A mass in the posterior mediastinum; extramedullary haemopoietic tissue.

Extramedullary haematopoiesis is a very rare cause of a posterior mediastinal tumour and may be clinically confused with many other mediastinal tumours; benign or malignant. Extramedullary haematopoiesis is a really rare cause of haemothorax and usually it is diagnosed incidentally. Extramedullary masses complicating thalassemias, apart from the known complications, may also bleed and produce acute manifestations like dyspnoea and fatigue. Pathologically, the masses are soft, deep red, and resemble spleen tissue on the cut surface. Histologically, they are formed of hematopoietic tissue mixed with adipose elements. The mass is extremely vascular and contains some fibrous tissue. This particular structure renders the mass prone to haemorrhage. We report a case of posterior mediastinal extramedullary haematopoietic mass in a 56-year-old man who presented with non-specific symptomatology and a paravertebral mass on chest X-ray and in the chest computed tomography. A percutaneous biopsy approach could be technically difficult due to the special location of the mass. Video assisted thoracic surgery (VATS), is a minimal invasive and alternative way of diagnosis, biopsy and treatment of these cases. Diagnosis was achieved in our patient by mini thoracotomy and open biopsy in order to prevent bleeding or neurological damage.