THYROID-DYSFUNCTION IN PATIENTS WITH AMYLOID GOITER

OBJECTIVES Widespread amyloid deposition in the thyroid gland causes d iffuse, clinically apparent enlargement of the thyroid (amyloid goitre : AG), The aim of this study was to clarify the abnormalities of thyro id function in patients with AG, DESIGN Thirty patients with secondary amyloidosis were retrospectively analysed, Their thyroid status was e valuated using the results of routine thyroid function tests and measu rement of thyroid autoantibodies. Thyroid needle biopsy was carried ou t to identify amyloid deposition in the thyroid gland, RESULTS Thyroid enlargement was observed in 19 (63%) of 30 patients with amyloidosis. Eleven of these 19 patients had a thyroid biopsy and/or autopsy and a myloid deposition was histologically revealed in 10 (defined as AG) of these 11 patients, Nine of 10 patients (90%) with AG had abnormalitie s of thyroid function, including five patients with hypothyroidism, on e with hyperthyroidism, one with transient hypothyroidism, and two wit h low T3 syndrome, Five had thyroid autoantibodies. The patient with h yperthyroidism had positive thyroid stimulating antibody (TSAb) and hi gh I-131 thyroidal uptake, suggesting the coexistence of Graves' disea se. Another patient suffered from thyroidal pain and showed transient hypothyroidism, high level of serum thyroglobulin and low thyroidal up take of I-123, the clinical course being compatible with subacute thyr oiditis, CONCLUSIONS The incidence of thyroid abnormalities accompanie d by AG, although asymptomatic, is unexpectedly high, Thyroid function should therefore be regularly assessed during follow-up of patients w ith systemic amyloidosis.