ABSTRACT
Resistant idiopathic inflammatory myositis (IIM) defines IIM with clinical and/or laboratory findings not responding to immunosuppressive treatment. In the presence of the lack of response to standard treatment modalities, disease related damage, underlying malignancy, undertreatment should be considered besides resistant myositis. Different types of non-inflammatory myopathies that mimics IIM also need to be ruled out in resistant myositis cases. Detailed history, pyhsical examination and laboratory work-up should carefully be re-evaluted. Muscle biopsy performed at initial diagnosis has to be scrutinized in terms of prerequisites of sampling and adequate pathologic evaluation in resistant cases. Taking a new biopsy sample might be needed to exclude the myopathies that mimics IIM.