Hi, since you already had a myomectomy done. And i would like to bring to your attention that the causes of fibroid or leiomyioma are many First beng the genetic predisposition, followed by the imbalance of progesterone and estrogen. The pathophsiology of that disease is that the islands of endometrial glands get migrated towards the myometrium in which they grow abnormally When such islands are are umpteen in number and they are too small in in size , on USG the uterus give a diffuse picture whta is meant by the term heterogenous myometrial signal For your knoweledge ensometrium and myometrium are the layers of the uterus These island can grow into large fibroids Take care