Distal inflammatory myopathy: unusual presentation of polymyositis or new entity?
New classification of idiopathic inflammatory myopathy (IIM) defined three major entities, polymyositis (PM), dermatomyositis (DM) and sporadic inclusion body myositis (s-IBM). We report the clinical, electrophysiological and pathological characteristics of three patients with a rare form of IIM not fulfilling the diagnostic criteria for any of these three major entities. The three patients presented with a subacute, distal asymmetrical weakness in upper limbs. Muscle biopsy showed an active myositis, with necrosis and regeneration, T cell infiltrates with invasion of non-necrotic fibers, without rimmed vacuoles, and diffuse major histocompatibility complex-I (MHC-I) immunostaining in muscle fibers. All patients responded to immunosuppressive agents. Seven others cases were identified in the literature. It is important to recognize this atypical presentation as it seems to respond to immunosuppressive agents.
Centre de Référence des Maladies Neuromusculaires Garches-Necker-Mondor-Hendaye, APHP, INSERM U841, CHU Henri Mondor, 51 boulevard du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
Dalia
D
Dimitri
Odile
O
Dubourg
Thierry
T
Maisonobe
Emmanuel
E
Fournier
Brigitte
B
Ranque
Pascal
P
Laforêt
Jean-Marie
JM
Mussini
Christian
C
Pagnoux
Anthony
A
Béhin
Thomas
T
Papo
Olivier
O
Benveniste
Bruno
B
Eymard
Serge
S
Herson
D015703:Antigens, CD / Q000378:metabolism; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009220:Myositis / Q000150:complications* / Q000473:pathology; D017285:Polymyositis / Q000209:etiology* / Q000473:pathology; D012189:Retrospective Studies
D015703:Antigens, CD