Treatment for bulky uterus 10.7cm long axis 5.3cm thick, normal adnexas?

Depends: In general no treatment for a uterus that is just bulky. It really depends on why you had the ultrasound and what your plans are for children. Mild uterine enlargement is often times associated with adenomyosis and fibroids, but can also be seen in an early pregnancy before the gestation is visible. More info is really needed to answer your question.