12th May 2024

A 58-year-old woman presents with postmenopausal bleeding, pelvic discomfort, and a recent unexplained weight loss.

A 58-year-old woman presents with postmenopausal bleeding, pelvic discomfort, and a recent unexplained weight loss. Her medical history includes obesity, hypertension, and a family history of Lynch syndrome. An ultrasound reveals a thickened endometrial lining, and an endometrial biopsy confirms endometrioid adenocarcinoma. MRI imaging shows extension of the tumour into the myometrium but no evidence of distant metastasis.

Which is the most likely route by which this tumour spread to the myometrium?