lump under her arm; arm was sore; lymph node/very swollen lump/potential lymph node under her arm on the side she received the vaccine; This is a spontaneous report from a contactable consumer (Patient). A 65-years-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Formulation: Solution for injection, Lot number: EL8982), via an unspecified route of administration, administered in Arm Right on 08Feb2021 (Age at vaccination 65 years) as dose 2, single for Covid-19 immunization. Medical history included none. There were no concomitant medications. The patient previously took first dose of bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Lot number : EL3302, Expiry date: Unknown), via an intramuscular route of administration on 18Jan2021(Age at vaccination 65 years) in arm right as dose 1, single for Covid-19 immunisation and flu shot but that was months before. Patient stated no concomitant, just the normal stuff she takes every day. Time the Vaccination Was Given: around noon, around 11:30-12pm. Vaccination facility type was clinic. Additional Vaccines was not administered on Same Date of the Pfizer Suspect. Patient did not receive any other vaccines within 4 weeks prior to the Covid vaccine. On an unspecified date, the patient experienced lump under her arm; arm was sore and on 10Feb2021, lymph node/very swollen lump/potential lymph node under her arm on the side she received the vaccine. It was reported that patient received the 2nd dose on Monday at noon. This morning, she has noticed a lump under her arm on the side she received the vaccine. She described it as 'pretty darn big', 'not quite the size of a tennis ball'. she received her second dose of Pfizer vaccine on Monday at noon. She hasn't had too bad of side effects. She showered Monday night and didn't shower yesterday. However, her arm was sore and she didn't really touch anything or notice anything. This morning, as she was showering and washing under her arm on the side where she received vaccine, she felt a lump probably the size of a cutie, a little size of a tennis ball. She states she believes its a lymph node, but its pretty darn swollen. It's not in the pit of her arm, its more so towards the front around the same spot where the vaccine was administered. It's really a difficult thing. she did call her brother in law who is a retired physician who believes it's probably a lymph node. Patient stated the lymph node was not hard at all. When she feels it and lifts her arm up, she can feel the tissue when she presses it and stuff. It's not super sensitive that was why she probably didn't notice it before. When she felt it this morning, she was like "that was weird. When she discovered nothing like that was on the other side, she definitely figured out it was a lump.Patient did not performed any lab test. Patient did not visited to emergency room and physician office. Her doctor doesn't really know anything. They doctors are kind of in the dark and don't know much about it. She feels like she is at a loss. She called the facility where she was given the vaccine and they just blew her off and don't know. Investigation Assessment: No. The clinical outcome of event lymph node/very swollen lump/potential lymph node under her arm on the side she received the vaccine was not recovered; while other events were outcome were unknown.  Follow-up attempts completed. No further information expected.