Painless thyroiditis associated with severe inflammatory reactions in amyloid goiter: a case report

We report the case of a 64-year-old woman with rheumatoid arthritis (RA) associated with high grade fever, malaise, and painless swelling of thyroid gland. Laboratory findings showed severe systemic inflammatory reactions, including increases in various cytokines such as IL-6. Gallium-67 citrate imaging revealed intense uptake in the painlessly enlarged thyroid gland. Histologically, biopsied specimens of thyroid showed diffuse amyloid infiltrations, which included amyloid A (AA) protein. Biopsies of rectum and stomach revealed similar amyloid depositions, indicating that the amyloid had a secondary origin, potentially due to RA. All clinical symptoms were relieved by intravenous pulsatile administration of methylprednisolone followed by oral prednisone, resulting in prolonged hypothyroid status. To our knowledge, this is the first case report in Japan describing painless thyroiditis with severe inflammatory reactions in amyloid goiter.