Obstetrics and Gynaecologymiddle twist
A 31-year-old woman presents with two days of right iliac fossa pain and light vaginal spotting. Her last menstrual period was six weeks ago and a home pregnancy test is positive. Her pulse is 82/min and blood pressure 118/76 mmHg, and there is mild right iliac fossa tenderness without guarding. Transvaginal ultrasound shows an endometrial thickness of 13 mm with no gestational sac, a 25 mm inhomogeneous mass adjacent to but separate from the right ovary, and a trace of free fluid in the pouch of Douglas. Serum beta-hCG is 3400 IU/L. Which one of the following is the most likely diagnosis?