A massive pleural-based desmoid tumour

A 49-year-old Pakistani male presented with "heaviness" in his chest. Chest radiograph and computed tomography (CT) confirmed a massive left-sided pleural-based opacity. Three years ago, he was investigated for a left-sided lymphocytic, exudative pleural effusion following an episode of dengue fever. Tube thoracostomy removed 1.3 L of fluid. Pleural biopsy and bronchial washings were non-contributory. He received empirical anti-tuberculosis treatment and remained asymptomatic until this presentation. To investigate the new pleural mass, he underwent a video-assisted thoracoscopic surgery, which revealed a 2.2 kg mass in the pleural cavity involving the anterior mediastinum and chest wall and adhered to the visceral pleura. Following conversion to an open thoracotomy, the mass was completely excised, which involved non-anatomical lung resection. Histopathology and immunohistochemistry of the resected tumour were consistent for a desmoid tumour. He was followed up for 9 months with no evidence of tumour recurrence. Predominantly pleural-based desmoid tumour is rare but should be included in the differential diagnosis of spindle cell tumours.