A Case of Thyroid Amyloidosis Misrecognized as Subacute Thyroiditis

Amyloid deposition in the thyroid is found in about 30-80% of the patients with primary or secondary amyloidosis. In a few patients with amyloidosis, the thyroid is enlarged and so called amyloid goiter occurs. The thyroid function usually remains normal, but occasionally hypothyroidism or thyrotoxicosis occurs in patients with thyroid amyloidosis. We have experienced one case of thyroid amyloidosis due to bronchiectasis and the patient developed painful goiter and transient thyrotoxicosis resembling subacute thyroiditis. Biopsies from the gastric antrum, duodenum, colon, kidney and thyroid were positive for deposition of amyloid. When patients have signs and symptoms of subacute thyroiditis, but they develop an unusual course, then the diagnosis of thyroid amyloidosis should be considered.