Table. Risk-Stratified Patient Demographic Characteristics and Diagnostic Evaluation of Ipsilateral Axillary Lymphadenopathy After COVID-19 Vaccination.
| Characteristic | Patients, No. (%) | P value | |
|---|---|---|---|
| Low risk (n = 272) | High risk (n = 36) | ||
| Age, mean (SD), y | 53 (12) | 53 (16) | .64 |
| Risk factors | |||
| Prior ipsilateral breast cancer | 0 | 23 (64) | NA |
| Suspicious ipsilateral abnormality | 0 | 3 (8) | |
| Concurrent ipsilateral breast cancer | 0 | 4 (11) | |
| Concurrent ipsilateral regional malignant neoplasm | 0 | 6 (17) | |
| Vaccine manufacturer | |||
| BioNTech-Pfizer | 153 (56) | 19 (53) | .64 |
| Moderna | 110 (40) | 16 (44) | |
| Johnson & Johnson | 6 (2) | 1 (3) | |
| Unknown or not reported | 3 (1) | 0 | |
| Time interval to initial imaging, mean (SD), wk | 4 (2) | 4 (2) | .49 |
| Screening mammogram | 153 (56) | 3 (8) | <.001 |
| Diagnostic mammogram | 52 (19) | 20 (56) | |
| Breast magnetic resonance imaging | 67 (25) | 13 (36) | |
| Warranted follow-up ultrasonography, No./total No. (%) | 13/272 (5) | 36/36 (100) | NA |
| Compliance with follow-up | 13/13 (100) | 34/36 (94) | NA |
| Time interval to follow-up imaging, mean (SD), wk | 15 (8) | 8 (4) | .001 |
| Resolution of IAL on imaging | 7/13 (54) | 22/34 (65) | .49 |
| BI-RADS assessment, No./total No. (%) | |||
| 2 | 7/13 (54) | 22/34 (65) | .73 |
| 3 | 2/13 (15) | 3/34 (9) | |
| 4 | 4/13 (31) | 9/34 (26) | |
| 5 | 0/13 (0) | 0/34 (0) | |
| Biopsy workup results, No./total No. (%) | |||
| Benign | 5/5 (100) | 12/12 (100) | NA |
| Malignant | 0/5 (0) | 0/12 (0) | NA |
Abbreviations: BI-RADS, Breast Imaging–Reporting and Data System; IAL, ipsilateral axillary lymphadenopathy; NA, not applicable.