causes of complex hyperplasia with atypia
Hormones and the absence of hormones are the causes of complex endometrial hyperplasia. In normal menstrual cycles, the ovaries produce the hormone estrogen in the beginning of the cycle, causing the lining to grow and thicken.ormones and the absence of hormones are the causes of complex endometrial hyperplasia. In normal menstrual cycles, the ovaries produce the hormone estrogen in the beginning of the cycle, causing the lining to grow and thicken.