Brachio-cervical inflammatory myopathy (BCIM) is a rare and under-characterized subtype of idiopathic inflammatory myopathies (IIM), marked by prominent upper limb and neck muscle involvement. Since its initial description in 2006, few studies have addressed its clinical spectrum or pathogenesis, and its potential overlap with systemic sclerosis (SSc) remains a matter of debate. Here, we aimed to characterize the clinical, histopathological, and molecular features of BCIM in a large multicenter cohort and assess whether BCIM constitutes a distinct entity within the IIM spectrum.