CT findings of the mediastinal tumors -excluding mediastinal granuloma and primary carcinoma-

Computerized Tomography can make accurate diagnosis in most of the mediastinal tumors and cysts by assessing their location, shape and internal architecture. Authors analysed and present CT findings of 89 surgically proven mediastinal tumors and cysts that were studied and treated in Seoul National University Hospital during recent 5 years. The results are as follows; 1. The most common tumor was teratoma (25 cases). Neurogenic tumor (20 cases), thymic tumor or cyst (16 cases), lymphoma (7 cases), bronchogenic cyst (6 cases), intrathoracic goiter (6 cases), pericardial cyst (3 cases) and cystic hygroma (2 cases) were next in order of frequency. 2. The most constant findings of teratoma was thick walled cystic area (100%), while pathognomonic fat and calcified density were seen only in 52% and 48% of cases, respectively. 22 cases were located in anterior mediastinum, 2 cases were in posterior mediastinum and a case is in middle mediastinum. 3. There were 20 cases of neurogenic tumor consisting of 6 neurilemmomas, 7 ganglioneuromas, 4 neurofibromas, 1 ganglioneuroblastoma, 1 neuroblastoma and 1 malignant schwannoma. Most of them were located in posterior mediastinum with exception of 2 neurilemmomas arising from left vagus nerve and left recurrent laryngeal nerve in middle mediastinum. Cystic change was seen in 2 cases of neurilemmoma and in a case of ganglioneuroma. Calcification was seen in 3 cases, of neuroblastoma, a neurilemmoma, and a ganglioneuroma. 4. There were 11 cases of thymoma showing homogeneous solid mass with speckeld calcification in 4 cases and irregular cystic change in 3 cases. 2 cases were invasive thymoma and myasthenia gravis was present in 4 cases. A cases of thymolipoma and a case of thymic cyst were included. 5. Lymphoma (2 Hodgkin's and 4 non-Hodgkin's) appeared as lobulated, matted mass in anterior mediastinum especially in prevascular area expanding bilaterally