cancer relapse/ PAT scan indicated cancer through all his body; difficulty to sleep; leg was swollen with water; This spontaneous case was reported by a consumer and describes the occurrence of NEOPLASM MALIGNANT (cancer relapse/ PAT scan indicated cancer through all his body) in a 78-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Throat cancer (positive diagnosis for throat cancer /tongue cancer. He had it under control for over a few years) and Cancer (positive diagnosis for throat cancer /tongue cancer. He had it under control for over a few years).    On 02-Jul-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, the patient experienced NEOPLASM MALIGNANT (cancer relapse/ PAT scan indicated cancer through all his body) (seriousness criterion hospitalization), INSOMNIA (difficulty to sleep) and PERIPHERAL SWELLING (leg was swollen with water). The patient was treated with PEMBROLIZUMAB at an unspecified dose and frequency and LENVATINIB at an unspecified dose and frequency. At the time of the report, NEOPLASM MALIGNANT (cancer relapse/ PAT scan indicated cancer through all his body), INSOMNIA (difficulty to sleep) and PERIPHERAL SWELLING (leg was swollen with water) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Positron emission tomogram: abnormal (abnormal) PAT scan indicated cancer through all his body.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.       Relevant concomitant medication was taking by the patient for his illness but the name was not provided. Patient felt something wrong, neck felt stiff, severe pain, chin hurt, all on the left side where he received the vaccine, left neck, on his left under arm two lumps appeared, lymph nodes on the left side swollen with water, PAT scan indicated cancer through all his body, body too weak for the chemo, difficulty to sleep and leg was swollen with water after vaccination. He was experiencing a lot of pain and receiving anti-inflammatory medications. He was still suffering for all this pain. Treatment for chemotherapy only once as his body was too week. Patient went to ER a couple of times checked to the hospital and went back confirmed he had relapse. Treatment information was also included as anti-inflammatory medication.  Company comment: This spontaneous case concerns a 78-year-old, male patient with relevant medical history of Throat/Tongue cancer reported, who experienced the serious (Hospitalisation) unexpected event of Neoplasm malignant, which occurred unspecified days after receiving first dose of mRNA-1273 Vaccine. Patient has previous history of Throat/Tongue cancer which was under control for over a few years and after vaccination his neck felt stiff, had severe pain in the neck and chin, two lumps appeared under arm and had swollen lymph nodes filled with water, all on the side of vaccination (left). Patient also had difficulty to sleep, and his leg was swollen with water. PAT scan indicated cancer through all his body. Patient's relapse of cancer was confirmed at hospital and was treated with Pembrolizumab, Lenvatinb and anti-inflammatory drugs. Patient is still suffering from pain. Medical history of Throat/Tongue cancer could be confounder for the event. Elderly age of the patient could be risk factor for the event. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2022-517832 (Patient Link).; Sender's Comments: This spontaneous case concerns a 78-year-old, male patient with relevant medical history of Throat/Tongue cancer reported, who experienced the serious (Hospitalisation) unexpected event of Neoplasm malignant, which occurred unspecified days after receiving first dose of mRNA-1273 Vaccine. Patient has previous history of Throat/Tongue cancer which was under control for over a few years and after vaccination his neck felt stiff, had severe pain in the neck and chin, two lumps appeared under arm and had swollen lymph nodes filled with water, all on the side of vaccination (left). Patient also had difficulty to sleep, and his leg was swollen with water. PAT scan indicated cancer through all his body. Patient's relapse of cancer was confirmed at hospital and was treated with Pembrolizumab, Lenvatinb and anti-inflammatory drugs. Patient is still suffering from pain. Medical history of Throat/Tongue cancer could be confounder for the event. Elderly age of the patient could be risk factor for the event. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.