US features of collapsing benign cystic nodules and papillary thyroid microcarcinomasa
| Characteristic | CBCN (n = 13) | PTMC (n = 26) | P Value |
|---|---|---|---|
| Internal content | |||
| Solid | 13 (100) | 26 (100) | |
| Shape | .016 | ||
| Ovoid-to-round | 13 (100) | 16 (62) | |
| Taller-than-wide | 10 (39) | ||
| Margin | <.000 | ||
| Spiculated | 2 (15) | 20 (76) | |
| Ill-defined | 11 (85) | 6 (23) | |
| Echogenicity | .290 | ||
| Marked hypoechogenicity | 6 (46) | 7 (26.9) | |
| Hypoechogenicity | 7 (54) | 19 (73) | |
| Microcalcification | 6 (46) | 15 (58) | .734 |
| Macrocalcification | 0 (0) | 23 (89) | .538 |
| Inner isoechoic rim | 11 (85) | 5 (19) | <.000 |
| Low-echoic halo | 10 (77) | 3 (1) | <.000 |
↵a Data are numbers of nodules, with percentages in parentheses.