Report of 2 Novel Presentations of Subcutaneous Fat Necrosis of the Newborn

Abstract

Subcutaneous fat necrosis of the newborn (SCFNN) is a rare form of panniculitis classically affecting healthy full-term infants. There are a number of predisposing factors including perinatal asphyxia. The condition generally has a benign course with spontaneous resolution, but monitoring for metabolic complications, in particular the potentially life-threatening complication of hypercalcaemia, is critical. The authors report 2 cases of preterm infants with perinatal asphyxia with atypical presentations of SCFNN: the first with bony involvement resembling Langerhans cell histiocytosis and with follicular pseudocarcinomatous hyperplasia on histology; and the second presenting with a huge haematoma requiring surgical debridement. Both cases were initially erroneously diagnosed as pyogenic infections.

Clinicopathological features of neonatal subcutaneous fat necrosis and its implications

“…Subcutaneous fat necrosis of the newborn is an uncommon disorder, with self-limiting panniculitis presenting in the first few weeks after birth as wide erythematous plaques or firm non-tender subcutaneous nodules, which most commonly affect the limbs, buttocks, back, cheeks, and areas over bony prominences [1,2].…”

“…In more severe cases, systemic corticosteroids and bisphosphonates have been used. When SCFN is not associated with hypercalcaemia, the treatment of this dermatosis is symptomatic, requiring the avoidance of vitamin D supplementation [1][2][3].…”

Subcutaneous nodules in an infant

“…The presence of doubly refractile needleshaped clefts within adipocytes is a characteristic finding. 4 The main differential diagnosis of SCFN is sclerema neonatorum (SN). In contrast to SCFN, SN classically presents in critically ill, preterm infants with rapidly expansive hardening of the skin during the first few weeks of life.…”

Subcutaneous fat necrosis in a 14‐day‐old neonate presenting with multiple ulcers

“…Kannenberg et al. , also reported a novel case of SFNN in a preterm male neonate who required surgical management 5 …”