A rare autoimmune disorder in which patients present with overlapping symptoms of systemic scleroderma and polymyositis or dermatomyositis. The disease or phenotype is EFO_1001994 (Scleroderma Polymyositis Overlap Syndrome). Also known as: polymyositis in scleroderma, scleroderma/polimyositis overlap, scleromyositis.