[Recurrent pericarditis revealing a systemic sarcoidosis]. / Péricardite récidivante révélant une sarcoïdose systémique.

INTRODUCTION: Sarcoidosis is a systemic granulomatous disorder of unknown cause, mainly involving the lung and the mediastinum. Involvement of the pericardium and peritoneum is rare, but can be the first manifestation of the disease. CASE REPORT: A 55-year-old female patient was followed-up for a recurrent "idiopathic" pericarditis. Diagnostis was challenged when she secondarily presented with enlarged hilar and mediastinal lymph nodes associated with pulmonary "nodules". Imaging with (18)F-FDG positron emission tomography with computed tomography showed multiple hypermetabolic foci in the mediastinum and peritoneum, which suggested a malignant disorder. Finally, histopathological evaluation of the peritoneal nodules revealed a sarcoidosis. A corticosteroid therapy was initiated and disease course was favourable. CONCLUSION: This case report highlights the importance of a unique explanation for a patient presenting with recurrent pericarditis associated with a systemic disease. Although rare, sarcoidosis should be discussed and diagnostic procedures should be performed to obtain histological confirmation.