mammographically occult right breast invasive lobular carcinoma; ''abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary; This literature-non-study case was reported in a literature article and describes the occurrence of INVASIVE LOBULAR BREAST CARCINOMA (mammographically occult right breast invasive lobular carcinoma) and BREAST CANCER METASTATIC (''abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary) in a 79-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis.       No Medical History information was reported.    In 2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In 2021, the patient experienced INVASIVE LOBULAR BREAST CARCINOMA (mammographically occult right breast invasive lobular carcinoma) (seriousness criterion medically significant) and BREAST CANCER METASTATIC (''abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary) (seriousness criterion medically significant). At the time of the report, INVASIVE LOBULAR BREAST CARCINOMA (mammographically occult right breast invasive lobular carcinoma) and BREAST CANCER METASTATIC (''abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Magnetic resonance imaging: diagnosed with a mammographically occult right breast invasive lobular carcinoma identified on subsequent MRI. In 2021, Mammogram: identified with axillary lymphadenopathy. In 2021, Ultrasound scan: demonstrated an abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary..     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant and treatment medications were not reported.  Women with 18 years of age and older who had a documented COVID-19 vaccination and abnormal axillary lymph nodes on imaging between January 1, 2021 and February 28, 2021 were included in the study. Of the 2941 patients imaged with a screening or diagnostic mammogram, US, or MRI exam during the study period, 57 women (57/2941, 1.9%) were identified with axillary lymphadenopathy and a reported COVID-19 mRNA vaccination. Author concluded that management of lymphadenopathy should be based on patient risk factors, history of malignancy, suspicious ipsilateral breast findings, and lymph node morphology.  Company comment: This literature non study case concerns a 79-year-old, female patient with no medical history information reported, who experienced the unexpected serious (medically significant) event of invasive lobular breast carcinoma and breast cancer metastatic. The events occurred approximately 6 days after the first dose of mRNA-1273. As reported, 79-year-old woman presenting for screening mammography was recalled for right axillary lymphadenopathy. She had received the first dose of the Moderna vaccine in the left arm 6 days prior to her screening mammogram. Ultrasound demonstrated an abnormal type 6 lymph node, and biopsy revealed metastatic carcinoma consistent with breast primary. She was subsequently diagnosed with a mammographically occult right breast invasive lobular carcinoma identified on subsequent MRI which also demonstrated the malignant node. No further information about the events was provided. Considering the very short timeframe (6 days) for cancer development since first vaccination and finding of metastases of occult breast carcinoma it is likely that the condition was pre-existing and causality is assessed as not related to mRNA-1273. The benefit-risk relationship of mRNA-1273 is not affected by this report.   This case was linked to US-MODERNATX, INC.-MOD-2023-732122 (Linked Report).   Most recent FOLLOW-UP information incorporated above includes: On 06-Jul-2023: Live follow up received by safety on 06-Jul-2023, contains significant information.; Sender's Comments:  US-MODERNATX, INC.-MOD-2023-732122:Master case