To describe the clinical, histologic, and radiologic findings in patients with diabetic muscular infarction (DMI).

Descriptive case series of 3 patients with DMI and 22 previously reported cases (MEDLINE data base search) in the English literature are presented.

Diabetic muscular infarction is usually seen in patients with long-standing insulindependent diabetes and multiple end-organ microvascular complications. Two-thirds of patients with DMI are women, with a mean age at presentation of 39 ± 12 years. The typical clinical presentation includes abrupt onset of thigh pain and tenderness. There is a palpable, painful mass, with swelling and induration of the surrounding tissue without systemic symptoms or signs. The painful lesion persists for weeks, occasionally with exacerbations of symptoms, then spontaneously resolves over several weeks to months. Recurrent episodes are reported in half of the patients. Muscles commonly affected are the vastus lateralis, thigh adductors, and biceps femoris; but calf muscles may be involved as well. Active pathologic changes in the muscle are more sensitively evaluated with T2-weighted sequences on magnetic resonance (MR) imaging, which shows high intensity in involved muscle. Histologic features of DMI consist of large areas of muscle necrosis and edema. Regenerating muscle fibers and lymphocytic interstitial infiltration may be present.

Diabetic muscular infarction is a rare complication of diabetes mellitus. In most patients, the diagnosis can be made when the characteristic clinical presentation is combined with a typical MR imaging results. Muscle biopsy can be helpful in establishing the diagnosis of DMI, but histologic findings are not specific. Awareness of this syndrome plus MR imaging as the first diagnostic test should lead to the correct diagnosis and shorter hospitalization.