An Atypical Case of Chiari II Malformation Mimicking Partial Rhombencephalosynapsis

Partial rhombencephalosynapsis in the presence of Chiari II malformation has been proposed as a "new abnormality of the hindbrain and spine". We describe a case of Chiari II malformation with imaging features mimicking partial rhombencephalosynapsis. Our case demonstrates how the imaging findings of Chiari II malformation can be confused with the above entity and highlights the differentiating features to help radiologists make an accurate diagnosis.