ABSTRACT
<p><b>OBJECTIVE</b>To study immunohistochemical expression of GADD153 and assess its usefulness as markers in the differential diagnoses in follicular tumors of the thyroid.</p><p><b>METHODS</b>Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissue of 34 cases of follicular thyroid adenomas (FTA), 46 cases of follicular thyroid carcinomas (FTC), 29 cases of follicular variant papillary carcinomas (FVPC).</p><p><b>RESULTS</b>(1) GADD153 was expressed in cell nucleus with positive or strong positive expression in FTC, and no or weak expression in FTA and FVPC. The positive expressions of GADD153 were present in 38 of 46(82.6%) in FTC, 11 of 34(32.4%) in FTA and three of 29(10.3%) in FVPC, the positive expression rate in FTC was obviously higher than that in FTA and in FVPC, the differences were statistically significant (χ² = 20.80 and 37.48; P < 0.01). (2) CK19, Galectin-3 (Gal-3) and HBME-1 were all expressed in the cytoplasm, the positive expressions of CK19, Gal-3 and HBME-1 were present in 54.3% (25/46), 67.4% (31/46) and 58.7% (27/46) in FTC; 50.0% (17/34), 29.4% (10/34) and 32.4% (11/34) in FTA; 100% (29/29), 93.1% (27/29) and 89.7% (26/29) in FVPC, the differences were statistically significant as well (χ² = 21.20 and 8.22; P < 0.01). (3) According to the expressions of CK19, Gal-3, HBME-1 and GADD153, we divided the results into low expression group (0 or 1+) and high expression group (2+ or 3+), the sensitivity and the specificity were calculated. in FTA, the sensitivity were 26.5%, 8.8%, 2.9% and 11.8%; the specificity were 50.7%, 52.0%, 54.7% and 58.7%. in FTC, the sensitivity were 19.6%, 26.1%, 23.9% and 65.2%; the specificity were 41.3%, 57.1%, 62.0% and 92.1%. in FVPC, the sensitivity were 96.6%, 82.8%, 79.3% and 3.4%; the specificity were 77.5%, 81.3%, 85.0% and 57.5%.</p><p><b>CONCLUSIONS</b>The sensitivity and the specificity of GADD153 expression are well for diagnosing FTC, and CK19, Gal-3, HBME-1 are well for FVPC. The four markers when used in combination, are better to identify the follicular tumors of the thyroid.</p>