[Myositis with inclusion bodies: a little-known variety of idiopathic inflammatory myopathy].

The authors report two male patients with inclusion body myositis (IBM) and review the features of this condition in the literature. This is an uncommon type of idiopathic myositis which involves males more often than females; it usually develops in elderly patients; its course is very slow; it is usually associated with distal weakness; neurophysiological studies show a mixed "myogenic" and "neurogenic" pattern; and it is usually unresponsive to corticosteroids. The diagnosis is basically made on the basis of the histological features, mainly consisting of vacuoles surrounded by a basophilic haze in histochemical stains of frozen tissue and, particularly, by the presence of characteristic microfilaments in ultrastructural studies.