This patient was a 35 y/o male who presented with shortness of breath and bilateral pleural effusions. Pleural fluid cytology was benign. Imaging studies revealed a mediastinal mass which was excised. Sections showed dense fibrosis, a polymorphic inflammatory infiltrate with abundance of plasma cells, and dystrophic calcification. Cultures were negative for fungal organisms and mycobacteria. The findings are consistent with idiopathic sclerosing mediastinitis.