Ovarian sex-cord stromal tumors Quiz: Ace Your Exams

A 50-year-old woman comes to the clinic due to fatigue and difficulty breathing. The patient is generally healthy, but over the past few months, she has experienced progressive fatigue and dyspnea. She also has noticed an increase in her weight without changes in her diet. Her last menstrual cycle was 2 years ago; since then, she has had some mild hot flashes that have resolved without treatment. The patient’s last Pap smear 2 years ago was normal, and she has no history of a sexually transmitted disease or abnormal uterine bleeding. Family history is noncontributory. Vitals are within normal limits. On physical examination, heart sounds are normal. There are decreased breath sounds at the lung bases bilaterally and dullness to percussion. Abdominal examination reveals shifting dullness but no peritoneal signs. On pelvic examination, a right-sided, non-tender adnexal mass is noted but the rest of the exam is within normal limits. On ultrasound examination, a calcified hypoechoic mass is observed. Based on these features alone, which of the following is the most likely diagnosis?