Involvement of brown adipose tissue in subcutaneous fat necrosis of the newborn

新生儿的皮下脂肪坏死(SCFN)是一种罕见的疾病，在出生几天内就会表现出来。肩周区、腋窝和肩部是最常见的受累部位，与新生儿棕色脂肪组织(BAT)的解剖部位相对应。我们推测BAT特定参与了SCFN，并在受影响的部位寻找棕色脂肪细胞。活检标本用解偶联蛋白1(UCP-1)抗体进行免疫组织化学染色，并进行电子显微镜检查。用18F-脱氧葡萄糖(18F-FDG)正电子发射断层扫描和计算机断层扫描(PET-CT)检查BAT。在两名患者的活检标本中，有几个细胞与UCP-1抗体结合，并在几个退化阶段检测到棕色脂肪细胞。PET-CT扫描显示SCFN主要部位18F-FDG摄取降低。SCFN和BAT位于同一部位，提示两者存在病理生理联系。

Subcutaneous fat necrosis (SCFN) of the newborn is a rare condition that is manifest within days of birth. The interscapular region, axillae and shoulders are the most commonly affected sites, corresponding to anatomic sites of brown fat tissue (BAT) in newborns. We postulated the specific involvement of BAT in SCFN and searched for brown adipocytes at affected sites. Biopsy specimens were immunostained with antibodies against uncoupling protein 1 (UCP-1) and examined by electron microscopy. We also examined BAT by 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomographic and computed tomographic (PET-CT) scanning. A few cells in biopsy specimens from two patients bound antibodies against UCP-1, and brown adipocytes were detected at several stages of degeneration. PET-CT scans revealed lower uptake of 18F-FDG at major sites of SCFN. SCFN and BAT can be found in the same sites, suggesting a pathophysiological connection.