<prompt> Most common cause of brain metastasis is?Carcinoma lungProstate cancerHCCSeminoma  <response>: Ans. is a i.e., Carcinoma lung Metastasis to brain are the most common brain tumor. Most common primary malignancy metastatizing to brain is lung carcinoma, followed by in decreasing order of frequency breast, skin melanoma, kidney genitourinary and GIT cancers. Prostate carcinoma, ovarian carcinoma and Hodgkins disease are very unlikely to metastatize to brain. 