Hypothyroid Hashimoto's thyroiditis with scintigraphic and color flow Doppler sonography features mimicking a hot nodule

Abstract

We report a 59-year-old woman who had Hashimoto's thyroiditis (HT) with hypothyroidism. A solid hypervascularized nodule in the right lobe was detected by color flow doppler sonography (CFDS). Thyroid 99mTc pertechnetate scintigraphy revealed a hot area in the right lobe. After three months, thyroid function tests also revealed hypothyroidism and 131I scintigraphy was similar to the previous scintigraphy. No nodular or hypervascularized lesion in the right lobe could be identified at the sixth month of L-T4 substitution therapy. In conclusion, HT may present as a single hot nodule and hypothyroidism. Imaging findings of HT should be carefully evaluated for the precise diagnosis. © 2009 The Japanese Society of Internal Medicine.