<prompt> Most common carcinoma is associated with IVC metastasisSmall cell carcinoma lungGastric adenocarcinomaRenal cell carcinomaPapillary carcinoma thyroid  <response>: Ans is c i.e. Renal cell carcinoma The one of the striking characteristics of RCC is to invade renal vein and metastasize into IVC.Through bloodRenal cell carcinomaPheochromocytomaAdrenocoical carcinomaUterine sarcomas Lemmyomatosis, endometrial stromal cell sarcomaGerm cell tumors embryonal, teratocarcinomaDirect invasionRetroperitonel soft tissue tumors hposarcoma, leipmyosarcoma, malignant fibrous histiosarcoma Hepatic tumors cholangiocarcinoma, HCCPancreaticodudenal tumor. 