Posterior mediastinal teratoma presenting as an abdominal mass in a child: A case report.

We report the case of a 2.5-year-old child admitted for abdominal distension, whose imaging revealed a large posterior mediastinal cystic mass, with a tissue component, a calcification, and a minimal fat component. The ultrasound- guided biopsy led to the diagnosis of a benign extragonadal germ cell tumor, also called mature teratoma or dermoid cyst, whose mediastinal localization is rare, often localized in the anterior mediastinum, and rarely in the posterior mediastinum. The mainstay of treatment is complete surgical excision.