A 68 year old woman presents with abdominal distention and pain. Physical examination reveals an abdominal mass with absence of shifting dullness and the presence of induration in the rectal pouch on rectal examination and bilateral adnexal masses. Her breast examination and recent mammogram are normal. She most likely has:-

Serous cystadenocarcinomas are the most common malignant tumors of ovaries and the most common tumors associated with bilaterally. The peak incidence of invasive epithelial ovarian cancer is at about 60 years of age. About 30% of ovarian neoplasms in postmenopausal women are malignant. Malignant ascites and meigs syndrome (both have ascites) are ruled out as there is no shifting dullness. Krukenberg tumors are also bilateral, but are associated with another primary malignancy (most commonly gastric carcinoma) and are also less common compared to epithelial tumours.