A 13-year-old boy comes to the office for evaluation of worsening scoliosis. He lost the ability to walk a year ago and has since been wheelchair bound. He has significant back pain and difficulty sitting in his wheelchair for extended periods. The patient also feels "too weak" to cough or take a deep breath. Review of medical records shows genetic studies confirming a mutation of the dystrophin gene on X chromosome p21. Histopathology of the patient's calf most likely indicates which of the following findings?

Question

A 13-year-old boy comes to the office for evaluation of worsening scoliosis.  He lost the ability to walk a year ago and has since been wheelchair bound.  He has significant back pain and difficulty sitting in his wheelchair for extended periods.  The patient also feels "too weak" to cough or take a deep breath.  Review of medical records shows genetic studies confirming a mutation of the dystrophin gene on X chromosome p21.  Histopathology of the patient's calf most likely indicates which of the following findings?

Quizplus · Accepted Answer

Eductional Objective: Duchenne muscle dystrophy manifests with proximal muscle weakness and atrophy.  True hypertrophy of the distal muscle is noted early in the disease as distal muscles compensate for weak proximal ones.  Muscle fibers of the distal extremities are later replaced by fat and connective tissue (pseudohypertrophy).

A 13-Year-Old Boy Comes to the Office for Evaluation of Worsening