This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological Disorders in Obs., Subject name: Gynaecology & Obstetrics
[{'content': "All are true about Krukenberg's tumor except: \nSelect and explain. \nA. It is always secondary, B. Most common primary is stomach, C. Usually bilaterality, D. Signet ring cells are seen", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. It is always secondaryKrukenberg tumor is generally a metastatic tumor to the ovary. But "Krukenberg tumor may be a primary tumor"The most common primary sites from where metastases to the ovaries occur are gastrointestinal tract (pylorus, colon and rarely small intestine), gallbladder, pancreas, breast and endometrial carcinoma.* These are usually bilateral tumors which maintain shape of the ovary. Histologically \'signet ring\' looking cells are characteristic of Krukenberg tumor.', 'role': 'assistant'}]