HYPOECHOIC FIBROID A fibroid is a benign tumor or neoplasms that appears in the myometrium, wall of the uterus for reasons still unknown, but attributable to hereditary factors, obesity. early menstruation and others. The attribute of HYPOECHOIC refers to that it produces little resonance (little intense echo) when low-frequency waves are fired over the lesion, meaning that the fibroid is liquid, fat or low-density tissue.