A 4-year-old HIV-uninfected girl was referred  to the paediatric pulmonology clinic at Chris  Hani Baragwanath Academic Hospital, South  Africa (SA), with a 2-year history of chronic  cough and poor weight gain. She had been  treated with repeated courses of antibiotics  for respiratory tract infections, and had also  been started on tuberculosis (TB) therapy  based on the chronic cough and abnormal  findings on chest radiographs. 
 At presentation, she was stunted, had  digital clubbing, and had dullness to  percussion on the right side of the chest  with reduced breath sounds. Her white  cell count was raised (20.7 x 109 /L) with  predominant lymphocytes (80.9%). The  frontal chest radiograph showed a dense  homogeneous opacification in the right  middle and lower zones, and the left middle  zone (Fig. 1). The lateral chest radiograph  showed that the opacification was from the  anterior mediastinum. Bronchoscopy showed  a patent right upper lobe bronchus, but the  right bronchus intermedius was completely  occluded as a result of external compression. 
 The left upper and lower lobes were normal  in structure with patent bronchi. A chest  computed tomography (CT) scan (Fig. 2)  showed an anterior soft-tissue hypodense  mass on the right with herniation across the  midline to the left hemithorax that displaced  surrounding structures but was not encasing  them. Histological examination of a Tru-Cut biopsy specimen showed benign thymic  parenchyma with no evidence of neoplastic  infiltration. 
 Sternotomy was performed and the entire  mass was resected. The tumour was initially  removed as a well-encapsulated bilobar mass,  but the mass extended posteriorly into the right  thorax and required some piecemeal resection  (Fig. 3). Two large specimens were analysed,  weighing 610 g and 360 g and measuring  170 x 100 x 30 mm and 120 x 60 x 20 mm,  respectively. Microscopy revealed thymic  parenchymal tissue mixed with mature adipose  tissue, and no features of cytological atypia.  Numerous Hassall's corpuscles were also seen.  The final histopathology report confirmed that  the tumour was a thymolipoma. There were no  intra- or postoperative complications, and the  patient was discharged.