Amyloid goiter in Familial Mediterranean Fever (FMF): a clinicopathologic study of 10 cases

FMF Amyloidosis is an important etiological factor of end stage renal disease (ESRD) in Mediterranean Countries. Apart from major target organs as cardiovascular, respiratory and gastrointestinal system, endocrine organs can also be involved. We planned to investigate the thyroid involvement in our amyloidosis group. The aim of this study was to determine clinical characteristics of amyloid goiter in FMF patients and the abnormalities of thyroid function, as well as to identify pathologic characteristics. Twenty-two hemodialysis patients (mean age 34.1 +/- 14 years, range 17-68) whose ESRD secondary to FMF amyloidosis were evaluated with physical examination, serum levels of thyroid hormones, ultrasound examination of thyroid glands, thyroid syntigraphic studies. Goiter was found in 10 patients (4 male, 6 female) having enlarged neck mass (mean age 35 +/- 14 years, range 23-64). The serum levels of thyroid hormones and TSH were normal in 4 patients. Other four cases had euthyroid sick syndrome. Only one patient developed tender enlarged neck mass with subacute thyroiditis symptoms and one had primary hyperthyroidism. Ultrasound examination showed; hypoecoic nodules in 6 patients diffuse multinodular enlargement in 4 patients. Thyroid syntigraphic studies revealed hypoactive nodules in 7 patients and hyperactive nodules in 3 patients. After the laboratory tests were completed, in 10 patients diagnosis were made with fine needle aspiration biopsy. Of 10 patients 5 underwent subtotal thyroidectomy. Immunohistochemical evaluation demonstrated the presence of amyloid AA immunoreactivity in all cases. In conclusion fine needle aspiration from the thyroid when enlarged is useful in the diagnosis of suspected amyloidosis, especially since it is a safe, easily performed procedure. With the help of amyloid goiter diagnosis the patient's prognosis on hemodialysis and with renal transplantation can be predicted. Amyloid goiter must be searched in hemodialysis patients especially in Mediterranean Countries.