Presentation
Recurrent renal stone disease
Patient Data
![](https://prod-images-static.radiopaedia.org/images/2776399/b3931e69acb158ea3a8e9c7de35c81_big_gallery.jpg)
A chest radiograph was performed prior to percutaneous nephrolithotomy (PCNL).
Right sided mediastinal mass, which demonstrates the hilum overlay sign.
![](https://prod-images-static.radiopaedia.org/images/2776406/c4a291bb464f377f8223514a4f5805_big_gallery.jpg)
A MIBI scan was undertaken to assess for a parathyroid adenoma.
Avid tracer uptake in the mediastinal mass visualized on plain chest radiograph, confirms it represents an ectopic parathyroid adenoma.
Case Discussion
In a small number of cases, recurrent renal stone diseases (nephrolithiasis) is due to an underlying metabolic condition. This includes primary hyperparathyroidism due to a parathyroid adenoma. Rarely these occur in an ectopic location, typically the mediastinum, rather than in the neck.