Histopathologic examination can sometimes provide unexpected indications. In this report giant cell arteritis of uterine vessels was found. It permitted to explain biological abnormalities presented by the patient who suffered of a particularly inflammatory syndrome. These abnormalities had been initially attributed to repetitive urinary infections due to third-degree uterine prolapse (associated bladder prolapse). The diagnosis of periarteritis nodosa (P.A.N.) was supported with the results of muscular biopsy. This diagnosis was confirmed by evolution: it showed secondary renal and hepatic damages. Finally three months after corticotherapy was undertaken, the general state was very improved.