Recurrent focal myositis of the thigh in a patient with end-stage kidney disease: An unusual association.

Abstract

A 40-year-old woman, with a ten-year history of diabetes and hypertension, was diagnosed with end-stage kidney disease necessitating regular hemodialysis twice weekly for the past year. The patient reported recurrent episodes of swelling and pain in the left thigh, initially treated as cellulitis. The pain was persistent and there was an ill-defined firm lump in the thigh muscle. Biopsy of the mass revealed endomysial mononuclear cell infiltrates, including lymphocytes and histiocytes, focal muscle fiber necrosis, and regeneration, indicating an inflammatory myopathy. MRI of the thigh confirmed patchy myositis with no definitive collection or mass identified. Focal myositis was diagnosed and the patient was managed expectantly with physiotherapy and analgesics. Over a span of approximately three months the condition completely resolved. Muscle pain in end-stage kidney disease often stems from causes such as peripheral neuropathy, critical lower limb ischemia, muscle cramps due to electrolyte abnormalities, and chronic infection. Focal myositis is rarely documented in literature and only a few cases of recurrent focal myositis have been reported previously in patients with end-stage kidney disease.