Is the Thymus Important in Adults?

Infants born without a thymus have severe combined immunodeficiency, and children who undergo thymectomy have long-lasting lymphopenia. However, in adults, the thymus involutes and sometimes is removed during thyroid or cardiac surgery with little concern for adverse immunologic effects.

In a retrospective analysis from Massachusetts General Hospital, 1146 patients who underwent thymectomy were matched to control patients who underwent cardiothoracic procedures with thymus sparing. In the thymectomy group, 511 had cancerous thymomas, and 370 had “suspected thymic masses;” additionally, 265 underwent thymectomy during cardiac surgery, thyroid/parathyroid surgery, or for indeterminate reasons. At 5 years, thymectomy patients were significantly…