Most common site of metastasis of choriocarcinoma is:

FIGO- staging of gestational trophoblastic disease: Stage 1 - disease confined to uterus Stage 2 - disease extending outside the uterus but confined to genital structures (adnexa, vagina, broad ligaments) Stage 3 - disease extending to the lung, with or without known genital tract involvement Stage 4 - disease at other metastatic sites most common site of metastasis of choriocarcinoma is lung and is classified as stage 3