Anterior mediastinal mass due to thoracic splenosis.

To cite: Soraru J, Cardaci G. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014208376 DESCRIPTION An 81-year-old man was investigated for weight loss, fever, deranged liver enzymes and elevated inflammatory markers. CT imaging revealed a lobulated well-defined anterior mediastinal mass (1.7×2.8×3.2 cm) and a further small (1.43×0.59×1.9 cm) subpleural nodule in the left posterior thorax. The possibility of mediastinal neoplasm was raised, with biopsy of the anterior mediastinal mass contemplated. There was a history of blunt abdominal trauma 30 years prior, requiring surgical repair of a ruptured left hemidiaphragm, splenectomy and left nephrectomy. Considering this, a heat denatured red blood cell (RBC) study was performed. Tc-99m labelled autologous RBCs were warmed in a hot water bath to crenate but not lyse the cells, and were reinjected prior to SPECT-CT imaging. As the spleen functions to entrap and remove damaged RBCs, the heat-denatured RBC study is a