Nuket Eliyatkın1, Güldidar Basmacı2, Ahmet Aykas3, Evrim Yalçın4

Keywords: Thyroid, amyloid, familial mediterranean fever

Abstract

Amyloidosis is a disease of unknown etiology characterized with the accumulation of an amorphous, proteinaceous material in various organs and tissues of the body. Amyloid goitre is a rare entity defined by the presence of amyloid within the thyroid gland and reveals itself as markedly enlarged thyroid gland clinically. Amyloid goitre occurs in association with both primary and secondary systemic amyloidosis, more commonly in the latter. In addition, amyloid accumulation in thyroid gland may also be seen in cases of medullary thyroid carcinoma. In this report we described, diffuse and dense accumulation of amyloid within the thyroid gland in three cases with the previous history of Familial Mediterranean Fever. Determination of diffuse enlargement at the thyroid gland during routine physical examination lead the patients to thyroid ultrasonography and multiple nodules wereestablished.Thefirstpatienthadsubtotalthyroidectomy. Dense extracellular amorphous eosinophilic material infiltration and loss of normal follicular pattern within thyroid parenchyma, thinning of follicular epithelium and atrophy were determined in H/E sections. The other two cases had subtotal thyroidectomy too. The cut surface of thyroid gland was yellow in colour and showed pink, amorphous collection within interfollicular and perifollicular spaces which compress the follicles, diffuse fat cell metaplasia mixed wirh ordinary parenchyma within the interstitium, microscopically. The amorphous material accumulated in all three cases stained pink-orange with Congo-red diffusely and showed apple green birefringence under polarized microscope histochemically. This material stained positively with amyloid AA (Clone mc1, Dako) immunohistochemically. All three cases were diagnosed as “amyloid goitre”.