[Differential diagnosis of "rheumatoid nodules"].

Rheumatic nodules occur in some 20 to 25% of cases of chronic polyarthritis, and need special diagnostic, in particular differential diagnostic, consideration. They have to be differentiated from numerous other nodules in rheumatoid and non-rheumatoid diseases. To achieve this, palpation, a knowledge of the preferred sites, and the use of such technical means as laboratory and x-ray investigations are all useful.