this could also be related to her neck problem; There was tingling and numbness down the arm and the side of her body; she was experiencing a sensation under her left arm/There was tingling and numbness down the arm and the side of her body/it can be crazy and it is pretty much always there and sometimes much intense; This spontaneous case was reported by a patient and describes the occurrence of MUSCULOSKELETAL DISCOMFORT (this could also be related to her neck problem), PARAESTHESIA (There was tingling and numbness down the arm and the side of her body) and HYPOAESTHESIA (she was experiencing a sensation under her left arm/There was tingling and numbness down the arm and the side of her body/it can be crazy and it is pretty much always there and sometimes much intense) in an adult female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 036B21A and 032M21A) for COVID-19 prophylaxis.     Question:Describe relevant medical history/conditions, allergy, concomitant diseases and risk factor.Answer:None.    On 05-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 02-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced MUSCULOSKELETAL DISCOMFORT (this could also be related to her neck problem), PARAESTHESIA (There was tingling and numbness down the arm and the side of her body) and HYPOAESTHESIA (she was experiencing a sensation under her left arm/There was tingling and numbness down the arm and the side of her body/it can be crazy and it is pretty much always there and sometimes much intense). At the time of the report, MUSCULOSKELETAL DISCOMFORT (this could also be related to her neck problem) outcome was unknown and PARAESTHESIA (There was tingling and numbness down the arm and the side of her body) and HYPOAESTHESIA (she was experiencing a sensation under her left arm/There was tingling and numbness down the arm and the side of her body/it can be crazy and it is pretty much always there and sometimes much intense) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In September 2021, Mammogram: an ultrasound and a repeat mammogram and they ruled out anything pertaining to the breast. She was told that this could also be related to her neck problem so she did PT for 3 months but it did not offer any relief. On an unknown date, Mammogram: She cannot exactly tell when the symptoms began but it was not long after getting the vaccine when she was having a mammogram in Sep2021 when she mentioned to the technician that she was experiencing a sensation under her left arm. She was advised to consult with her physician.. On an unknown date, Ultrasound scan: an ultrasound and a repeat mammogram and they ruled out anything pertaining to the breast. She was told that this could also be related to her neck problem so she did PT for 3 months but it did not offer any relief.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No concomitant medications were reported.  It was reported that patient cannot exactly tell when the symptoms began but it was not long after getting the vaccine when patient was having a mammogram in Sep2021 when patient mentioned to the technician that she was experiencing a sensation under left arm. Patient was advised to consult with her physician. There was tingling and numbness down the arm and the side of body. Patient reported that it can be crazy and it was pretty much always there and sometimes much intense.  No treatment medications were reported.