Endocrine Abstracts

Background: Amyloidosis is an important etiological factor of end stage renal disease. Apart from major target organs as cardiovascular, respiratory and gastrointestinal system, endocrine organs can also be involved. Amyloid goitre was described for the first time by Beckmann in 1858. Approximately 200 cases of amyloid goiter have been reported in English literature.

Case presentation: The patient is a 67-year-old woman. The patient referred in 1989 the presence of a thyroid nodule of the left lobe investigated by scintigraphy and fine needle aspiration cytology (compatible with goitre). 3 months prior to her admission, the patient noticed a progressive enlargement in the anterior region of the neck associated with dyspnea dysphagia and hoarsness. Preoperative ultrasound showed an enlargement thyroid with US stimated gland volume of 105 mL, a 3 cm nodule in the left lobe and micronodularity in the right lobe. Chest X-ray revealed a deviation of the trachea. She was biochemically euthyroid. Because of the obstructive symptoms the patient underwent thyroidectomy. Histologic examination confirmed diffuse amyloid deposition surrounding thyroid follicles. Moreover, a nodular pattern of amyloid deposition was seen resulting in compression and distortion of the follicular architecture. Confirmation of amyloid was made by the presence of congophilia and apple-green birefringence under polarized-light microscopy. No Immunoreactivity was seen with calcitonin or thyroglobulin. One year after primary surgery, the patient was admitted to the Nephrology Department because of acute renal failure.

Conclusion: Amyloid goitre as the initial manifestation of systemic amyloidosis is an exceedingly rare condition associated with clinically apparent enlargement of the thyroid gland due to massive amyloid infiltration. We describe the clinical and pathological features of amyloid goitre and the difficulties in making a pre-operative diagnosis. In this case, amyloid goitre had no significant influence on thyroid function even when extensive parenchyma replacement was present. A plan of management for this rare thyroid condition must be suggested.