Medline Plus Encyclopedia
Monday, 13 February 2012
Sarcoidosis is an inflammatory granulomatous disease that may affect the thyroid gland either alone or in conjunction
with other organs. In sarcoidosis, clumps of abnormal tissue composed of immune cells (non-caseating granulomas) lodge in various organs. According to lead researcher M. Giovinale at the Catholic University of the Sacred Heart in Rome, sarcoidiosis is associated with pulmonary findings in more than 90 percent of patients. However, extrapulmonary (targeting organs other than the lungs) involvement is common, and all organs can be involved (especially lymph nodes, eyes, joints, central nervous system). Sarcoidosis frequently occurs as a systemic autoimmune disorder affecting multiple organs and tissues. Giovinale also reports than an isolated extrapulmonary disease, such as sarcoidoisis of the thyroid gland with no other organ involvement, is seen in less than 10 percent of patients.
Sarcoidosis of the thyroid gland is considered relatively rare. Similar to other thyroid disorders, thyroid sarcoidosis is most likely to affect affect young and middle-aged females. However both males and females of all ages may be affected. This condition primarily causes hypothyroidism because of the development of fibrosis (scar tissue). However, it may cause a euthyroid (normal thyroid function) form of thyroiditis or multinodular goiter along with thyroid gland enlargement (goiter). In multinodular goiter, patients may experience shortness of breath when lying in a supine position.
On occasion, sarcoidosis of the thyroid gland occurs in conditions of hyperthyroidism, primarily in Graves’ disease and less often in conditions of toxic multinodular goiter (TMG). In TMG toxic refers to the development of hyperthyroidism. When sarcoidosis occurs in patients with hyperthyroidism that's resistant to treatment with I131 ablation or anti-thyroid drugs, an evaluation for sarcoidosis is indicated. In cases where thyroidectomy surgery was used to treat hyperthyroidism that didn't respond well to other treatments, sarcoidosis of the thyroid gland has been reported as an incidental finding in postoperative tissue studies.