[Desmoid fibromatosis of the posterior mediastinum].
ABSTRACT Fibromatosis are uncommon connective tissue tumours arising from musculo-aponeurotic tissue and characterised by spindle cell fibroblastic and myofibroblastic proliferation. The exact aetiology is unknown but several factors are considered to be positively correlated with their development and growth (genetic and hormonal factors and trauma). Although they are considered histologically benign they behave aggressively locally and relapse repeatedly after surgical excision. Mediastinal localisation is very rare. We describe a case of de novo fibromatosis of the posterior mediastinum in a 61 year old man with no history of thoracotomy or trauma. Although mediastinal fibromatosis is very uncommon physicians should be aware of this disease in order to ensure appropriate surgical treatment.