Endocrine Abstracts

Introduction: Amyloid goitre is a rare cause of thyroid enlargement, especially as a reason of fast growth. Here we present unusual case of idiopathic AA-amyloidosis as a cause of rapidly growing goitre.

Clinical case: Patient 36-year-old presented with complaints of shortness of breath and deglutitive problems during 2 months. His medical history was notable for nephrotic syndrome due to AA-amyloid nephropathy and chronic hepatitis C that were diagnosed 8 years ago. At that time in order to determine the cause of AA amyloidosis, there were performed extensive laboratory evaluation, the results of which turned out barren of definitive diagnosis. The pathogenic and symptomatic treatment of nephrotic syndrome was prescribed. 3 years later he was diagnosed with terminal stage of chronic kidney disease, and chronic haemodialysis was started. Physical examination revealed considerably enlarged thyroid gland, and ultrasound was performed. The volume of gland was 163 ml, and there were detected three lesions about 2.5 cm in diameter. The results of thyroid ultrasound, which was performed because of screening for hyperparathyroidism 6 months ago, were normal. In order to determine the nature of lesions there was done fine-needle biopsy, the results of which were consistent with macro-microfollicular goiter. The thyroid function was normal (TSH 0.93 mU/l). Since there were objective signs of upper airway obstructive symptoms, there were performed thyroidectomy. Microscopically, the stroma contained deposits of amorphous material characteristic of amyloid. These deposits stained with Congo red and were apple green in colour when examined microscopically under polarised light. Immunohistochemical staining patterns were consistent with AA amyloid. There was extensive fat cell metaplasia in the thyroid interstitium.

Conclusion: The differential diagnosis of rapid thyroid enlargement should include amyloid goitre nevertheless the type of enlargement (in our case it was not typical diffuse manner) and amyloidosis duration if it is present.