Welcome @cjacobs99, I added your discussion to the Gynecologic Cancers group here: https://connect.mayoclinic.org/group/gynecologic-cancer/
I did this so that you can connect with other women who have uterine cancer and/or uterine leiomyosarcoma like @rred @ventibug @naturegirl5 and others.

The exact cause of uterine leiomyosarcoma is unknown. They often occur spontaneously, for no apparent reason. Uterine leiomyosarcomas commonly grow quickly. It's natural to want to find a reason why this happened and to find things to blame, like COVID, lifestyle, past exposures, etc. But you can make yourself crazy trying to find the cause. Sometimes cancer just happens. It sucks.

Did they say what stage your cancer was? Will you need additional treatment like chemo or radiation? How are you feeling?