[Pitfalls in diagnosis of polymyalgia rheumatica/temporal arteritis]

Polymyalgia rheumatica as well as Horton's disease (arteriitis temporalis) are often diagnosed by exclusion. When either disease is suspected because of certain findings a therapy with glucocorticoids is usually started and initial therapeutic success is commonly seen as indirect proof of diagnosis. Clinical experience, however, shows that both diagnoses may conceal a malignancy. Based on this experience the cases of three patients are reported who's clinical and laboratory findings suggested first manifestations of polymyalgia rheumatica or Horton's disease respectively. During treatment, however, the true underlying disease was revealed in two of the cases. Only in one patient was the diagnosis polymyalgia correct, in the second patient a bronchial carcinoma was found, in the third a carcinoma of the breast with bone marrow carcinosis. All three patients have been presented to physicians participating in a meeting of general medicine in 1999. Before disclosure of the final diagnoses assumptions of the physicians about the initial diagnosis were analysed. The same procedure was used with last year medical students. Physicians had more correct diagnoses (19% had all three correct) than students (only 2.8%). This shows on one hand a marked general diagnostic insecurity concerning the diagnoses polymyalgia and Horton's disease on the other hand it demonstrates the advantage of medical experience gained during practice.