Does an ultrasound that shows nonspecific heterogeneity of uterine myometrial echo texture with a lining measuring 19mm & 2.7cm ovarian cyst necessarily require a biopsy?

Based on the limited information provided, the answer for the need for biopsy is No. But you need to provide more details such as the background of history as to why was the ultrasound done in the first place?

Myometrial texture may vary using ultrasound as a diagnostic measure. If the ovarian cyst is not complex, it can be checked again in a year with another ultrasound. The myometrial texture heterogeneity" may be secondary to "fibroid" tumors or "adenomyosis", and close folowup is advised. Your GYN physician will provide guidance.