A mole/cyst like thing underneath the skin of her left breast, and after receiving the vaccine it doubled and became marble like size.; A mole/cyst like thing underneath the skin of her left breast, and after receiving the vaccine it doubled and became marble like size.; A mole/cyst like thing underneath the skin of her left breast, and after receiving the vaccine it doubled and became marble like size.; Cyst was burning; Irritation; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 54 year-old female patient received bnt162b2 (COMIRNATY), administered in arm right, administration date 08Nov2021 11:35 (Lot number: FH8020) at the age of 55 years as dose 1, single for covid-19 immunisation. Relevant medical history included: "Diabetes" (ongoing), notes: Diabetes is really high and they keep switching her diabetes medication.; "Hypertension" (ongoing), notes: In 2009 or 2010, numbers are usually 136/85-90. If does not take medication or stress it goes up.; "Hypothyroidism" (ongoing); "Hyperthyroidism" (ongoing); "Cyst" (ongoing), notes: Cyst has been present for well over a year prior to receiving her COVID-19 vaccine; "Hysterectomy", start date: 2018 (unspecified if ongoing), notes: Had uterus, cervix, right ovary and tubes that go with it removed. She still has her left ovary. Concomitant medication(s) included: LEVOTHYROXINE taken for thyroid disorder, hyperthyroidism, hypothyroidism, start date: 2001 (ongoing); ALOGLIPTIN taken for diabetes mellitus, start date: 2021 (ongoing); GLIMEPIRIDE taken for diabetes mellitus (ongoing); BASAGLAR taken for diabetes mellitus, start date: Sep2021 (ongoing); JANUVIA. Past drug history included: Metformin for Diabetes, reaction(s): "Itching", notes: Reports having to stop Metformin due to itching and red boils on skin sometime around 2009 or 2010.; Metformin for Diabetes, reaction(s): "Red boils on skin", notes: Reports having to stop Metformin due to itching and red boils on skin sometime around 2009 or 2010. Vaccination history included: Flu vaccine (Unsure but 3 weeks prior to COVID-19 vaccine), for Immunization. The following information was reported: CYST (non-serious), MELANOCYTIC NAEVUS (non-serious), CONDITION AGGRAVATED (non-serious) all with onset 09Nov2021, outcome "not recovered" and all described as "A mole/cyst like thing underneath the skin of her left breast, and after receiving the vaccine it doubled and became marble like size."; BURNING SENSATION (non-serious) with onset 09Nov2021, outcome "unknown", described as "Cyst was burning"; SKIN IRRITATION (non-serious) with onset 09Nov2021, outcome "unknown", described as "Irritation". Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: The patient was diagnosed with hypertension in 2009 or 2010. Numbers were usually 136/85-90. If did not take medication or stress it went up. The patient did not have any family medical history relevant to adverse events. The patient was taking Levothyroxine because her thyroid was taken out in 2001. Took thyroid out and replacement for thyroid. She was hyperthyroid, now she was hypothyroid. She was getting older so dose went up. After she had her thyroid taken out she started at 5mcg. The patient was taking Januvia but then was switched to alogliptin. She was no longer taking Januvia. It was not working very well and she did remember why they stopped this medication. The patient was taking 20 units of Basaglar at night but after bloodwork dose was switched. She still had her left ovary. She was informed needed one ovary for calcium. No additional vaccines were administered on same date of the Pfizer suspect. The patient received her first dose of the COVID-19 vaccine and was going to get her second dose of the COVID-19 vaccine. The patient stated that she had a cyst on her skin after taking her first COVID-19 vaccine and now wanted to know if this had something to do with the vaccine and if she should get her second dose. The cyst was under her skin and was the size of a mole and then the day after receiving her COVID-19 vaccine, 09Nov2021, she noticed irritation in that area and that the cyst was burning and was then the size of a marble, it had gotten bigger. Cyst on skin size of mole and now the size of a marble. It started with a little burning. She started touching it. The cyst was very small then like a mole. The cyst was on the base of her right breast. It had been recommended that she should see a dermatologist but she had not seen one yet. The cyst didn't grow outside. It grew inside and under the skin. Something fed it and it got big. The patient initially stated that she noticed this the following day. Also mentioned, within 10 days it was big like a marble. She did not know if she may be allergic to the COVID-19 vaccine because of this. The caller wanted to know if since the cyst got larger, whether she should she get the second vaccine. She asked if the cyst was a concern; she didn't get her second vaccination on the 29th because of the cyst on her skin and had not yet seen a recommended dermatologist. The adverse events did not require a visit to Emergency Room or Physician Office. No relevant tests were done. There was a Product complaint.  No follow-up attempts are possible. No further information is expected.