Endocrine Abstracts

Introduction: Amyloidosis is a disease characterized by the accumulation of an amorphous proteinaceous material, known as amyloid, in various organs and tissues of the body. Amyloid goiter is a remarkably rare pathologic condition due to thyroid massive amyloid infiltration of amyloid light chain (primary) or amyloid A (secondary amyloidosis) proteins.

Case: 54 year-old male, with known history of chronic tophaceous gout medicated with anakinra and prednisolone, obesity (BMI 36.0 Kg/m2), obstructive sleep apnea, heart failure with preserved ejection fraction and an enlarged multinodular goiter. Relevant thyroid nodules were found in the right lobe (4.5 cm, TIRADS 4) and in the left lobe (3.7 cm, TIRADS 2 and 2.6 cm, TIRADS 2). Fine needle aspiration cytology to the TIRADS-4 lesion was non-diagnostic (Bethesda I). Sometime later compliants of cervical compressive symptoms such as dysphagia were found. The ultrasound revealed an overall enlargement of the thyroid gland and its nodules with significant tracheal deviation. Thyroid function tests revealed a TSH 0.96 μUI/ml (RR: 0.30 - 3.18) and a T4L 1.57 ng/dl (RR: 1.01 - 1.65) with negative anti-thyroid peroxidase (TPO) and anti-thyroglobulin (TG) antibodies. A total thyroidectomy was performed. The thyroid weighed 125g and consisted of amyloid lesions associated with diffuse lipomatosis and multiple focal and bilateral papillary microcarcinomas (dominant with 2mm). Proper search for systemic amyloidosis was performed without any discovery. At the last follow-up, he had an excellent biochemical response with undetected Tg level and no evidence of amyloid recurrence.

Conclusions: Deposition of amyloid in the thyroid gland is a rare condition. In patients with a rapid enlargement of the goiter and a history of chronic inflammatory diseases, clinicians should suspect of amyloid involvement. This excessive growth can cause compression of the surrounding structures and warrant a total thyroidectomy. Papillary thyroid carcinoma has been rarely associated to amyloid goiter.