What is fat necrosis?
Subcutaneous fat necrosis is a benign process that often presents as a palpable subcutaneous nodule on the extremities or torso with or without an antecedent event. Two typical sonographic appearances have been ascribed to fat necrosis located within the subcutaneous soft tissues. The first is a well-defined isoechoic mass with a hypoechoic halo; the second is an ill-defined hyperechoic region.
