What is adenomyosis?

Dr. John C. Lipman, MD
Vascular & Interventional Radiologist

To understand adenomyosis, one needs to understand the layers of the uterus. There are 3 main layers of the uterus: endometrium, myometrium and perimetrium. The endometrium is the thin lining of the uterus. It is what sheds with each menstrual cycle resulting in the passage of the menstrual blood. The myometrium is the thickest layer. It comprises the muscular portion of the uterus. The innermost portion of this layer is called the junctional zone (typically only 2-7mm thick). The junctional zone therefore is the transition from the thin uterine lining to the thick muscular uterus. The third layer is the perimetrium which is the thin covering of the uterus. When cells from the lining (endometrium) are found entirely outside of the uterus, it is called endometriosis. When these cells penetrate in to the muscular layer of the uterus (myometrium), this is called adenomyosis (or internal endometriosis). The junctional zone will thicken (>8mm) and can result in enlargement of the entire uterus.

Adenomyosis is when endometrial tissue implants inside the muscle of the uterus.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.