Amyloid Goiter: Radiological Study in a Case Presenting Hypothyroidism

Abstract

We report herein a case of amyloid goiter associated with rheumatoid arthritis in which hypothyroidism was observed. A 52-year-old housewife who had suffeed from rheumatoid arthritis for 15 years was referred to our hospital because of general fatigue. On admission, a large goiter was observed. Laboratory data showed primary hypothyroidism. Renal biopsy and gastric mucosa biopsy showed amyloid deposition of AA-type. Thyroid biopsy showed massive amyloid involvement. Although the findings of iodine-123 scintigraphy, technetium-99m pertechnetate scintigraphy, computed tomography and magnetic resonance image studies were similar to those for goiter associated with chronic thyroiditis, tallium-201 chloride scintigraphy gave a differing result, demonstrating absent uptake at 3 hours in this case. Replacement therapy with levothyroxine relieved the symptoms. This case was unusual in that amyloid goiter presented clinically as hypothyroidism. Absence of tallium-201 chloride uptake at 3 hours may be a diagnostic specificity for amyloid goiter in differentiating its hypothyroidism from that caused by chronic thyroiditis.

Primary Amyloid Goiter and Review of Imaging Characteristics

“…5 The deposits are usually asymptomatic causing neither goiter or thyroid dysfunction, 2 although the latter has been described. 3, 6…”

“…It is present in longstanding systemic inflammatory disorders, such as rheumatoid arthritis, ankylosing spondylitis and Crohn's disease. 2, 4, 6-8…”