In rare cases, why we see some women are with beard and some men are with breasts ?

This condition can be seen due to overgrowth of Adrenal cortex in male and female .  Adrenal cortex is the outer region of Adrenal gland which secrete sex corticoid hormones (both male and female hormones in an individual). These hormones are similar to male and female hormones secreted by Testis and ovaries. Due to overgrowth of Adrenal cortex in female, male hormones produced in excess will influence the development of mustache, beard  and deep voice in her. Such condition which is caused through overgrowth of Adrenal cortex in females is known as Adrenal virilism (Latin: virilism=maleness). In the case of male, if overgrowth of Adrenal cortex occur, female hormones produced in excess will cause the development of feminine features like development of breast in man.