[Growing teratoma syndrome].

Growing teratoma syndrome (GTS) is a rare entity, characterized by enlarging masses of the retroperitoneum or other location occurring during or after systemic chemotherapy for the treatment of non-seminomatous germ cell of the testis (NSGCT). Three criteria define this syndrome: enlarging metastatic masses, normalized serum markers and no component of viable germ cell tumor in this mature teratoma. Prognostic is excellent after the resection of these masses, but this surgery has to be as much complete as possible. Surgical excision of large GTS lesions is technically challenging, a serious intraoperative complications may occur, that's why the treatment must not be delayed.