Researchers from the University of Toronto have documented a rare instance of gigantomastia—abnormal and excessive breast growth—following the administration of the Pfizer COVID-19 vaccine.
A 19-year-old woman, previously healthy with no notable medical history, experienced rapid breast enlargement just one week after receiving her first dose of the Pfizer COVID-19 vaccine in September 2022.
Her condition worsened following the second dose, with her breast size increasing dramatically from a B cup to a triple G over six months.
Social media users have dubbed this unusual case the “Pfizer Boob Job.”
Despite undergoing extensive medical evaluations, no hormonal abnormalities or other causes were identified.
Doctors determined that the woman’s symptoms aligned with pseudoangiomatous stromal hyperplasia (PASH), a rare condition involving idiopathic fibrous mammary tissue growth.
The association between PASH and vaccine administration has not been previously established, making this case particularly noteworthy.
According to the medical journal:
This case presents a healthy young woman with rapid bilateral breast enlargement 1 week following Pfizer COVID-19 vaccine administration. After ruling out other potential causes, she underwent bilateral reduction mammoplasty, with histology revealing dense terminal duct lobular units interspersed with PASH.
The patient believed that the vaccine caused her breast