possible breast cancer; strong systemic reaction; throat swelling; tachycardia; rash; Repeated right breast ultrasound May 2021 due to pain and area felt larger and more tender.; Repeated right breast ultrasound May 2021 due to pain and area felt larger and more tender.; This is a spontaneous report from a contactable other HCP (Nurse, patient). A 41-year-old female patient received 2nd dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, LOT number: EJ1685, expiration date unknown) via an unspecified route of administration in the arm left on an unspecified date (reported as 18Dec2020 11:00 AM and pending clarification) at single dose for COVID-19 immunization. Patient was not pregnant at time of vaccination. Medical history included depression, anxiety, COVID-19. Patient had drug allergies to morphine and doxycycline. Patient previously received 1st dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, LOT number: EJ1685, expiration date unknown) via an unspecified route of administration in arm right on 18Dec2020 at 11:00 AM (as reported) at age of 41-year-old at 0.3 ml, single dose for COVID-19 immunization and had strong systemic reaction. The patient didn't receive any other vaccines within 4 weeks prior to the COVID vaccine. Patient had usual regimen (unspecified) within 2 weeks of vaccination. It was reported that patient had strong systemic reaction with both doses. 2nd injection was sent straight from the employee health to Emergency Room due to throat swelling, tachycardia and rash. The most concerning was the area under her right Axilla found about 5 months ago. It's was originally a small bean size area. Patient had seen her primary care physician and she could felt it so got a mammogram and breast ultrasound and the radiologist did see and confirm area but felt it was related to her recent COVID 19 vaccine. There was no family history breast issues. Patient had repeated right breast ultrasound in May2021 due to pain and area felt larger and more tender. Patient had an additional area of concern moving her to BARDS 3 concerning for possible breast cancer. Patient would repeat ultrasound in 1 month so Jun2021. Patient had never had any issues and had no family history. The events resulted in doctor or other healthcare professional office/clinic visit and emergency room/department or urgent care. Patient had emergency room visit and multiple PCP as treatment for the events. Seriousness criteria of the events was reported as disability or permanent damage. Outcome of the events was not recovered. Prior to vaccination, the patient was diagnosed with COVID-19. Since the vaccination, the patient hasn't been tested for COVID-19.; Sender's Comments: Based from temporal occurrence of events and vaccination schedule, the causal association of reported events in relation to suspected drug BNT162B2 cannot be totally excluded   The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate