Sindrome mediastinica da mieloblastoma quale manifestazione d'esordio di leucemia mieloide acuta

The authors report a case of acute myeloblastic leukemia which at the onset was characterized by a granuloblastic mediastinal tumor, without the appearance of a blastic population in the peripheral blood. The diagnosis was allowed by the cytological and cytochemical study of the pleural effusion. The autopsy confirmed the invasion of several organs by the myeloid malignant cells.The authors describe the clinical and histopathological characteristics of the disease. They point out that the histogenesis of this case and other similar ones reported in the literature remains obscure. The possibility is suggested that microenvironmental factors may have a critical role in facilitating the in situ proliferation of circulating blast cells with formation of solid tumor masses.