breast carcinoma; this is a spontaneous report received from contactable healthcare professional (hcp). a 45 year-old female patient (not pregnant) received bnt162b2 (comirnaty), intramuscular, administration date dec2021 (lot number: unknown) as dose 3 (booster), single for covid-19 immunisation. there was no relevant medical history. concomitant medications were not reported. vaccination history included: comirnaty (dose number: 2, batch/lot no: unknown. not available/provided to reporter at the time of report completion), administration date: jun2021, for covid-19 immunisation; comirnaty (dose number: 1, batch/lot no: unknown. not available/provided to reporter at the time of report completion), administration date: may2021, for covid-19 immunisation. the patient did not receive any other vaccines within 4 weeks prior to the covid vaccine. prior to vaccination, the patient was not diagnosed with covid-19. the following information was reported: breast carcinoma (hospitalization in jan2022, life threatening) with onset jan2022. the patient underwent regular gynecological testing a month after the third dose of the comirnaty vaccine in jan2022. digital mammography, ultrasound and palpation showed an oversized tumor in the right breast and an urgent biopsy was decided which confirmed malignancy in jan2022. the event breast carcinoma was evaluated at the physician office visit. a mastectomy was performed, the other imaging and hematological examinations showed no signs of other malignancy or metastasis in jan2022. after the surgical recovery, the patient has already started chemotherapy. the outcome of the event breast carcinoma was recovering. since the vaccination, it was unknown if the patient been tested for covid-19. no follow-up attempts are possible; information about lot/batch number cannot be obtained. no further information is expected.; sender's comments: the event breast carcinoma is considered as intercurrent condition and unrelated to product bnt162b2 (comirnaty)

test date: 202201; test name: biopsy; result unstructured data: test result:confirmed malignancy; test date: 202201; test name: hematological examinations; result unstructured data: test result:showed no signs of other malignancy or metastasis; test date: 202201; test name: other imaging; result unstructured data: test result:showed no signs of other malignancy or metastasis; test date: 202201; test name: digital mammography; result unstructured data: test result:oversized tumor in the right breast; test date: 202201; test name: ultrasound; result unstructured data: test result:oversized tumor in the right breast

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