Abstract
The case history of two patients with myopathy, histologically diagnosed as myositis is reported. in both cases the physical signs, the course and later recognized familial cases gave the diagnosis progressive muscular dystrophy. in one case abortion was undertaken on medical, not on eugenic indication, and in the other a genetic counselling, based on the histologic diagnosis, led to the birth of a child who later developed clinical dystrophy. the histological criteria of polymyositis are discussed, and it is concluded that the histologic evaluation must be included in the overall diagnostic considerations, but should not be ascribed final importance.