has a really bad black and blue spot the size of a golf ball if not bigger; big bruise; her arm was sore; This is a spontaneous report from contactable consumer (patient). This consumer reported similar events for 4 patients. This report is for 1st of 4 patients.  A 73-years-old female received first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot number was EN6206) via an unspecified route of administration on 09Mar2021 administered in left arm (age at the time of vaccination was 73-years-old) as a DOSE 1, SINGLE dose for COVID-19 immunization; ASPIRIN [ACETYLSALICYLIC ACID] via oral route on an unspecified date for an unspecified indication. Medical history included blood pressure, anxiety and gerd from an unspecified date. Concomitant medications included unspecified blood pressure medication, unspecified medication taken for anxiety and taken for GERD. The investigation assessment was not provided. On 10Mar2021, the patient experienced her arm was sore. On 12Mar2021, the patient experienced has a really bad black and blue spot the size of a golf ball if not bigger. Additional Information: The caller said that she had a question. A week ago, today she got the first dose of the Pfizer COVID vaccine in her left arm. Since the second day after her COVID vaccine she had a really bad black and blue spot the size of a golf ball if not bigger. She did not know why that would be. It might be a little bit bigger than the size of a golf ball. It was not swollen; it was just really a big bruise. She took aspirin, she forgot to tell the lady who gave her the COVID vaccine that and she did not know if they use thinner needles if you're on a blood thinner. She didn't tell them that, so she doesn't know if that's what caused it or if they hit a capillary when she was given the COVID vaccine. She had tried to look online but didn't find any information for this. She thought to report the experience she had but she was also curious why this happened. The spot did not show up on the first day that she had received her COVID vaccine because she took the bandage off shortly after she had got home and it wasn't there then. It was tender then and it had started getting a little bit bruised on day 2. She got the COVID vaccine on 09Mar2021 and on 10Mar2021 her arm was sore. Then all of a sudden on 12Mar2021 she looked in the mirror and saw the big black and blue bruise. It is not tender or sore. She doesn't look at her upper arms every day. It was still there and that's why she called. She thinks that it was maybe 10% better. It was more blackish looking now but it is really hard to say with her age and her eyesight. The spot was dark black and blue. She said that her eyesight was not related to the COVID vaccine she has had this before the COVID vaccine. She went back on 30Mar2021 to get the final, second dose of the COVID vaccine. Her niece said that it was not unusual for that to occur if someone is on blood thinners. She knew some people who have had some side effects after their COVID vaccines. She had been taking aspirin for over 40 years. History/ Investigations: She took the full dose aspirin, anything else she took was for either blood pressure, anxiety, or for GERD. She was taking aspirin as a preventative measure because heart disease runs in her family and she takes this medication just in case. It just was her choice to take it. No doctor had prescribed it but they don't have a problem with her taking it. She declined to provide further information for the blood pressure, anxiety, or GERD medications such as start dates or actual medication names. She said no to having any relevant test results or medical conditions. Sometimes when she has gotten blood taken out of her arm, once in blue moon, she will get a bad bruise but this one seems really dark on her upper arm. She will get a bruise sometimes when they go in and get an IV or take a bunch of vials of blood work. She declined to answer any further questions for the supplemental form at this time and she asked, does she have to go to the medical information department for her question to be answered. She had to go to her primary care provider a week from Thursday and she can show them her bruise if it is even still there then. She just wants to make sure that there was no concern. Is was rare, Does it happen a lot. The clinical outcome of has a really bad black and blue spot the size of a golf ball if not bigger was recovering, while the clinical outcome of her arm was sore, big bruise was unknown.  No follow-up attempts are possible. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-2021302472 same reporter /drug, , different patient and event;US-PFIZER INC-2021300165 same reporter /drug, , different patient and event;US-PFIZER INC-2021301277 same reporter /drug, , different patient and event;US-PFIZER INC-2021300158 same reporter /drug, , different patient and event