Dermatology Department, Clínica Universidad de Navarra, Madrid, Spain.
Pathology Department, Hospital Infantil Universitario Niño Jesús, Madrid, Spain.
J Dtsch Dermatol Ges. 2021 Jan;19(1):73-80. doi: 10.1111/ddg.14322. Epub 2021 Jan 14.
Clinicopathological features of cutaneous neurofibromas presenting as large irregularly shaped congenital café-au-lait macules (CALM) in Neurofibromatosis type 1 (NF1) patients have not been well characterized. We aimed to analyze the histopathological findings of large "atypical" CALM in children with NF1.
In this retrospective observational study we analyzed histopathological and immunostaining features of 21 biopsy specimens from 18 large hyperpigmented macules with irregular borders with or without hypertrichosis present during the first months of life in NF1 diagnosed children.
Of the 21 biopsies, ten showed a diffuse neurofibroma pattern and four exhibited characteristics of plexiform neurofibroma (PNF). In twelve specimens we observed groups of fusiform cells arranged linearly mimicking a small caliber nerve trunk with abnormal morphology. Repeated biopsies from two of these lesions performed at different ages showed transformation to a plexiform pattern. An increased interstitial cellularity was observed in 17 samples that was more evident around eccrine glands in 16 or accompanying hair follicles and vascular structures in twelve samples. All these cells had immunoreactivity for S100-protein, CD68 and were Melan-A positive in 15 samples.
Clinicopathological findings of congenital cutaneous neurofibromas provide early diagnostic clues of NF1 with high relevance for monitoring of these patients.
在 1 型神经纤维瘤病（NF1）患者中，表现为大而不规则形状的先天性牛奶咖啡斑（CALM）的皮肤神经纤维瘤的临床病理特征尚未得到很好的描述。我们旨在分析 NF1 患儿中大型“非典型”CALM 的组织病理学表现。
在这项回顾性观察性研究中，我们分析了 18 名 NF1 诊断患儿出生后前几个月存在边界不规则的大色素沉着斑伴或不伴多毛症的 21 份活检标本的组织病理学和免疫组化特征。
21 份活检标本中，10 份显示弥漫性神经纤维瘤模式，4 份表现为丛状神经纤维瘤（PNF）特征。在 12 份标本中，我们观察到成束的梭形细胞呈线性排列，类似于异常形态的小口径神经干。对其中 2 个病变进行了不同年龄的重复活检，显示出向丛状模式的转变。17 份标本中观察到间质细胞增多，16 份标本中更明显围绕着外分泌腺，12 份标本中伴有毛囊和血管结构。所有这些细胞均对 S100 蛋白、CD68 有免疫反应性，在 15 份标本中对 Melan-A 呈阳性。
先天性皮肤神经纤维瘤的临床病理发现为 NF1 提供了早期诊断线索，对这些患者的监测具有重要意义。
