摘要目的:总结婴幼儿先天性色素痣的临床及病理特征。方法:回顾性分析2015年1月至2020年1月在西京皮肤医院确诊的126例婴幼儿先天性色素痣患儿的临床及病理资料。计数资料比较采用 χ2检验。 结果:126例婴幼儿先天性色素痣患儿中，男68例，女58例；86.5%的患儿出生即有皮损；57.9%就诊年龄2 ~ 3岁。皮损发生部位包括头面部（76例，60.3%）、躯干（24例，19.1%）、四肢（26例，20.6%）。36例（28.6%）为先天性小痣，68例（54.0%）为M1型中型痣，13例（10.3%）为M2型，9例（7.1%）为巨痣。121例（96.0%）皮损单发，5例（4.0%）多发，44例（34.9%）痣伴粗毛，15例（11.9%）伴丘疹/增生性结节，6例（4.8%）有卫星灶。病理亚型包括混合痣120例（95.2%）、皮内痣4例（3.2%）和交界痣2例（1.6%）。38例（30.1%）镜下皮损深度< 1 mm，61例（48.4%）1 ~ 2 mm，25例（19.8%）> 2 mm，45例（35.7%）浸润至皮下脂肪层或更深。126例色素痣皮损中，常见病理特征包括痣组织成熟现象（100%，不包括2例交界痣），角质层色素颗粒（42.1%），分布紊乱/不对称（63.5%），表皮痣细胞散在分布（72.2%）和呈Paget样扩散（53.2%），真皮可见噬黑素细胞（56.4%），痣细胞沿毛囊皮脂腺分布（65.1%）等。特殊病理特征包括痣细胞嵌入血管/淋巴管腔内（33.3%）、痣细胞松解（35.7%）、纤维瘤样改变（19.8%）、累及立毛肌（24.6%）、肥大细胞浸润（23.8%）等。不同临床表现的婴幼儿先天性色素痣病理模式：浸润深度> 2 mm、角质层色素颗粒和角质层柱状色素颗粒在巨痣中的发生率明显高于其他大小皮损（ χ2 = 7.93、10.76、5.89，均 P < 0.05）；浸润深度> 2 mm、表皮海绵水肿伴痣细胞散在分布、痣细胞巢沿毛囊皮脂腺分布、纤维瘤样改变、肥大细胞浸润在伴有粗毛皮损中的发生率明显高于不伴粗毛者（ χ2 = 28.29、8.11、6.22、7.92、8.19，均 P < 0.01）；表皮痣细胞呈Paget样扩散、痣细胞有异型性在伴丘疹/增生性结节的皮损中的发生率高于不伴丘疹增生性结节的皮损（ χ2 = 4.92、6.30，均 P < 0.05）。 结论:婴幼儿先天性色素痣的临床及组织病理具有独特性，细胞常见不典型性，确诊及治疗选择需要密切结合临床与病理特征。

abstractsObjective:To analyze clinical and histopathological characteristics of infantile congenital melanocytic nevi (ICMN) .Methods:Clinical and pathological data were collected from 126 infants with confirmedly diagnosed congenital melanocytic nevi in Department of Dermatology, Xijing Hospital from January 2015 to January 2020, and were retrospectively analyzed. Chi-square test was used for comparisons of enumeration data.Results:Among the 126 patients with ICMN, 68 were males and 58 were females; 109 (86.5%) presented with skin lesions at birth; 73 (57.9%) were 2 - 3 years old at the first clinic visit. The skin lesions occurred on the head and face (76 cases, 60.3%) , trunk (24 cases, 19.1%) or extremities (26 cases, 20.6%) . There were 36 (28.6%) patients with small congenital nevi, 68 (54.0%) with M1-type medium-sized nevi, 13 (10.3%) with M2-type medium-sized nevi and 9 (7.1%) with giant nevi. Of 126 cases of ICMN, 121 (96.0%) had solitary lesions, 5 (4.0%) had multiple lesions, 44 (34.9%) had nevi with coarse hairs, 15 (11.9%) had nevi complicated by papules or hyperplastic nodules, and 6 (4.8%) had satellite lesions. Pathological subtypes included compound nevus (120 cases, 95.2%) , intradermal nevus (4 cases, 3.2%) , and junctional nevus (2 cases, 1.6%) . Under the microscope, the depth of the skin lesions was < 1 mm in 38 (30.1%) cases, 1 - 2 mm in 61 (48.4%) and > 2 mm in 25 (19.8%) , and 45 (35.7%) cases showed nevus cells infiltrating the subcutaneous fat layer or deeper tissues. Among the 126 ICMN lesions, common pathological features included nevus tissue maturation (100%, 2 cases of junctional nevi were excluded) , pigment granules in the stratum corneum (53 cases, 42.1%) , disordered/asymmetric distribution of nevus cells (80 cases, 63.5%) , scattered epidermal nevus cells (91 cases, 72.2%) , pagetoid spread of epidermal nevus cells (67 cases, 53.2%) , melanophages in the dermis (71 cases, 56.4%) , and nevus cells distributed along hair follicles/sebaceous glands (82 cases, 65.1%) . Special pathological features included nevus cells embedded in the vascular/lymphatic vessels (42 cases, 33.3%) , nevus cell lysis (45 cases, 35.7%) , fibromatous changes (25 cases, 19.8%) , involvement of the arrector pilli muscles (31 cases, 24.6%) , and mast cell infiltration (30 cases, 23.8%) . Pathological patterns of ICMN with different clinical features: the incidences of infiltration depth > 2 mm, pigment granules and columnar pigment granules in the stratum corneum were significantly higher in the giant nevi than in the small and medium-sized nevi ( χ2 = 7.93, 10.76, 5.89 respectively, all P < 0.05) ; the incidences of infiltration depth > 2 mm, epidermal spongiosis with scattered nevus cells, nevus cell nests distributed along the hair follicles/sebaceous glands, fibromatous changes and mast cell infiltration were significantly higher in the skin lesions with coarse hairs than in those without ( χ2 = 28.29, 8.11, 6.22, 7.92, 8.19 respectively, all P < 0.01) ; the incidences of pagetoid spread of epidermal nevus cells and atypical nevus cells were significantly higher in the skin lesions with papules/hyperplastic nodules than in those without papules/hyperplastic nodules ( χ2 = 4.92, 6.30 respectively, both P < 0.05) . Conclusions:The clinical and histopathological characteristics of ICMN are unique, and atypical nevus cells are common in ICMN. The diagnosis and treatment of ICMN need to be based on the combination of clinical and pathological characteristics.