An unusual complication of subcutaneous fat necrosis of the newborn

Surgical management of subcutaneous fat necrosis of the newborn required due to a lack of improvement: a very rare case

Subcutaneous fat necrosis of the newborn (ScFN) is an uncommon and transient disease characterized by defined areas of fat necrosis and overlying cutaneous nodule lesions. It usually becomes apparent within the first 6 weeks of life in full-term or post-term infants. It is caused by generalized and/or local tissue hypoperfusion. The skin lesions of ScFN tend generally to improve spontaneously in a few weeks. We present a full-term newborn with birth distress. After therapeutic hypothermia, she presented voluminous and numerous subcutaneous fat necrosis with extensive calcifications. Surgical management was decided at her ninth month because of a total lack of regression. Hypercalcaemia, the most threatening complication, appeared only after this delayed surgery.

[Renal ultrasound in fat necrosis]

Subcutaneous fat necrosis is an uncommon disease that may be complicated with potentially fatal hypercalcemia or with nephrocalcinosis. We report on the case of a patient with a history of significant perinatal asphyxia, hospitalized for a urinary tract infection. Lesions of subcutaneous fat necrosis were noted, with asymptomatic hypercalcemia at 3.9mmol/L. A renal ultrasound was performed and showed echogenic medullary pyramids bilaterally, consistent with nephrocalcinosis and left nephrolithiasis. The treatment of hypercalcemia included hyperhydration, a diuretic and corticosteroids. Progression was characterized by the total regression of skin lesions and normalization of serum calcium. Hypercalcemia is a rare complication of subcutaneous fat necrosis. It develops within days to weeks after the appearance of skin lesions. Nephrocalcinosis appears after several weeks or months. Hypercalcemia must be treated in due time to avoid the impact on the kidney.