A case of immune-mediated necrotizing myopathy mimicking FSHD

Swiss clinicians report the clinical and histological data of a 72-year-old adult patient whose clinical presentation initially suggested facioscapulohumeral muscular dystrophy (FSHD):

• the patient suffered from a progressive asymmetric muscle deficit that had appeared three years previously, with associated facial weakness,
• treatment with statins had been started following a stroke which had resulted in paresis of the left upper limb,
• CPKEnzyme contenue dans les cellules musculaires, qui est libérée dans le sang en cas d’atteinte musculaire. levels were normal at the time of the stroke but were found to be very high in the recent period,
• two presumptive diagnoses, one of FSHD and the other of myotonic dystrophy type 2 (DM2), had been considered,
• the additional work-up revealed positive anti-HCMGR autoantibodies, indicating a diagnosis of immune-mediated necrotizing myopathy.

It should be noted that the genetic test for FSHD was not carried out in the patient.

Anti-HMGCR myopathy mimicking facioscapulohumeral muscular dystrophy. Braun AA, Atiya M, Göhner K et al. Open Med (Wars). 2024 Sept.