Statin-induced, immune-mediated necrotising myopathy triggered by malignancy successfully treated with immunosuppression

Abstract

Statin-induced immune-mediated necrotising myopathy (IMNM) is an inflammatory myopathy that can present as proximal muscle weakness and, in some cases, as dysphagia and respiratory distress. In this report, we present a case of statin-induced IMNM in a 78-year-old male. The patient had significantly high levels of creatinine kinase and myoglobinuria and experienced gradual weakness in the proximal muscles for 1 month after initiating a 20 mg dose of Atorvastatin 10 months before admission. Rapid clinical improvement was observed with the use of high-dose glucocorticoids in conjunction with methotrexate.

Keywords: Dysphagia; Glucocorticoid; Methotrexate; Myopathy; Myositis; Statins.

Fig. 1

CT chest-abdomen-pelvis with contrast showed Slightly bulky prostate (white arrow) with no evidence of metastatic disease.

Fig. 2

The hip MRI reveals diffuse bilateral symmetrical muscle oedema involving multiple muscle groups involving gluteus medius, gluteus maximus, rectus femoris, vastus lateralis, hamstring muscles, anterior compartment of the lower leg bilaterally. There is no fat infiltration of any of the muscle groups within the lower limbs. This appearance is suggestive of diffuse myositis.

Fig. 3

Serial measurements of creatine kinase levels (in U/L) in the patient's serum were taken from the time of admission to the hospital with escalation of immunosuppression.