Rare and aggressive form of cancer; This spontaneous case was reported by a consumer and describes the occurrence of NEOPLASM MALIGNANT (Rare and aggressive form of cancer) in a 57-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 017A21A and 044A21A) for COVID-19 vaccination.     The patient's past medical history included Cyst (Skin that looked like a pimple) in January 2021 and Cyst removal (Took cyst out but didn't send it to pathologist until months later, 06-Apr-2021.) in February 2021.   On 30-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 27-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced NEOPLASM MALIGNANT (Rare and aggressive form of cancer) (seriousness criterion medically significant). At the time of the report, NEOPLASM MALIGNANT (Rare and aggressive form of cancer) outcome was unknown.     No concomitant medication details were provided.   She got tested and the value was 500 before the surgery and that number went down to 91. Patient had participated in a clinical trial. Both the professionals from the trial and her oncologist told her that her cancer was caused by a virus.  Her oncologist told her she should get the booster shot since she is on the risk group for COVID19. She was scheduled for the weekend, but since she had her treatment last Monday, she doesn't want to interfere with clinical trial results (AEs).  She had put the booster on hold, and she doesn't think she will be able to get it right now since her husband died after getting his shot.  No treatment medication details were provided.  Company Comment - This spontaneous case concerns a 57-year-old female patient with no relevant medical history who experienced serious unexpected event of neoplasm malignant. The events was diagnosed after the first dose of the Moderna COVID-19 vaccine however, the patient noticed the first symptoms prior to vaccination . Before vaccination, in January 2021, the patient noticed something weird on her skin that looked like a pimple, she consulted with a PA who told her it was a cyst and not to worry about. A month later, she went to the plastic surgeon and he took it out but didn't send it to pathologist until months later, 06Apr2021. By 27Apr2021, when she got her second dose of the vaccine, she knew she had a rare and aggressive form of cancer. Rechallenge was not applicable since the event did not resolve prior to the second dose so no rechallenge was done and thus, recurrence was not applicable.  The benefit-risk relationship of product is not affected by this report.; Sender's Comments: This spontaneous case concerns a 57-year-old female patient with no relevant medical history who experienced serious unexpected event of neoplasm malignant. The events was diagnosed after the first dose of the Moderna COVID-19 vaccine however, the patient noticed the first symptoms prior to vaccination . Before vaccination, in January 2021, the patient noticed something weird on her skin that looked like a pimple, she consulted with a PA who told her it was a cyst and not to worry about. A month later, she went to the plastic surgeon and he took it out but didn't send it to pathologist until months later, 06Apr2021. By 27Apr2021, when she got her second dose of the vaccine, she knew she had a rare and aggressive form of cancer. Rechallenge was not applicable since the event did not resolve prior to the second dose so no rechallenge was done and thus, recurrence was not applicable.  The benefit-risk relationship of product is not affected by this report