Growing Teratoma Syndrome as Retroperitoneal Mass: Case Report

Growing Teratoma Syndrome (GTS) is characterized by the enlargement of tumors during or after chemotherapy for nonseminomatous germ cell tumors accompanied by the normalization of previously elevated tumor marker levels and the presence of mature teratoma components upon histological examination. We present a case involving a 25-year-old male diagnosed with a Mixed Germ Cell Tumor. The patient underwent surgery and chemotherapy. However, a year later he was diagnosed with Growing Teratoma Syndrome (GTS) due to the presence of a retroperitoneal mass that failed to respond to a second regimen of chemotherapy.