Muscle biopsy: a diagnostic technique that remains useful despite advances in genetics

Italian researchers have examined the diagnostic value of muscle biopsy at a time when high-throughput sequencing (NGS) and immunoassays are increasingly relegating it to a second-line investigation:

• a retrospective study was conducted on 401 muscle biopsies referred to the Department of Pathology at Naples University Hospital between 2015 and 2025,
• taking into account, amongst other parameters, the initial clinical suspicion, the biopsy findings, and the final diagnosis at the patient’s last follow-up appointment,
• although only 42 per cent of diagnoses were concordant in the first phase, the concordance rates obtained ultimately were far more encouraging,
• the authors also emphasise that a biopsy interpreted as entirely normal allows, with a high degree of certainty, the diagnosis of primary neuromuscular disease to be ruled out.

This research does not call into question the role of muscle biopsy as a second-line investigation, but serves as a reminder that it can be useful in specific cases (treatable inflammatory conditions, validation of variants identified by NGS, etc.).