Amyloid goiter.

BACKGROUND AND AIM: Amyloidosis refers to a variety of conditions in which amyloid proteins are abnormally deposited in organs and/or tissues. Amyloidosis is a rare occurrence in thyroid gland.

METHODS: A systematic review of the published data on amyloid goiter was carried out by searching Medline and other online databases (such as Scopus and Endnote) for the period from 1951 to March 2008. A total of 127 publications (case series, single case reports and reviews) was found, of which 31 were case series published from February 1995 to March 2008. Six articles have been considered for our review because they regard amyloid goiter as a manifestation of both primary and secondary amyloidosis (a total of 30 cases have been analyzed). Exclusion criterion was the presence of primary thyroid cancer.

RESULTS: The preoperative diagnosis of amyloid goiter should be considered in patients with known systemic amyloidosis or with a long-standing predisposing disease who present a rapidly growing thyroid volume in association with a euthyroid state. Fine-needle aspiration biopsy can be performed to exclude primary malignant lesions of thyroid gland and immunohistochemical studies can identify and characterize the amyloid deposits.

CONCLUSION: Amyloid goiter has to be suspected in all patients with a progressive, rapidly growing, bilateral thyroid enlargement and a concomitant history of chronic inflammatory processes. Moreover, this should be suspected in patients who are known to have disease predisposing to amyloid deposition.