A 61-yr-old Caucasian female patient was investigated because of right-sided pleuritic chest pain. The patient had a 2-month history of chronic, nonproductive cough, extreme fatigue, night sweats and reduced exercise tolerance. Initially, the patient was treated with antibiotics for presumed pneumonia. She had smoked for .20 pack-yrs and her medical history included parotidectomy for Warthin tumour, resection of a benign cyst in the left breast and varicectomy.Physical examination showed no clinical signs of respiratory distress. Sinus rhythm was present with a heart rate of 88 bpm and blood pressure of 135/80 mmHg. Cardiopulmonary auscultation revealed no significant abnormalities and there was no hepatomegaly or limb oedema. No lymphadenopathy was found in the neck, supraclavicular, axillary or inguinal regions.The laboratory results showed an elevated C-reactive protein of 5.02 mg?dL -1. Low haemoglobin and haematocrit values were in keeping with anaemia. Studies of coagulability were all within normal ranges. Arterial blood gas analysis while breathing ambient air showed an arterial oxygen tension of 66 mm Hg, carbon dioxide arterial tension of 40 mmHg, pH of 7.43 and arterial oxygen saturation of 94%. Pulmonary function tests revealed a mild restrictive defect with a reduced diffusing capacity.A chest radiograph ( fig. 1) and computed tomography (CT) scans (figs 2 and 3) were performed and the patient underwent bronchoscopy and mediastinoscopy. Bronchoscopy revealed no endobronchial involvement. Subsequent biopsies were all found to be negative.All accessible lymph nodes in the superior mediastinum and the region of the right mainstem bronchus were biopsied by cervical mediastinoscopy. Extensive unilateral mediastinal fibrosis was present around the right pulmonary artery and mainstem bronchus.Subsequently, the patient underwent thoracoscopy to obtain a more precise diagnosis. However, extensive inflammation and multiple dense adhesions rendered appropriate investigation impossible, even after opening of the pericardium. Conversion to a limited thoracotomy was performed. Operative findings were general hepatisation of the right lung and nodular lesions in the right lower lobe, which were resected by wedge excision. Central biopsies were also taken.Despite these investigations, a final diagnosis could not be obtained. As the right lung was afunctional, an intrapericardial pneumonectomy was performed and definitive pathological examination revealed the final diagnosis (figs 4 and 5).