Intracranial endodermal sinus tumors associated with growth hormone replacement therapy in a girl.

The primary intracranial endodermal sinus tumor (EST) is regarded as a rare histological subtype that is often associated with components of other germ cell tumors, and there are no reports on the onset of intracranial ESTs after growth hormone (GH) replacement therapy. The authors report an extremely rare case of pure primary EST associated with GH replacement therapy. A 15-year-old girl with GH deficiency experienced headache, nausea, and vomiting after GH replacement therapy for a 17-month period. Magnetic resonance imaging showed 2 tumor masses located in the pineal region and frontal horn of the right lateral ventricle, respectively. Before surgery, the authors administered 1 cycle of neoadjuvant chemotherapy, which shrank the tumor and facilitated surgical intervention. The larger mass located in the pineal region was removed via a right occipital transtentorial approach, and postoperative histopathological analysis revealed a pure EST. While there is a clear association between the initiation of GH replacement therapy and the development of the EST in this case, the causal effect cannot be specified. Nevertheless, this case demonstrates that GH replacement therapy must be used cautiously.