INTENSE ACCUMULATION OF TL-201 IN CARCINOID-TUMOR OF THE THYMUS

A case of carcinoid tumor of the thymus is presented in which Tl-201 S PECT demonstrated intense accumulation in the lesion. Conventional che st radiograph and CT scan in a 66-year-old man who had been experienci ng cough and pain at the anterior part of the chest revealed a tumor i n the anterior mediastinum, suggesting a thymoma. The tumor was clearl y delineated in both early and delayed SPECT studies. On the delayed s can, the tumor was more prominently visualized with an extremely high uptake ratio of the lesion compared to the contralateral background; t herefore, the tumor was believed to possess very prolonged Tl-201 rete ntion. The pathological and immunohistochemical examinations confirmed that the area of intense Tl-201 uptake was rich in viable cells.