Mediastinal leiomyosarcoma concurrent with intra-aortic thrombosis.

We report a case of a large intra-aortic thrombosis in an 83-year-old woman concurrent with metastatic mediastinal leiomyosarcoma. Imaging studies incidentally detected a mediastinal malignant tumour metastasising to bilateral adrenals and an extensive intra-aortic mass that was suspected to be intra-aortic thrombosis. One month later massive embolism developed in the lower limb and her condition deteriorated rapidly resulting in death. Autopsy revealed diffused proliferation of highly pleomorphic atypical cells accompanied by necrosis in the mediastinum tumours and bilateral adrenal glands. Leiomyosarcoma metastasising to bilateral adrenals was confirmed by the results of immunostaining. The intra-aortic mass suggested that the fragmented thrombus might be the cause of a sudden lower-limb embolism. Microscopic examination showed that the mass lesion in the aortic arch was composed of a blood clot containing neutrophils. We report this case because leiomyosarcoma arising from the mediastinum and, especially, associated with an extraordinarily large intra-aortic thrombosis is very rare.