nonpalpable contralateral breast cancer recurrence; Malignant Axillary Adenopathy; This literature-non-study case was reported in a literature article and describes the occurrence of BREAST CANCER (nonpalpable contralateral breast cancer recurrence) in an 82-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Concurrent medical conditions included Breast cancer (Personal BC history reported on the right).    On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, the patient experienced BREAST CANCER (nonpalpable contralateral breast cancer recurrence) (seriousness criterion medically significant) and LYMPHADENOPATHY (Malignant Axillary Adenopathy). At the time of the report, BREAST CANCER (nonpalpable contralateral breast cancer recurrence) and LYMPHADENOPATHY (Malignant Axillary Adenopathy) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Biopsy: 5 mm maximum lymph node cortical thickness Biopsy revealed maximum lymph node cortical thickness of 5 mm and Metastatic BC. On an unknown date, Magnetic resonance imaging breast: breast cancer the adenopathy was the presenting symptom of a nonpalpable contralateral breast cancer recurrence. On an unknown date, Mammogram: unilateral left axillary adenopathy Left unilateral axillary adenopathy was initially detected with annual screening mammography(ASM) and BI-RADS category 4. On an unknown date, Ultrasound scan: 2 abnormal lymph nodes Initial ultrasound findings revealed 2 abnormal lymph nodes and left unilateral axillary adenopathy. and focal hypoechoic cortical lobulation sonographic findings were focal hypoechoic cortical lobulation and preserved fatty hilum.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered BREAST CANCER (nonpalpable contralateral breast cancer recurrence) and LYMPHADENOPATHY (Malignant Axillary Adenopathy) to be related.    The time between second dose to initial ultrasound was 12.0  week and initial ultrasound to biopsy decision was reported as 0.0  week. In this patient, biopsy was recommended from 12.0 to 13.1 weeks after the second vaccine dose. Patient exhibited maximal cortical thickness of at least 5 mm and highly suspicious sonographic features of either focal cortical lobulation or complete loss of the fatty hilum. Company comment: This literature case concerns an 82-year-old, female patient with concurrent medical history of Breast cancer, who experienced the unexpected, serious (Medically significant) event of Breast cancer. The exact date of administration of second dose of mRNA-1273 and onset of the event was not specified, hence latency could not be assessed. On an unknown date, biopsy was done which revealed 5 mm maximum lymph node cortical thickness and maximum lymph node cortical thickness of 5 mm and metastatic breast cancer. MRI was also done on an unknown date which revealed breast cancer the adenopathy was the presenting symptom of a nonpalpable contralateral breast cancer recurrence, mammogram was also done which showed unilateral left axillary adenopathy, left unilateral axillary adenopathy was initially detected with annual screening mammography and BI-RADS category 4 and ultrasound was also done which revealed 2 abnormal lymph nodes Initial ultrasound findings revealed two abnormal lymph nodes and left unilateral axillary adenopathy and focal hypoechoic cortical lobulation sonographic findings were focal hypoechoic cortical lobulation and preserved fatty hilum. According to the study, imaging should be done more than 16 weeks after the administration of second dose to let the adenopathy subside. The patient' concurrent medical condition of Breast cancer could be a confounder to the event. The benefit-risk relationship of mRNA-1273 is not affected by this report. Events' seriousness retained as per source document.   This case was linked to US-MODERNATX, INC.-MOD-2022-580131, US-MODERNATX, INC.-MOD-2022-580126 (Linked Report).; Sender's Comments: This literature case concerns an 82-year-old, female patient with concurrent medical history of Breast cancer, who experienced the unexpected, serious (Medically significant) event of Breast cancer. The exact date of administration of second dose of mRNA-1273 and onset of the event was not specified, hence latency could not be assessed. On an unknown date, biopsy was done which revealed 5 mm maximum lymph node cortical thickness and maximum lymph node cortical thickness of 5 mm and metastatic breast cancer. MRI was also done on an unknown date which revealed breast cancer the adenopathy was the presenting symptom of a nonpalpable contralateral breast cancer recurrence, mammogram was also done which showed unilateral left axillary adenopathy, left unilateral axillary adenopathy was initially detected with annual screening mammography and BI-RADS category 4 and ultrasound was also done which revealed 2 abnormal lymph nodes Initial ultrasound findings revealed two abnormal lymph nodes and left unilateral axillary adenopathy and focal hypoechoic cortical lobulation sonographic findings were focal hypoechoic cortical lobulation and preserved fatty hilum. According to the study, imaging should be done more than 16 weeks after the administration of second dose to let the adenopathy subside. The patient' concurrent medical condition of Breast cancer could be a confounder to the event. The benefit-risk relationship of mRNA-1273 is not affected by this report. Events' seriousness retained as per source document. US-MODERNATX, INC.-MOD-2022-580126:Patient 1:59 years old US-MODERNATX, INC.-MOD-2022-580131:Patient 2:56 years old