Amyloid goiter: report of two cases and review of the literature.

OBJECTIVE

To describe two recent cases of amyloid goiter that occurred in two patients with a history of diffuse enlargement of the thyroid gland, progressing over several years' time.

METHODS

We reviewed the medical histories as well as the histologic, immunohistochemical, and electron microscopic findings in these patients.

RESULTS

Assessment of the clinical records of a 59-year-old man and a 64-year-old woman revealed histories that included chronic psoriasiform arthritis and asthma in conjunction with chronic obstructive pneumonia and bronchiectasis. In both cases, total thyroidectomy was performed. On histologic examination of both thyroid glands, the appearance was characterized by moderate to severe distortion of the normal thyroid architecture by amyloid in a perifollicular distribution and focally abundant interfollicular adipose tissue. In both cases, the amyloid stained intensely positive with Congo red, which bleached after treatment with potassium permanganate. Immunohistochemical staining patterns were consistent with AA amyloid, and electron microscopy showed nonbranching 9-nm fibrils consistent with amyloid.

CONCLUSIONS

The diagnosis of amyloid goiter should be suspected in patients with a diffusely enlarging thyroid gland and an appropriate clinical history.