Retrosternal and pleural "bridging" fibrosis mimicking malignancy in a patient exposed to asbestos

Mediastinal fibrosis is a rare, benign disorder characterised by proliferation of fibrous tissue within the mediastinum. It can present as diffuse mediastinal infiltration or, more frequently, as a localised soft tissue mass, usually in the right paratracheal or subcarinal areas. 18-fluorodeoxyglucose (18-FDG) positron emission tomography (PET) imaging has only been reported in a few case reports with variable aspects. Herein, we present an unusual pattern of mediastinal fibrosis, presenting as a thick retrosternal mass contiguous with pleural thickening. 18-FDG PET showed intensely increased uptake in the mass. Both the location of fibrosis and PET imaging were confusing with malignancy. Histopathological proof of benign fibrosis was obtained by surgery. The patient had been exposed to asbestos and the possible relationship of this particular pattern of fibrosis with asbestos exposure will be discussed.