Binovular follicles in the adult human ovary

The human ovary may contain binovular or polyovular follicles at birth, but they are unusual later in life. Binbovular follicles were found in bilateral ovarian biopsies from a patient with primary amenorrhea who had been treated with exogenous gonadotropins. The fine structural morphology of these follicles has shown that both oocytes were in the resting meiotic prophase, that their respective vitelline bodies faced each other across the intervening plasma membranes, and that the adjacent oocytes made mutual contacts similar to those found between granulosa cells and oocytes. From the appearance of the multivesicular bodies in nearby stromal fibroblasts it is suggested that these follicles had formed by fusion of two adjacent primordial follicles by a mechanism similar to the depolymerization of the ground substance in the apex of the Graafian follicle that leads to ovulation.