Table 1. Baseline Characteristics According to Cytological Diagnosis.
| FLT (n=55) | AH (n=59) | PTC (n=100) | p value | |
|---|---|---|---|---|
| Clinical and biochemical characteristics | ||||
| Age (yrs) | 54.1±11.3 | 54.4±11.5 | 52.5±11.4 | 0.500 |
| Sex (male:female) | 4:51 | 3:56 | 8:92 | 0.782 |
| Current medications (%)§ | 4 (7.3)* | 2 (3.4) | 1 (1.0) | 0.110 |
| T3 (ng/dL) | 151.4±42.8 | 143.6±26.8 | 150.2±34.2 | 0.485 |
| FreeT4 (ng/dL) | 1.3±1.1 | 1.4±1.3 | 1.55±1.44 | 0.510 |
| TSH (µIU/mL) | 5.5±10.5* | 1.8±1.3 | 1.89±1.31 | <0.001 |
| Tg-Ab positive (%) | 33 (63.5)‡ | 7 (12.3) | 16 (16.0) | <0.001 |
| TPO-Ab positive (%) | 28 (53.8)‡ | 6 (10.7) | 22 (22.0) | <0.001 |
| Largest nodule diameter (mm) | 7.5±4.7 | 10.1±6.5* | 8.9±4.9 | 0.035 |
| Hashimoto's thyroiditis (%) | 28 (50.9)‡ | 3 (5.1) | 9 (9.0) | <0.001 |
| US characteristics | ||||
| Shape | ||||
| Taller than wide | 28 (50.9) | 16 (27.1)‡ | 56 (56) | 0.002 |
| Wider than tall | 27 (49.1) | 43 (72.9) | 44 (44) | |
| Margin | ||||
| Well-defined | 0 (0.0) | 3 (5.1) | 1 (1.0) | 0.091 |
| Ill-defined | 55 (100.0) | 56 (94.9) | 99 (99.0) | |
| Echogenicity | ||||
| Marked hypoechoic | 5 (9.1) | 1 (1.7) | 4 (4.0) | 0.352 |
| Hypoechoic | 45 (81.8) | 54 (91.5) | 91 (91.0) | |
| Isoechoic | 3 (5.5) | 1 (1.7) | 2 (2.0) | |
| Hyperechoic | 2 (3.6) | 1 (1.7) | 1 (1.0) | |
| Mixed echoic | 0 (0.0) | 2 (3.4) | 2 (2.0) | |
| Calcification | ||||
| Absence | 44 (80.0)†∥ | 29 (49.2) | 58 (58.0) | 0.005 |
| Micro | 2 (3.6) | 15 (25.4) | 20 (20.0) | |
| Macro | 6 (11.0) | 7 (11.8) | 18 (18.0) | |
| Mixed | 2 (3.6) | 6 (10.2) | 4 (4.0) | |
| Rim | 1 (1.8) | 2 (3.4) | 0 (0.0) | |
| Cystic degeneration | ||||
| Present | 0 (0.0) | 0 (0.0) | 2 (2.0) | 0.316 |
| Absent | 55 (100.0) | 59 (100.0) | 98 (98.0) | |
| DTD pattern | ||||
| Present | 43 (78.2)‡ | 6 (10.2) | 9 (9.0) | <0.001 |
| Absent | 12 (21.8) | 53 (89.8) | 91 (91.0) |
FLT, focal lymphocytic thyroiditis; AH, adenomatous hyperplasia; PTC, papillary thyroid cancer; US, ultrasound; DTD pattern, "diffuse thyroid disease" pattern on US; TSH, thyrotropin; Tg-Ab, thyroglobulin antibody; TPO-Ab, thyroid peroxidase antibody.
Data are mean±SD or number of patients (%). p value by one-way ANOVA for continuous variables and χ2-test for categorical variables.
*p<0.05, †p<0.01, ††p<0.001, the comparison of the FLT or AH group with the PTC group, §The portion of the patients treated with levothyroxine or anti-thyroid drugs, ∥Comparison between the absence and the presence of calcification.