<prompt> Which of the following carcinoma most frequently metastasize to brainSmall cell carcinoma of lungProstate cancerRectal cancerEndometrial cancer  <response>: Ref Harrison 17e p2458; Robbins 8e p1339;7e p1410;9e p1315 Small cell carcinoma of lung most commonly metastasize to brain.it account for about 40 of brain metastasis Other tumors metastasizing to brain are carcinomas of .breast .melanoma .kidney .GIT 