Left arm is light pink; One hour after the shot her entire left arm is hard like a rock /hard; Same night of the shot, there was an area of the left arm two half dollars in size/ that area is now 5 or 6 inches; Right after receiving the shot her left arm started itching; One hour after the shot her left arm started swelling /was round / still swelling; This spontaneous case was reported by a consumer and describes the occurrence of VACCINATION SITE DISCOLOURATION (Left arm is light pink), VACCINATION SITE INDURATION (One hour after the shot her entire left arm is hard like a rock /hard), VACCINATION SITE MASS (Same night of the shot, there was an area of the left arm two half dollars in size/ that area is now 5 or 6 inches), VACCINATION SITE PRURITUS (Right after receiving the shot her left arm started itching) and VACCINATION SITE SWELLING (One hour after the shot her left arm started swelling /was round / still swelling) in a 59-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 013H21B, 002A21A and 042L20A) for COVID-19 vaccination.     Concurrent medical conditions included Hypothyroidism, Diabetes, Allergy to nuts, Iodine allergy and Latex allergy. Concomitant products included METFORMIN for Diabetes, LEVOTHYROXINE for Hypothyroidism.   On 29-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 01-Jan-2022, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 01-Jan-2022, the patient experienced VACCINATION SITE DISCOLOURATION (Left arm is light pink), VACCINATION SITE INDURATION (One hour after the shot her entire left arm is hard like a rock /hard), VACCINATION SITE MASS (Same night of the shot, there was an area of the left arm two half dollars in size/ that area is now 5 or 6 inches), VACCINATION SITE PRURITUS (Right after receiving the shot her left arm started itching) and VACCINATION SITE SWELLING (One hour after the shot her left arm started swelling /was round / still swelling). The patient was treated with PARACETAMOL (TYLENOL [PARACETAMOL]) for Adverse event, at an unspecified dose and frequency; IBUPROFEN for Adverse event, at an unspecified dose and frequency and DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) for Adverse event, at an unspecified dose and frequency. At the time of the report, VACCINATION SITE DISCOLOURATION (Left arm is light pink) and VACCINATION SITE PRURITUS (Right after receiving the shot her left arm started itching) outcome was unknown and VACCINATION SITE INDURATION (One hour after the shot her entire left arm is hard like a rock /hard), VACCINATION SITE MASS (Same night of the shot, there was an area of the left arm two half dollars in size/ that area is now 5 or 6 inches) and VACCINATION SITE SWELLING (One hour after the shot her left arm started swelling /was round / still swelling) had not resolved.            Patient reported that the area of the left arm which was two half dollars in size was changed to 5 or 6 inches on 03 Jan 2022. Patient had nothing abnormal after first and second dose.