case_images: PMC4058972_01
case_images: A 4-year-old child with intrathyroidal thymic tissue.. A, B. Transverse (A) and longitudinal (B) scans of gray-scale sonography show an ill-defined nodule (white arrow) with multiple hyperechoic foci in the mid-portion of the right thyroid. C. Color Doppler sonography shows no flow within the nodule. D. A cytological smear slide shows Hassall's corpuscles (black arrow) with a background of small lymphocytes (H&E, x400).
case_images: usg-33-1-71-12f1.jpg
case_images: PMC4058972_01_usg-33-1-71-12f1.jpg
case_images: f1-usg-33-1-71-12
case_images: The US findings of the thyroid nodule were an ill-defined margin and multiple hyperechoic foci similar to microcalcifications (Fig. 1A, B). Color Doppler sonography showed scanty blood flow within the nodule (Fig. 1C). A cytological investigation revealed Hassall's corpuscles with a background of small lymphocytes (Fig. 1D) and confirmed the diagnosis of ectopic thymic tissue within the thyroid gland.