Painful swelling in the thigh: diabetic muscle infarction

Figure 2: Magnetic resonance imaging of the patient's thigh. A: Coronal image showing diffuse, heterogeneous, intense signal of the involved muscle (arrow), which suggests edema. B: Sagittal image showing a heterogeneously enhanced mass (arrow) with peripheral enhancement after adminstration of gadolinium.

Figure 3: Muscle biopsy showing ischemic skeletal muscle fibres with areas of necrosis (black arrow), reparative changes with myofibre regeneration (white arrow), signs of fibrosis, fat necrosis and chronic inflammation. Atherosclerotic changes are seen in medium-sized vessels and fibrin thrombi are seen in the small vessels (hematoxylin–eosin stain, original magnification × 40).