Amyloid Goiter as a Manifestation of Primary Systemic Amyloidosis

Abstract

Primary amyloidosis involving the thyroid gland is rare and limited to case reports. We report the case of a previously healthy 47-year-old female presenting with a 1-month history of nausea, vomiting, and diffuse thyroid enlargement. Over the next 3 months, she simultaneously developed renal insufficiency dysphagia and hoarseness of voice. Biopsies from the gastric antrum, duodenum, bone marrow, and kidney were positive for vascular deposition of amyloid. Ultrasound of the thyroid revealed diffuse enlargement of the thyroid gland, which was 32.8 ML in volume, with diffuse hyperechogenicity. Fine needle aspiration (FNA) biopsy was positive for amyloid by Congo red staining, and cytology was negative for malignancy. The patient was treated with dexamethasone 40 mg daily on days 1-4, 9-12, and 17-20 for 3 months. On 3-month follow-up, the patient's nausea and vomiting had resolved and renal insufficiency improved. Ultrasound of the thyroid demonstrated decrease in the size of the goiter to 23.2 ML. Amyloid goiter is seen only in approximately 0.04% of patients with primary systemic amyloidosis. No data is currently available regarding treatment of primary amyloidosis and its effect on the goiter. However, we have evidence demonstrating that successful treatment of amyloidosis decreases thyroid enlargement and improves organ dysfunction.