A pediatric chronic subdural hematoma: More than meets the eye

We present an unusual case of a 13-year-old child who following minor head injury presented with what appeared to be a thin chronic subdural hematoma on plain computed tomography imaging. The child was found to have an underlying arachnoid cyst. Intra- and extra-cystic bleeding had occurred simultaneously causing an isodense cyst with an accompanying subdural collection. This radiographically occult pathology should be excluded using magnetic resonance imaging in any child presenting with a subdural collection.