Idiopathic granulomatous myositis: does the clinical spectrum include polymyalgia rheumatica?

Granulomatous inflammation restricted to muscle is an uncommon cause of myo pathic syndromes. Two patients were diagnosed with idiopathic granulomatous polymyositis after appropriate investigations failed to reveal a systemic or alternative explanation for the granulomas seen in their muscle biopsy. One patient presented with a syndrome indistinguishable from polymyalgia rh eumatica but both patients manifested disabling myalgias which were strikin gly corticosteroid responsive. The two cases underscore the potential impor tance of muscle biopsy in polymyalgic states, the non-specificity of polymy algia rheumatica as a syndrome which can be simulated by other disorders in cluding granulomatous myositis, and the potential corticosteroid responsive ness of prominent, functionally limiting myalgias which can be seen in this disorder. Some controversy continues regarding the correct nosology of thi s disease, largely perpetuated by an awareness of the inherent limitations of current non-invasive evaluation techniques to confirm occult granulomato us involvement of non-myogenous organs.