Subcutaneous fat necrosis (SFN) in the newborn is a rare, transient inflammatory disorder of adipose tissue attributed to perinatal stress such as birth trauma, asphyxia, meconium aspiration, or exposure to cold.1- 3 Prolonged hypothermic cardiac surgery, maternal diabetes, and preeclampsia are associated with SFN.2- 3 The disease is characterized by indurated, nonsuppurative, erythematous or violaceous mobile subcutaneous masses with taut overlying skin. The face, trunk, buttocks, and proximal extremities are the typical locations of lesions.4 Subcutaneous fat necrosis usually develops within the first several weeks of life, most frequently between the 5th and 10th days, and is usually self-limited. Hypercalcemia may be associated with SFN and represents the most serious complication; undetected hypercalcemia may have a fatal outcome. Other complications include nephrocalcinosis and nephrolithiasis.5 The pathogenesis of SFN is poorly understood, and in many affected infants no provocative factors have been identified. The disorder does not occur in all infants who are at risk.