Visual Diagnosis: Multiple Falls and a Pigmented Skin Lesion in a 5-year-old Boy

Presentation

A 5-year old boy is transferred from an outside institution for a radiograph finding of a left femur fracture coursing through a lytic lesion. The boy presented earlier that day with left leg pain and inability to bear weight after tripping and falling. One month previously he was diagnosed as having a left tibia fracture after another child jumped and landed on him in an inflatable bounce house. Before these injuries he had no history of bone pain or muscle weakness. His parents report a long-standing history of poor appetite and hyperactivity. He has no associated fever, weight loss, rash, or night sweats. The medical history includes a recent diagnosis of attention-deficit/hyperactivity disorder (ADHD), a “Mongolian spot” diagnosed in infancy, and 3 hospitalizations in the first 4 months of life for brief resolved unexplained events. An investigation for nonaccidental trauma was initiated at that time and revealed chronic bilateral subdural hemorrhages on magnetic resonance imaging, normal laboratory results, and a normal skeletal survey and ophthalmic examination findings. The boy was temporarily placed in the care of a family friend and eventually placed back into his parents’ custody.

On physical examination the boy points to his left thigh as the primary source of pain. He has a posterior long bone splint on the left leg, with an overlying short hard cast that was placed by the outside institution. Range …