What is adenomyosis?

Updated: Dec 07, 2018
  • Author: Karen L Reuter, MD, FACR; Chief Editor: Eugene C Lin, MD  more...
  • Print
Answer

Answer

Adenomyosis is a benign condition of the uterus caused by a proliferation of endometrial glands and stroma leading to ill‐defined lesions within the myometrium. The displaced glands cause spiral vessel angiogenesis and smooth muscle hyperpalsia and hypertrophy. Thickening of the junctional zone and uterine enlargement can result. Causes include invasion of endometrial glands into the myometrium, displaced pluripotent mullerian remnants, invagination of the endometrium through the basalis along lymphatics, and displaced bone marrow stem cells. [1] On the basis of myometrial invasion extension, adenomyosis  can be classifed as either diffuse or focal. In the diffuse type, endometrial glands and/or stroma are extensively intermingled with myometrial muscle fibers, with an increase in uterine volume (proportionally correlated with the extent of lesions); focal adenomyosis is generally a single nodular aggregate located in the myometrium. [2]  Patients with adenomyosis can have a range of clinical presentations. The most common symptoms of adenomyosis are menorrhagia, dysmenorrhea, pelvic pain, and uterine enlargement; however, adenomyosis is asymptomatic in one third of cases. [3]  Women with adenomyosis often have other associated gynecologic conditions, such as endometriosis or leiomyomas, therefore making the diagnosis and evaluating response to treatment challenging. [4]  There is an increased risk of adenomyosis in women with increased parity, early menarche, short menstrual cycles, high body mass index, prior dilatation and curettage, and prior cesarean delivery. [1]

Previously, when the diagnosis of adenomyosis required histologic analysis from hysterectomy specimens, the diagnosis was thought to occur primarily in women in their 40s and 50s. Currently, the diagnosis of adenomyosis is more commonly made from hysteroscopic or laparoscopic biopsy in women in their 20s and 30s. [1]

(See the images below.)

Transvaginal sonogram of an enlarged uterus with a Transvaginal sonogram of an enlarged uterus with a thickened posterior myometrium (arrows).
Sagittal transabdominal sonogram of an enlarged ut Sagittal transabdominal sonogram of an enlarged uterus with a thickened posterior myometrium (arrows).
Sagittal magnetic resonance image of an enlarged u Sagittal magnetic resonance image of an enlarged uterus with a thickened posterior myometrium. T2-weighted image without gadolinium enhancement shows a widened junctional zone of 23 mm (arrows) and focal high signal intensity (arrowhead). Same patient as in Images 1 and 2.
Transvaginal sagittal image of the uterus showing Transvaginal sagittal image of the uterus showing indistinct endometrial lining (long yellow arrow) with subcentimeter avascular cyst abutting the posterior endometrial lining (short yellow arrow). Courtesy of Christopher D Scheirey, MD.
Sagittal T2-weighted MRI image (same patient as in Sagittal T2-weighted MRI image (same patient as in previous image) without IV contrast showing a globular hypertrophied uterus (long red arrow) and tiny fluid collection about the endometrial lining, with the short red arrow pointing to the largest one. Courtesy of Christopher D Scheirey, MD.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!