RESUMEN
We report the first known case of an adrenal teratoma containing a Wilms tumor component, in a 12-month-old girl with Trisomy 21. Despite adrenal teratomas being relatively uncommon, this particular instance raises interesting questions regarding the tumor origin, given the coexistence of both a teratoma and a Wilms tumor. Two main theories of development have been hypothesized, one of which suggests that the Wilms tumor may develop from a primary teratoma and the other proposing that the teratoma could originate from a primary Wilms tumor. Our case study leans toward the former, as the majority of the tumor displayed characteristics of a typical mature teratoma, with the Wilms component discovered as an incidental finding. Successful surgical intervention led to the gross total resection of the tumor. Twelve months post-resection, the patient remains free of recurrence. This report contributes to our understanding of these rare tumor types and underlines the importance of identifying the primary tumor to ensure appropriate management and treatment.