A CASE OF GIANT CELL TUMOR OF BONE ARISED IN THE FOURTH RIB PRESENTING WITH A POSTERIOR MEDIASTINAL TUMOR SHADOW

We experienced a rare case of giant cell tumor of bone arising in the 4th rib which was first diagnosed by operation under a preoperative diagnosis of posterior mediastinal tumor. A 35-year-old woman was pointed out having an abnormal shadow on a chest X-ray film at elsewhere and referred to the hospital. Chest X-ray examination on admission revealed a tumor shadow 12.0cm in diameter in the upper lung field to posterior mediastinum region. Based on chest CT and MRI findings the patient was diagnosed as having a posterior mediastinal tumor and operated on in October 1991. It was found that the tumor had no relation to the mediastinum and strongly adhered to the chest wall and lung, a tumor arising in the lung being suspected. Excision of the tumor as well as right upper lobectomy of the lung and partial resection of the 4th lib was carried out. Histopathologically it was giant cell tumor of bone arising in the 4th rib.