Diagnostic Value of Muscle MRI in a Case of Very Late-Onset Becker Muscular Dystrophy.

The diagnostic evaluation of myopathies can be challenging, particularly in adults and elderly patients with comorbidities and atypical clinical presentations. While a few hereditary myopathies such as myotonic dystrophy types 1 (DM1) and 2 (DM2) or facioscapulohumeral muscular dystrophy (FSHD) present with sufficiently characteristic phenotypes to allow targeted genetic testing, most patients exhibit limb-girdle weakness with a broad differential diagnosis. In older individuals, acquired conditions—especially idiopathic inflammatory myopathies—are often considered first. But also late-onset hereditary myopathies, including autosomal-dominant and autosomal-recessive limb-girdle muscular dystrophies (LGMDs) as well as the x‑linked rarely late-manifesting Becker muscular dystrophy, which typically presents in adolescence or early adulthood, must be considered.