Abstract
A 55-year-old woman, who had been treated for nephrotic syndrome, was referred to our department due to an asymptomatic nodule at the anterior mediastinum. She had a past history of intestinal tuberculosis. The anterior mediastinal nodule was 2 cm in diameter, adhering to the left upper lobe of the lung, as revealed by computed tomography. FDG-PET scan showed a strong accumulation of FDG in the mediastinal nodule (SUVmax: 6.93), and weak accumulation of FDG was also noted in the supraclavicular, mediastinal, and hilar lymph nodes. As a diagnostic and therapeutic procedure, surgical resection using video-assisted thoracic surgery (VATS) was performed, with combined resection of the left upper lobe of the lung. The tumor was filled with pus that was positive for Mycobacterium tuberculosis on by PCR examination. Pathological examination identified epithelioid granuloma with caseous necrosis in the thymic tissue. Although thymic tuberculosis is a rare disease, the possibility of it should be kept in mind when treating a patient with an anterior mediastinal nodule irrespective of the past history of tuberculosis.
