Table 2. Clinical, Biochemical, and Sonographic Characteristics of the FLT Group, Compared with the PTC Group, According to Nodule Size.
| Nodule size <10 mm | Nodule size ≤10 mm | |||||
|---|---|---|---|---|---|---|
| FLT (n=45) | PTC (n=66) | p value | FLT (n=10) | PTC (n=34) | p value | |
| Clinical and biochemical characteristics | ||||||
| Age (yrs) | 54.0±11.3 | 51.6±11.4 | 0.281 | 54.9±11.9 | 54.2±11.3 | 0.815 |
| Sex (male:female) | 4:41 | 3:63 | 0.355 | 10:0 | 29:5 | 0.573 |
| Current medications (%)* | 3 (6.7) | 1 (1.5) | 0.153 | 1 (10.0) | 0 (0.0) | 0.233 |
| T3 (ng/dL) | 156.3±43.5 | 147.5±35.1 | 0.284 | 120.3±20.3 | 155.5±32.4 | 0.012 |
| FreeT4 (ng/dL) | 1.4±1.2 | 1.4±1.2 | 0.978 | 0.8±0.3 | 1.8±1.8 | 0.001 |
| TSH (µIU/mL) | 5.7±11.2 | 1.9±1.4 | 0.033 | 4.8±6.7 | 1.8±1.2 | 0.044 |
| Tg-Ab positive (%) | 27 (64.3) | 6 (9.1) | <0.001 | 6 (60.0) | 10 (29.4) | 0.133 |
| TPO-Ab positive (%) | 23 (54.8) | 12 (18.2) | <0.001 | 5 (50.0) | 10 (29.4) | 0.271 |
| Nodule diameter (mm) | 6.0±2.0 | 6.1±1.6 | 0.858 | 14.4±0.7 | 14.4±0.5 | 0.553 |
| US characteristics | ||||||
| Shape | ||||||
| Taller than wide | 25 (55.6) | 48 (72.7) | 0.061 | 3 (30.0) | 8 (23.5) | 0.692 |
| Wider than tall | 20 (44.4) | 18 (27.3) | 7 (70.0) | 26 (76.5) | ||
| Margin | ||||||
| Well-defined | 0 (0.0) | 0 (0.0) | 1.000 | 0 (0.0) | 1 (2.9) | 1.000 |
| Ill-defined | 45 (100.0) | 66 (100.0) | 10 (100.0) | 33 (97.1) | ||
| Echogenicity | ||||||
| Marked hypoechoic | 5 (11.1) | 1 (1.5) | 0.045 | 0 (0.0) | 3 (8.8) | 0.668 |
| Hypoechoic | 36 (80.0) | 63 (95.9) | 9 (90.0) | 28 (82.4) | ||
| Isoechoic | 2 (4.4) | 1 (1.5) | 1 (10.0) | 1 (2.9) | ||
| Hyperechoic | 2 (4.4) | 0 (0.0) | 0 (0.0) | 1 (2.9) | ||
| Mixed echoic | 0 (0.0) | 1 (1.5) | 0 (0.0) | 1 (2.9) | ||
| Calcification | ||||||
| Present | 10 (22.2) | 22 (33.3) | 0.204 | 1 (10.0) | 20 (58.8) | 0.010 |
| Absent | 35 (77.8) | 44 (66.7) | 9 (90.0) | 14 (41.2) | ||
| Cystic degeneration | ||||||
| Present | 0 (0.0) | 1 (1.5) | 0.407 | 0 (0.0) | 1 (2.9) | 1.000 |
| Absent | 45 (100.0) | 65 (98.5) | 10 (100.0) | 33 (97.1) | ||
| DTD pattern | ||||||
| Present | 36 (80.0) | 5 (7.6) | <0.001 | 7 (70.0) | 4 (11.8) | 0.001 |
| Absent | 9 (20.0) | 61 (92.4) | 3 (30.0) | 30 (88.2) | ||
PTC, papillary thyroid cancer; FLT, focal lymphocytic thyroiditis; TSH, thyrotropin; Tg-Ab, thyroglobulin antibody; TPO-Ab, thyroid peroxidase antibody; DTD pattern, "diffuse thyroid disease" pattern on US; US, ultrasound.
Data are mean±SD or number of patients (%). p value by Student's t-test or Mann-Whitney U test for continuous variables and χ2-test or Fisher exact test for categorical variables.
*The portion of the patients treated with levothyroxine or anti-thyroid drugs.