205th ENMC International Workshop: Pathology diagnosis of idiopathic inflammatory myopathies Part II 28-30 March 2014, Naarden, The Netherlands.

The idiopathic inflammatory myopathies (IM) are a heterogeneous group of diseases and diagnosis often necessitates a muscle biopsy. Five main entities are recognized: (1) dermatomyositis (DM); (2) polymyositis (PM); (3) necrotizing autoimmune myopathy (NAM); (4) sporadic inclusion body myositis (IBM); and (5) non-specific myositis. Other entities include granulomatous myopathy, macrophagic myofasciitis, and eosinophilic fasciitis (Shulman's syndrome). The pathological classification and subsequent identification of disease subgroups are extremely important for assessing treatment options and prognosis in the individual patient, yet classification criteria have not been standardized and vali…