Clinicopathological features of neonatal subcutaneous fat necrosis and its implications

Abstract

A full-term infant girl was delivered by elective caesarean section at 38 + 3 gestational weeks.Pregnancy history was unremarkable. Birth weight: 3465 grams. Apgar score was 9, 10, and 10 at 1, 5, and 10 min, respectively. There were no complications in the immediate neonatal period. On the fifth day of life, an erythematous, hard, and painless lesion (2  2 cm) in the right upper limb was detected (Fig. 1). Ultrasound revealed thickening and hyperechogenicity of the subcutaneous cellular tissue, compatible with subcutaneous fat necrosis (SCFN). Initial laboratorial studies were unremarkable, except mildly increased ionized calcium 5.53 mg/dL (reference range: 4.8-5.52 mg/dL). The patient did not receive vitamin D supplements. Subsequent laboratorial studies revealed no changes. There was spontaneous progressive reduction of the lesion and complete disappearance at 6 months.

Subcutaneous fat necrosis of the newborn: A retrospective study of 32 infants and care algorithm

“…Only one infant developed ulceration with scarring, and there were no other patients with residual skin lesions or scarring. This natural history is consistent with prior literature, which has reported rapid resolution with rare progression after being noted 3,11,13,14 …”

“…Measuring total calcium alone would have missed 86% of cases of hypercalcemia in our study population. Several published reports describing hypercalcemia in SCFN used total calcium alone, which may explain our higher rate of hypercalcemia in our population 3,8,10,14,15,16,18 …”

“…This natural history is consistent with prior literature, which has reported rapid resolution with rare progression after being noted. 3,11,13,14 Hypercalcemia is a potentially life-threatening complication of SCFN, and the underlying pathophysiology remains unclear. 15 Hypercalcemia can be detected by measuring total serum calcium levels and/or ionized serum calcium levels.…”

“…Several published reports describing hypercalcemia in SCFN used total calcium alone, which may explain our higher rate of hypercalcemia in our population. 3,8,10,14,15,16,18 Complications of hypercalcemia occurred in 20% (n = 6) of the 29 patients with hypercalcemia. Complications were defined as clinical symptoms of hypercalcemia (fussiness, poor feeding, irritability)…”