[Steroid-sensitive cavitating pulmonary opacity in Horton's disease].

We report the case of a 72 year old woman treated for seven months for Horton's disease presenting with a cavitating pneumonia of the left axillary segment associated with a deterioration of the general state, at the time of which the steroid therapy was in the course of being decreased. The radiological appearance and the clinical context of immune depression had led to a trial of a quadruple anti-tuberculous therapy in spite of the absence of any bacteriological proof. This rapid aggravation of the condition under treatment led to the suggestion of a pulmonary localisation of Horton's disease. The rapid regression of the lesions after increasing the dose of steroids and the negative cultures on Lowenstein medium pleaded in favour of this hypothesis. However the continuation of anti-tuberculous treatment seems justified in such cases in so far as the diagnosis of Horton's disease of the lung often cannot be maintained other than retrospectively in the absence of histological proof.