor in determining the extent of tumor spread 1.
Composition and Function
The cervical stroma is composed of various cell types and extracellular matrix components, including:
- Dense collagen fibers
- Elastic tissue
- Smooth muscle cells
- Fibroblasts
- Blood vessels These components are arranged in a complex three-dimensional network, providing structural support and strength to the cervix. The stroma plays a crucial role in maintaining pregnancy by keeping the uterus closed until labor begins.
Clinical Significance
Abnormalities in the cervical stroma can lead to various conditions, such as:
- Cervical insufficiency (premature cervical dilation during pregnancy)
- Cervical stenosis (abnormal narrowing) The stroma also serves as the site where cervical cancer can develop if abnormal cells invade beyond the epithelial layer into this deeper tissue, marking the transition from pre-invasive to invasive cervical cancer, as described in the staging guidelines 1.
Staging and Treatment
In the context of cervical cancer, the depth of stromal invasion is an important factor in determining the stage of the disease, with stages ranging from IA1 (measured stromal invasion 3.0 mm or less in depth) to more advanced stages 1. Treatment options, such as radical hysterectomy with bilateral lymph node dissection, may be considered based on the stage and other factors 1.
From the Research
Definition and Composition of Cervical Stroma
- The cervical stroma, also known as cervical connective tissue, is the load-bearing portion of the cervix, composed of collagen-rich extracellular matrix 2.
- It is a vital structure for the success of pregnancy, providing mechanical integrity to maintain a healthy gestation 3, 4.
- The cervical stroma is made up of fibrous tissue, with a dense network of collagen fibrils that undergoes radical modification during cervical ripening 4.
Changes in Cervical Stroma during Pregnancy
- During normal pregnancy, the cervical extracellular matrix (ECM) remodels in preparation for labor, with significant increases in total sulfated glycosaminoglycans, hyaluronic acid, and collagen solubility 3.
- The collagenous network of the cervical stroma becomes less organized and more compliant during pregnancy, allowing for the gradual decline in tissue compliance 3, 5.
- The biochemical mechanisms of cervical softening are poorly understood, but it is thought to involve changes in the composition of the ground substance of the cervical stroma, including alterations in the concentration and type of glycosaminoglycans (GAGs) 4.
Mechanical and Biochemical Properties of Cervical Stroma
- The mechanical integrity of cervical tissue is crucial for maintaining a healthy gestation, with altered tissue biochemistry causing drastic changes in the mechanical properties of the cervix 5.
- Cervical stroma has a nonlinear, time-dependent stress response with varying degrees of conditioning and hysteresis, depending on its obstetric background 5.
- The nonpregnant tissue is significantly stiffer than the pregnant tissue in both tension and compression, with higher collagen extractability, sulfated GAG content, and hydration in the pregnant tissue 5.