An autopsy case of malignant fibrous histiocytoma of the mediastinum, presenting multiple metastases to the small intestine and to the brain--a rare case report with a review of the literature.

An autopsy case of malignant fibrous histiocytoma (MFH) of the mediastinum in a 25-year-old Japanese man is described. He initially complained of general fatigue and intermittent tarry stool, and was radiographically revealed to have a huge mass within the mediastinum as well as multiple nodules within the abdominal cavity, respectively. The mediastinal tumor could not be resected because of direct tumor invasion into surrounding tissues. Within the abdominal cavity, three distinct tumor nodules were discovered in the jejunum, which could be resected surgically. Histopathologically, the components of both lesions were very similar, and the present case was interpreted as multiple metastases of mediastinal MFH to the intestinal wall. In spite of various kinds of treatment, the mediastinal tumor rapidly enlarged, causing SVC syndrome. Brain CT findings suggested multiple metastases which were considered to be the cause of death. Autopsy confirmed that the main tumor nodule was located within the mediastinum, with brain metastases. The present case of mediastinal MFH is considered to be the youngest case as well as the first case presenting intestinal metastases.