Clinical course of acute hemorrhagic infarction of a thyroid nodule

A 27-year-old woman patient with acute hemorrhagic infarction of a thyroid nodule had experienced abrupt painful swelling of the thyroid gland soon after being involved in an automobile accident. We diagnosed her thyroid mass, based on clinical symptoms and laboratory findings, as acute hemorrhagic infarction of a thyroid nodule. The mass diameter gradually decreased from 4.4 cm to 1.9 cm over the following 12 months but did not change thereafter. The serum thyroglobulin level rapidly decreased from 312.4 ng/ml to 14.2 ng/ml during the first 3 months and presented no change during the next 21 months. Fine-needle aspiration biopsy was repeated during the 24th month, when preexistence of a benign neoplasm had become clear. The clinical course of acute hemorrhagic infarction of the thyroid nodule was made apparent by ultrasonography, which readily identified the thyroid mass and accurately measured its dimensions at any time.