You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following carcinomas most frequently metastasizes to brain and explain in detail?
Ans. is 'a' i.e. small cell Ca of lung Because of its high blood flow brain is a common site for metastasis. Primary sites in decreasing order are : Lung > breast > melanoma > kidney Prostate Ca, ovarian cancer and Hodgkin's disease rarely metastasizes to brain. (Ref: Harrison I7/e)