A 57-year-old woman comes to the clinic due to worsening fatigue and abdominal distention over the past 2 months. The patient has felt increasing fatigue, early satiety
, and has lost 4.5 kg (10 lbs) without changes in diet. Medical history is notable for diabetes mellitus type 2
managed with metformin
. The patient’s last Pap smear
6 months ago was normal. Vitals are within normal limits. On physical examination, bilateral adnexal masses are palpated. The vaginal
exam shows no abnormalities. Abdominal examination shows distention and shifting dullness. Hemoglobin level is 9 g/dL. Histological analysis of the masses would most likely reveal which of the following?