I had a hysterectomy and removal of my tubes and ovaries. However, two years later, I had a very painful area in my pelvis and was told that I had endometriosis. Is this possible?

Endo post Hyst. Removal of the uterus tubes and ovaries is not curative for endometriosis if the endometriosis was not removed at the time of surgery. Even then microscopic foci of endometriosis could regenerate down the road and cause pain. Now I would like to remind you that there are other conditions that may cause pain not related to endometriosis, such as interstitial cystitis, pelvic floor spasms.
It shouldn't be. If you had your ovaries removed completely your body should not be producing any of the hormones that could stimulate new endometriosis or old endometriosis to cause pain. However, if you are taking hormone remplacement therapy it is possible but unlikely still I would look for other causes of pain first. Have your gynecologist check an FSH level to see if any ovarian tissue may still be present.