[A case of malignant aortico-pulmonary paraganglioma].

A 64-year-old male was admitted to our hospital suffering from dysphagia and dyspnea. The chest X-ray films and chest CT films revealed huge tumor in his upper-anterior mediastinum. The filling defect at lower rim of the left brachiocephalic vein on venography indicated malignant potential of the tumor. There was no abnormal value in blood and urine examinations except CA 19-9 which was 31.8 U/ml. The tumor was resected with bilateral pleura, pericardium and left brachiocephalic vein. Macroscopically the specimen accompanied with a lot of bleeding spots was soft and yellow and has no capsule. The size of tumor was 15 X 13 X 8 cm and its weight was 865 gm. No tumor recurrence was found until present time: two years after surgical therapy followed by adjuvant radiation therapy (60 Gray). Though histological findings of anterior part of the tumor were consisted of "Zellballen" cells and bleedings, the posterior part had cell atypia and invasion into vessels. These cells were slightly positive on Keratin stain and on NSE stain. Typical findings of paraganglioma were also indicated by electron microscopy: those findings were more chief cells, fewer sustentacular cells, abundant mitochondria and few dense-cored granules which are thought to secrete hormonal substances. Judging from these clinical and pathological results, this tumor was diagnosed nonfunctional aortico-pulmonary paraganglioma. Mediastinal paraganglioma is a very rare tumor. There is no report of malignant aortico-pulmonary paraganglioma in Japan after Glenner and Grimelys' study concerning extra-adrenal paraganglion system.