Difference Between Adenomyosis and Endometriosis

Adenomyosis and endometriosis are both due to the presence of endometrial tissue in sites other than the normal uterine cavity. Adenomyosis is a type of endometriosis. These two conditions share many common features, but there are a few fundamental differences too and all those will be discussed here in detail.


The uterus has an inner lining called the endometrium that changes in thickness, blood supply, and other characteristics according to the hormonal signals of hypothalamus, pituitary and ovaries. This lining sheds every month during menstruation. Endometriosis is defined medically as the presence of endometrial tissue at sites other than the normal uterine cavity. Ovaries, tubes, broad ligament, rectum, bladder and pelvic wall are common sites of ectopic endometrial tissue. These ectopic endometrial tissues are also under the direct hormonal control. Due to cyclical changes these abnormal tissues give rise to specific cyclical symptoms and signs. Endometrial deposits on ovaries lead to lack of ovulation, destruction of ova after ovulation, cyst formation and bleeding into these cysts resulting in chocolate cysts. Deposits on broad ligament, pelvic wall, and tubes cause adhesions, which disrupt regular peristaltic movement of tubes. This prevents transport of ova and fertilized ova to the uterus, and subfertility and ectopic pregnancies can result. Endometrial deposits on pelvic wall, broad ligament, tubes, and ovaries can bleed causing irritation of the pelvic peritoneum. This causes pain that starts a few days before menstruation and outlasts menstruation.

Ultrasound scan of the abdomen and pelvis is the commonest diagnostic tests for endometriosis. CA-125, which is a serum marker, may be elevated in endometriosis but rarely goes above 100. Laparoscopy allows direct visualization of endometrial deposits and therapeutic cauterization. Danazol, lupride, oral contraceptive pill, and depo provera injection are hormonal treatment methods for endometriosis.


Adenomyosis is the presence of endometrial tissue inside the muscle layers of the uterus. This results in a uniformly enlarged uterus. There is excessive menstrual bleeding because endometrial tissue interferes with contraction of uterine muscles. There is pain because there is bleeding and irritation of pelvic peritoneum. There may be irregular menstrual bleeding.

Ultrasound scan of pelvis shows enlarged uterus with poor demarcation between the endometrium and the myometrium. Adenomyomectomy, hysterectomy, and hormonal treatment methods are available to treat adenomyosis.

What is the difference between Adenomyosis and Endometriosis?

• Endometriosis usually refers to the presence of endometrial tissue outside the uterus while adenomyosis refers to the presence of endometrial tissue inside the uterus at an abnormal site.

• In endometriosis pain is the main feature while in adenomyosis irregular menstruation is the main feature.

• Pelvic endometriosis causes subfertility much more commonly than adenomyosis.