Abstract：
A 4-month-old male presented for a large, hypertrichotic brown patch on the upper back with several scattered 0.5-1.5 cm, round to oval, brown macules and patches on the trunk and extremities. The lesion was initially diagnosed as a giant congenital melanocytic nevus based on clinical exam and histopathology with immunohistochemical stains. The patient was later diagnosed with neurofibromatosis type 1, and the lesion on the back developed a \"bag of worms\" texture consistent with a plexiform neurofibroma and found to harbor a pathogenic variant in the NF1 gene. This case highlights the diagnostic challenge of differentiating these lesions and their overlapping clinical and histopathological features.
摘要：
一个4个月大的男性，上背部有几个分散的0.5-1.5厘米的棕色斑块，圆形到椭圆形，棕色斑疹和在躯干和四肢上的斑块。根据临床检查和组织病理学和免疫组织化学染色，该病变最初被诊断为巨大的先天性黑素细胞痣。该患者后来被诊断为1型神经纤维瘤病，背部病变形成与丛状神经纤维瘤一致的“蠕虫袋”质地，并发现NF1基因中含有致病性变异。此病例突出了区分这些病变及其重叠的临床和组织病理学特征的诊断挑战。
