Growing teratoma syndrome following primary ovarian immature teratoma: two cases and review of literature

Growing Teratoma Syndrome (GTS) is defined as the occurrence of a tumor mass consisting exclusively of mature teratoma, combined with normal tumor marker levels, during or after chemotherapy in patients with Non Seminomatous Germ Cell Tumors (NSGCT). We report two cases of GTS. Case 1 is a woman with concomitant retroperitoneal mass invading the muscular layer of abdominal wall, and scattered nodules fixed on the diaphragm following a primary ovarian immature teratoma within 9 months during chemotherapy. No macroscopic deposit was left at the end of last surgery, and pathologic diagnosis showed mature teratoma. The serum level of CA19-9 elevated through the course of disease even four months after the radical operation of GTS when blood amylase and CT scan were negative, and electronic gastroscopy showed chronically congestive and exudative gastritis. We consider the elevated CA19-9 is mainly due to gastritis or only reactive peritoneal mesothelial cells. Case 2 is a woman with scattered nodules fixed on the pelvic peritoneal following a primary ovarian immature teratoma within 3 months during chemotherapy, which is proved to be mature teratoma with mature gliacyte by pathologic diagnosis. The tumor markers are all negative after that and another ovarian mass is found 6 months later. We also reviewed relevant literature and distinguished GTS from chemotherapeutic retroconversion (CR), and gliomatosis peritonei (GP). Optimal cytoreduction with no macroscopic residual disease is essential for GTS with subsequent favorable prognosis. Regular follow-up is recommended.