Calf pseudohypertrophy is a classic finding in which muscular dystrophy?

• A. Becker muscular dystrophy
• B. Duchenne muscular dystrophy
• C. Limb-girdle muscular dystrophy type 2A
• D. Myotonic dystrophy

Answer: (B)

Calf pseudohypertrophy happens when muscle tissue is progressively replaced by fat and fibrous tissue after ongoing muscle damage. In Duchenne muscular dystrophy, the absence of dystrophin makes muscle membranes fragile, leading to repeated cycles of muscle fiber necrosis and loss. Over time, these fibers are replaced by connective and fatty tissue, so the calves look enlarged even though the muscle is weaker. This combination of early onset, proximal weakness, and prominent calf enlargement is classically associated with Duchenne. Other conditions like Becker dystrophy, limb-girdle type 2A, or myotonic dystrophy can involve weakness, but they don’t present with calf pseudohypertrophy as a defining, classic finding.