Growing teratoma syndrome: first case report in a 4-year-old girl.

Growing teratoma syndrome (GTS) consists of germ cell tumors that grow following chemotherapy despite complete eradication of the malignant cells. They can metastasize to any site, particularly the retroperitoneum, mediastinum and cervical region. It typically affects young adults and adolescents. Here we describe the youngest case reported in a 4-year-old girl with an ovarian mixed germ cell tumor who underwent an oophorectomy. Her tumor markers normalized by the end of her chemotherapeutic treatment; however, she developed a retroperitoneal mass that was subsequently resected. Histopathology revealed a mature teratoma, consisting of a GTS. We stress the need for early recognition and treatment of GTS to avoid the subsequent morbidity and mortality associated with it. Although GTS has an excellent prognosis when completely resected, it is essential that the patient be regularly followed-up with serum tumor markers and imaging.

Renal medullary carcinoma in a white adolescent with sickle cell trait.

Renal medullary carcinoma (RMC) is a rare neoplasm of the kidney that has been recently described. It is almost exclusive to young patients of African descent and associated with sickle cell hemoglobinopathy, mainly sickle cell trait and hemoglobin sickle cell disease. The prognosis of RMC is very poor because of the highly aggressive behavior of this neoplasm and its resistance to conventional chemotherapy. Metastatic disease is almost universal at the time of presentation, and the malignancy is minimally responsive to a variety of regimens and/or modalities, including surgery, radiotherapy, chemotherapy, and biological immune-modulation therapy. We report the seventh case of a left RMC occurring in a white child with sickle cell trait, but with a localization of the tumor in the left kidney, considered a nonpredominant side for this type of tumor.