Diabetic muscle infarction: an underappreciated cause of a painful swollen extremity. Evaluation with magnetic resonance imaging.

Diabetic muscle infarction (DMI) is a rarely reported complication of diabetes mellitus and usually occurs in patients with poorly controlled diabetes and/or significant end-organ complications. It is not unusual for these patients to undergo extensive work-up and treatment for thrombophlebitis, myositis, or vasculitis when DMI is not initially considered. We report the use of magnetic resonance imaging (MRI) to diagnose DMI on three occasions in two patients. We believe MRI should be considered early in the evaluation of diabetic patients with unexplained localized complaints in an extremity. In compatible clinical situations, MRI may lead to a swift diagnosis of DMI while excluding conditions requiring specific therapy. In addition, when the presentation is atypical, MRI may help focus further evaluation, i.e., localize which muscle to biopsy.