I recently had a discharge that looked like skin. it was half the size of my palm. what could this be? could it be cancerous?

Not cancer: If it was a single piece of tissue- probably a decidual cast. This would be most likely if you are on hormonal contraception or have high Progesterone levels. If there were multiple episodes the tissue was vaginal skin -the condition is vaginal desquamation or sloughing of the vaginal skin- kind of like peeling after a sunburn. It indicates a reaction to something, .

See your doc: Where did the discharge come from? I would alert your friendly primary care physician to these symptoms.