Abstract
A 63-year-old male complained of left anterior and posterior chest pains with fever (38°C) in early August 2008. His symptoms persisted, and he was referred to our hospital with suspected pleuritis. Blood tests showed inflammation, and chest CT with contrast enhancement revealed a 3×8×10-cm heterogeneous lesion in the anterior mediastinum with an increased density of surrounding adipose tissue and bilateral pleural effusion. A second CT study after a two-week follow-up showed reduced inflammation, allowing the identification of two separate lesions in the anterior mediastinum. Based on the results of FDG-PET and MRI, the right-sided lesion was thought to be a thymoma (Masaoka stage III), and the left-sided lesion thymic hyperplasia. Trans-sternal radical thymectomy was performed. The pathological findings showed a thymoma (Masaoka stage II, WHO Type B2) surrounded by multiple cysts containing yellow atheromatous material, leading to the diagnosis of multilocular thymic cysts with thymoma. One-year postoperative follow-up CT showed no recurrence.
