A patient who experienced thyroid storm complicated by rhabdomyolysis, deep vein thrombosis, and a silent pulmonary embolism: a case report

BACKGROUND: Thyroid storm is a serious condition of thyrotoxicosis. Hyperthyroidism often presents with thrombotic events, especially at cerebral sites; however, the possible association between a lower extremity deep vein thrombosis (LEDVT) and thyroid storm has not been previously reported. We encountered a patient who developed thyroid storm, associated with rhabdomyolysis, followed by LEDVT and a small silent pulmonary embolism (PE). The case is discussed with references to the pertinent literature. CASE PRESENTATION: A 50-year-old woman with no past medical history was referred to our hospital because of severe diarrhea, muscle weakness in her lower limbs (manual muscle testing: MMT 3), and disturbances of consciousness. She was diagnosed as having Graves’ disease based on the presence of struma, exophthalmos, and hyperthyroidism with TSH receptor antibody positivity; we further determined that the patient was experiencing thyroid storm based on the results of the Burch-Wartofsky scoring system and a Japanese diagnostic criteria. Treatment with steroids, iodine potassium, methimazole, and propranolol was initiated. Severe watery diarrhea continued, and the laboratory data revealed hypokalemia (2.0 meq/L). On day 14, a blood analysis showed a sudden elevation in her creatinine kinase (CK) level, leading to a diagnosis of rhabdomyolysis. Thereafter, the muscle weakness in her lower limbs advanced to a degree of MMT 1. Seven days after the diagnosis of rhabdomyolysis, pitting edema began to appear in bilateral lower extremities. Contrast-enhanced CT scans revealed a LEDVT involving the left common iliac vein, bilateral femoral veins, and left popliteal vein. Furthermore, a small PE was identified. Hyperthyroidism often presents with thrombotic events, especially at cerebral sites, but few reports of PE or LEDVT have been made. CONCLUSION: This case suggests that the occurrence of thyroid storm may be associated with a risk of LEDVT and/or PE. We suggest that DVT preventive measures are undertaken, and that a lower limb venous echo or contrast-enhanced CT examination would be considered if LEDVT is suspected.