[CT morphology and clinical diagnosis of thoracic space-occupying lesions in patients under 40 years of age].

83 patients with thoracic masses and aged under 40 years, who had been seen in a chest clinic, were examined by CT. They were classified according to their diagnosis and typical CT findings were analysed. Bronchial carcinomas showed predominantly radial extensions and air trapping. Malignant lymphomas and benign tumours usually showed smooth outlines and evidence of some fat content. Malignant mediastinal or neurogenic tumours frequently contained liquid portions and calcification. The CT diagnosis of lymphomas (seven cases), metastases (28 cases) and benign tumours (13 cases) presented no problems in view of the typical appearance and position of the tumours; classification of malignant mediastinal or neurogenic tumours (seven cases) was difficult. Inflammatory masses (14 cases) and bronchial carcinomas (14 cases) showed similar CT appearances.