Adenomyosis is a uterine disorder. The uterus basically has two layers, the endometrium and the myometrium. The inner layer is the endometrium, and this layer thickens each month and is shed in the form of a menstrual period. The outer layer is called the myometrium and is the muscular layer. The myometrium contracts to expel the blood from the uterus which can be felt in the form of menstrual cramping. This muscular layer also contracts during childbirth. In a normal uterus, these two layers are distinct and separate from each other.
In adenomyosis, however, the endometrial layer invades the myometrium. When a woman who has adenomyosis has her menstrual period, the pain can be severe because some of the blood is trapped inside the uterine muscle. At the current time, a clear cause for this invasion of the endometrium into the myometrium is unknown. The condition is not life threatening although at times it may feel like it!
Adenomyosis that is spread sporadically throughout the uterine muscle is referred to as “diffuse adenomyosis”. This type is currently very difficult to pick up both on physical exam and on radiological imaging. During a pelvic exam, the doctor might identify the uterus as being soft, tender or slightly enlarged. Also the uterus becomes heavier with more diffuse involvement. During surgery, the uterus may appear completely normal since the adenomyosis is entirely encased within the uterine muscle.
In some cases, an adenomyoma may be present. This is actually better in terms of diagnosis and treatment. An adenomyoma can be felt as a mass during a pelvic exam and can be more easily picked up on radiological exams. In fact, these adenomyomas are often misdiagnosed as fibroids (leiomyomas). Also, it is important to know that 80% of cases also have another uterine disorder present as well such as endometriosis.
In general, adenomyosis represents a challenge in terms of diagnosis and treatment. The only known cure for this disorder currently is hysterectomy, although some new and promising diagnostic methods and treatments are on the horizon including MRI and MRgFUS (see “Adenomyosis Treatments” in the blog). Much more research and education needs to be done to help those who are currently suffering from this disorder.