Calcinosis cutis (CC) is the umbrella term for calcium salt deposition on skin and subcutaneous tissue. We present a unique case of CC associated with anti-Mi2-positive dermatomyositis, having a distinctive distribution of subcutaneous calcifications appearing as a ‘lumbar belt’. Treatment of CC remains challenging for clinicians due to a lack of high-quality evidence. Corticosteroids, methotrexate, bisphosphonates, intravenous immunoglobulin replacement, rituximab and sodium thiosulfate failed to halt calcinosis progression in this case. Newer therapies, such as Janus kinase inhibitors, should be considered.