small clot at top of her right great saphenous vein (but nothing in lung); excruciating, sharp pain on right abdomen to neck; sharp pain on right abdomen to neck; right leg excruciatingly painful; left arm from elbow to shoulder was bright red; right leg was swollen; leg felt hard, solid, swollen, and firm; This spontaneous case was reported by a patient and describes the occurrence of THROMBOSIS (small clot at top of her right great saphenous vein (but nothing in lung)), ERYTHEMA (left arm from elbow to shoulder was bright red), PERIPHERAL SWELLING (right leg was swollen), LIMB DISCOMFORT (leg felt hard, solid, swollen, and firm) and ABDOMINAL PAIN (excruciating, sharp pain on right abdomen to neck) in an 82-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 030L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included PRAVASTATIN SODIUM (PRAVASTATIN [PRAVASTATIN SODIUM]) and CYANOCOBALAMIN (B12-VITAMIN) for an unknown indication.   On 16-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 13-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 14-Feb-2021, the patient experienced ERYTHEMA (left arm from elbow to shoulder was bright red), PERIPHERAL SWELLING (right leg was swollen), LIMB DISCOMFORT (leg felt hard, solid, swollen, and firm) and PAIN IN EXTREMITY (right leg excruciatingly painful). On 16-Feb-2021, the patient experienced ABDOMINAL PAIN (excruciating, sharp pain on right abdomen to neck) and NECK PAIN (sharp pain on right abdomen to neck). On an unknown date, the patient experienced THROMBOSIS (small clot at top of her right great saphenous vein (but nothing in lung)). The patient was treated with APIXABAN (ELIQUIS) in February 2021 for Venous thrombosis, at an unspecified dose and frequency. At the time of the report, THROMBOSIS (small clot at top of her right great saphenous vein (but nothing in lung)), ERYTHEMA (left arm from elbow to shoulder was bright red), PERIPHERAL SWELLING (right leg was swollen), LIMB DISCOMFORT (leg felt hard, solid, swollen, and firm), ABDOMINAL PAIN (excruciating, sharp pain on right abdomen to neck), PAIN IN EXTREMITY (right leg excruciatingly painful) and NECK PAIN (sharp pain on right abdomen to neck) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In February 2021, Computerised tomogram: abnormal (abnormal) Small clot at the to of right great saphenous vein. In February 2021, Ultrasound scan: abnormal (abnormal) Small clot at the to of right great saphenous vein.         On 17 FEB 2021, patient called her physician as she believed she had pulmonary embolism. On unknown date she had ultrasound and CT scan, which identified a small clot at top of her right great saphenous vein (but nothing in lung).  Based on current available information and the temporal association between product use and the start date of the events a causal relationship cannot be excluded.; Sender's Comments: Based on current available information and the temporal association between product use and the start date of the events a causal relationship cannot be excluded.