Skin nontumor
Panniculitis
Subcutaneous fat necrosis of newborn
Last author update: 1 August 2011
Last staff update: 28 August 2020
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PubMed Search: Subcutaneous fat necrosis of newborn
Table of Contents
Definition / general | Clinical features | Case reports | Microscopic (histologic) description | Electron microscopy description | Additional referencesCite this page: Hamodat M. Subcutaneous fat necrosis of newborn. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorsubcutaneousfatnecrosisofnewborn.html. Accessed March 24th, 2023.
Definition / general
- Uncommon disorder of infants in good health with lesions on trunk, extremities, buttocks, cheeks
- Hypercalcemia has been reported in some cases; thrombocytopenia, hypoglycemia and hypertriglyceridemia may also develop
- Lactic acidosis and hyperferritinemia were each present in one case
- Numerous possible causes, including obstetrical trauma, hypothermia, asphyxia, anemia, forceps delivery, macrosomia, exposure to active or passive smoking during pregnancy, prostaglandin E administration, maternal exposure to cocaine or calcium channel blockers
Clinical features
- Indurated areas and distinct nodules with a predilection for the cheeks, shoulders, buttocks, thighs and calves
Case reports
- Two cases (Dermatol Online J 2004;10:12)
Microscopic (histologic) description
- Basophilic fat necrosis, clusters of needle like clefts in lipocytes and histiocytes
- Clefts may contain refractile crystals
- Variable granulomatous inflammation and small calcium deposits
- Normal epidermis and dermis with an underlying lobular panniculitis
- Focal fat necrosis is present and this may lead to fat cyst formation
- Lymphocytes, histiocytes, foreign body giant cells and sometimes a few eosinophils wedged between the fat cells
- Many fat cells retain their outline but contain fine, eosinophilic cytoplasmic strands and granules, between which are narrow clefts radiating from a point near the periphery of the cell; clefts contain doubly refractile crystals, representing triglycerides, on frozen section
- Similar fine, needle-like crystals can be seen in giant cells
- Older lesions have fibrosis between fat cells
Electron microscopy description
- Intact and necrotic fat cells containing needle-shaped crystals arranged radially or in parallel
- Dense granular material is also present in necrotic fat cells, which are surrounded by macrophages
Additional references
