Journal of the Medical Association of Thailand Vol 93, No 4:APRIL 2010 0125-2208 93 4 2010 Apr Helpful CT Findings for Giving Specific Diagnosis of Anterior Mediastinal Tumors 489 EN Kanyarat Totanarungroj Chatchamanan Watcharaporn Nisa Muangman Original Article To characterize the CT features of common anterior mediastinal tumors and evaluate CT findings that may helpin suggesting specific diagnosis among these tumors. Fifty chest CT studies with pathological diagnosis of thymoma (n = 28), mediastinal germ cell tumor(n = 14) and lymphoma (n = 8) were retrospectively reviewed by two radiologists who were blind to the pathological results.The CT findings of fat, cyst and calcification within the lesion, contrast enhancement, associated intrathoracic findings suchas mediastinal invasion and lymph node enlargement were evaluated. Fat density within the mass was present in 57.1% with germ cell tumor, which was significantly higher than otheranterior mediastinal tumors (p < 0.05). The presence of associated mediastinal lymphadenopathy was significantly found inlymphoma (75.0%) compared to other tumors (p < 0.05). The other CT findings showed no significant difference among thesediseases (p > 0.05). The CT findings that help in giving specific diagnosis of anterior mediastinal tumors which are fat attenuationand associated mediastinal lymphadenopathy. The presence of fat attenuation is highly suggestive of germ cell tumor andanterior mediastinal mass associated with mediastinal lymphadenopathy elsewhere is indicative of lymphoma. Anterior mediastinal tumor Computed tomography Germ cell tumor Lymphoma Thymoma