Growing Teratoma Syndrome and Gliomatosis Peritonei in a 15-Year-Old Girl With Immature Ovarian Teratoma: Case Report and Review of the Literature.

Gliomatosis peritonei (GP) is a rare clinical condition characterized by presence of mature glial cells in the peritoneum. Growing teratoma syndrome (GTS) is described as an uncommon phenomenon that could be related to the incidence of non-seminomatous germ cell tumors. We report a case of a patient treated for immature ovarian teratoma, in whom both GP and GTS were observed, an association to date scarcely described in literature. A 15-year-old girl presented to the emergency department with severe pain in her lower abdomen and right lumbar region. Upon admission, concentration of α-fetoprotein (AFP) was 1500 ng/mL and β-human chorionic gonadotropin (β-hCG) less than 2 ng/mL. A computed tomography (CT) scan of the abdominal cavity and pelvis confirmed the presence of an anomalous mass in the abdominal cavity and pelvis. Initial surgery was performed. Histopathology revealed the presence of immature teratoma with epithelial elements. Normalization of AFP was achieved within 8 weeks. Five months after surgery, a progressive increase in AFP was noted. Magnetic resonance imaging (MRI) and CT scans of the pelvis minor showed local relapse. Evaluation of the remission after 2 blocks of preoperative chemotherapy revealed the presence of a large tumor mass in the pelvis minor, despite normalization of the AFP concentration. After opening the abdominal walls, numerous abnormal white nodules were observed in the peritoneum. Histopathology revealed the presence of mature glial tissue (gliomatosis peritonei). The remaining tumor mass was removed, and histopathology confirmed existence of mature teratoma (growing teratoma syndrome). Postoperative chemotherapy was continued. To date, the patient remains under clinical and laboratory remission. Concomitant incidence of GP and GTS, although rare, should always be taken into consideration in pediatric patients with diagnosis of either condition.