Adenomyosis is a condition where the inner lining of the womb (endometrium) is abnormally embedded in the muscle layer of the womb ( myometrium).
During menstruation, this misplaced tissue also bleeds causing surrounding muscle layers to become reactive and thickened. As a result, the whole womb gets enlarged giving rise to symptoms of heavy and painful menses.
Adenomyoma is a localised form of adenomyosis where only some parts of the womb are swollen. This condition can mimic uterine fibroid on ultrasound examination which is just a simple growth in the myometrium.
The differentiation between adenomyosis and uterine fibroid is further complicated by the fact that both can coexist in the same patient .and present similar symptoms.