The Mature Ovarian Teratoma: Sign of the Poké Ball

The "Poké Ball sign" is a distinctive radiological feature observed in mature cystic ovarian teratomas. It is characterized by the presence of a spherical structure floating at the interface between fat and fluid, resembling a Poké Ball (Figure 1) [1]. In the Pokémon® series, a Poké Ball is a spherical device utilized for capturing and containing Pokémon [2].