This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological oncology, Subject name: Gynaecology & Obstetrics
[{'content': "The following statements are related to Krukenberg tumour except: \nSelect and explain. \nA. It is always secondary, B. The most common primary site is pylorus of the stomach, C. The tumour is bilateral, D. 'Signet ring' looking cells are characteristic", 'role': 'user'}, {'content': 'Answer: A \nExplanation: <p> -Krukenberg tumor is diagnosed only if it conforms to the following pattern ; Almost bilateral Smooth surfaces Freely mobile in pelvis It retains the shape of normal ovary. The tumors are secondary growth in the ovary and most often arise from a primary carcinoma of the stomach(70%). Histologically, the tumor has a cellular or myxomatous stroma amongst which are scattered large signet ring cells. Reference : Shaw&;s textbook of gynaecology, 16th edition, pg no:524 <\\p>', 'role': 'assistant'}]