Hyung Suk Seo, Presenter: Nothing to Disclose

Ki Hwan Kim, Abstract Co-Author: Nothing to Disclose

Younghen Lee MD, Abstract Co-Author: Nothing to Disclose

Sang-Il Suh, Abstract Co-Author: Nothing to Disclose

Fat-containing thyroid lesions have known to be very rare and only several pathologic reports were published. The purposes of this study were to determine the prevalence of intrathyroid fat lesions on CT imaging, to analyze the CT appearances and the pathology, and to review previous reports systematically.

In 1,205 patients who underwent neck CT scanning for 1 year, 13 patients(M:F=4: 9; mean age 44.6±15.2 years) had intrathyroid fat-containing lesions, a prevalence of 1.2%. Mean size of the intrathyroid fat-containing lesion was 5.7 mm(range: 2.6-10.6 mm). Most of them were nodular-shaped(92%) and homogeneous(92%) with a band connecting to extrathyroid fat(77%) like scoop (Figure). Posterior(85%), medial(85%), and upper (92%) locations of the both thyroid lobes were common. In 4 patients who underwent surgery, a fat-containing nodular hyperplasia, an ectopic thymic tissue with mature fat, and an only mature fat tissue were confirmed. In 40 fat-containing thyroid lesions in 15 previous studies, 11 were diffuse lesions and 29 were focal lesions.

The prevalence of intrathyroid fat-containing lesions was 1.2%. Most of them were nodular and homogeneous with fatty bands in posteromedial location of both upper thyroid lobes. These finding may support the developmental anomaly hypothesis and might prevent unnecessary invasive procedures.

Seo, H, Kim, K, Lee, Y, Suh, S, Intrathyroid Fat-containing Lesions Using CT Imaging with Systemic Literature Review.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13025953.html