Benign Lesions That Mimic Thyroid Malignancy on Ultrasound Dong Wook Kim, MD  Canadian Association of Radiologists Journal  Volume 66, Issue 1, Pages 79-85 (February 2015) DOI: 10.1016/j.carj.2014.01.004 Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 1 (A) A longitudinal grey-scale sonogram, showing an ovoid nodule with marked hypoechogenicity, ovoid shape, and microlobulated margin in the left thyroid (9.6 × 14.3 × 17.6 mm) (arrows) in a 53-year-old woman with underlying diffuse thyroid disease. Ultrasound (US) guided fine-needle aspiration and US-guided core needle biopsy for this nodule were consecutively performed to rule out thyroid lymphoma, and it was histopathologically confirmed to be chronic lymphocytic thyroiditis. (B) On follow-up US 6 months later, the nodule shows a marked decrease in size (4.3 × 5.8 × 6.5 mm) (arrows). Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 2 Transverse (A) and longitudinal (B), grey-scale sonograms in a 51-year-old woman, showing a suspicious nodule with marked hypoechogenicity and spiculated margin in the right thyroid (arrows in A and B). This nodular lesion revealed cytologic findings of subacute thyroiditis in ultrasound-guided fine-needle aspiration, and it was finally diagnosed as subacute thyroiditis with a nodular configuration. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 3 A longitudinal, grey-scale sonogram in a 53-year-old woman, showing a suspicious small nodule in the right lower thyroid (2.8 × 3.0 × 4.1 mm) (arrow) (A), but a longitudinal, colour-Doppler sonogram shows discrete thyroid vein (arrow) (B), and it was confirmed as a pseudolesion due to thyroidal vein. A transverse grey-scale sonogram in a 43-year-old man, showing a hypoechoic solid nodule with a taller-than-wide shape in the right thyroid (5.2 × 5.9 mm) (arrows) (C), but it is not observed on different sonic windows (arrow) (D). This nodule was finally diagnosed to be a pseudolesion due to a dense, muscular fascia or thyroid capsule. A transverse (E) and longitudinal (F), grey-scale sonograms in a 53-year-old man, showing a hypoechoic solid nodule with taller-than-wide shape in the left upper thyroid (3.4 × 3.6 × 4.2 mm) (arrows in E, F), and it was confirmed as papillary thyroid carcinoma after thyroid surgery. This figure is available in colour online at http://carjonline.org/. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 4 A longitudinal grey-scale sonogram (A) in a 40-year-old man, showing an ovoid, hypoechoic solid nodule with intranodular linear echogenicities in the left thyroid (3.5 × 8.1 × 9.2 mm) (arrows). In a nonenhanced axial computed tomographic image (B), the same lesion (arrow), showing the same attenuation of the subcutaneous fat, and it was finally diagnosed as an intraglandular fat. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 5 A longitudinal grey-scale sonogram (A) in a 50-year-old woman, showing a predominantly cystic thyroid nodule in the left thyroid (12.7 × 14.9 × 20.7 mm) (arrows). After 6 months, a longitudinal grey-scale sonogram (B), showing an ovoid solid nodule with marked hypoechogenicity in the right thyroid (5.3 × 5.5 × 10.2 mm) (arrows). After 10 months, a longitudinal, grey-scale sonogram (C), showing a marked decrease in size (2.6 × 3.5 × 8.8 mm) (arrows), and thus it can be finally diagnosed as a benign fibrotic nodule after spontaneous collapse of a predominantly cystic thyroid nodule. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 6 A transverse grey-scale sonogram (A) in a 20-year-old woman, showing a partially cystic thyroid nodule in the right thyroid (15.0 × 20.8 × 27.3 mm) (arrows). This nodule showed benign cytology in ultrasound (US) guided fine-needle aspiration (US-FNA) and then ethanol ablation for this nodule was performed. Twelve months after ethanol ablation, a transverse grey-scale sonogram (B), showing a suspicious solid nodule with marked hypoechogenicity and spiculated margin (5.1 × 5.3 × 7.7 mm) (arrows). Repeated US-FNA for this nodule was performed because of a suspicious US feature but revealed no malignant cytology. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 7 A benign fibrotic nodule after ethanol ablation of a benign solid thyroid nodule in a 32-year-old woman. A longitudinal, grey-scale sonogram (A), showing a predominantly solid thyroid nodule in the right thyroid (13.1 × 17.9 × 25.8 mm) (arrows), and it revealed benign cytology in ultrasound (US) guided fine-needle aspiration. Six months (B) and 12 months (C) after the second session of ethanol ablation, longitudinal, grey-scale sonograms, showing suspicious US features, but a interval decrease in size (7.6 × 9.1 × 12.5 mm and 5.4 × 5.6 × 7.2 mm, respectively) (arrows in B, C). Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 8 A parathyroid adenoma and an exophytic thyroid malignancy. A transverse (A) and longitudinal (B) grey-scale sonograms in a 35-year-old man, showing a solid nodule with marked hypoechogenicity and round shape in the left perithyroidal area (7.7 × 9.3 × 9.6 mm) (arrows in A, B), and it was confirmed as parathyroid adenoma after surgery. Transverse (C) and longitudinal (D) grey-scale sonograms in a 54-year-old woman, showing a solid nodule with hypoechogenicity in the left perithyroidal area (6.3 × 7.8 × 12.2 mm) (arrows in C, D), and it was confirmed as papillary thyroid carcinoma after surgery. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 9 An esophageal diverticulum and an exophytic thyroid nodule. A transverse grey-scale sonogram (A) in a 55-year-old woman, showing a suspicious solid nodule with microcalcifications and exophytic configuration in the left thyroid (8.7 × 13.9 × 16.5 mm) (arrows). A transverse grey-scale sonogram (B), showing a discrete connection (arrows) between this nodular lesion and esophageal lumen in the same patient. A transverse grey-scale sonogram (C) in a 64-year-old woman, showing a solid, exophytic thyroid nodule in the left thyroid (14.0 × 14.3 × 15.0 mm) (arrows), and it was confirmed to be a nodular hyperplasia with fibrocalcified degeneration in histopathology after thyroid surgery because of coexistent thyroid malignancy. Canadian Association of Radiologists Journal 2015 66, 79-85DOI: (10.1016/j.carj.2014.01.004) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions