Melanocytic nevus - 黑素细胞痣 https://en.wikipedia.org/wiki/Nevus
黑素细胞痣 (Melanocytic nevus) 是一种含有痣细胞的黑素细胞肿瘤。大多数痣出现在人生的前二十年。约每 100 名婴儿中就有 1 名在出生时即有痣。获得性痣属于良性肿瘤,而先天性痣被视为轻度畸形或错构瘤,且其黑色素瘤风险相对较高。良性痣呈圆形或椭圆形,大小通常在 1–3 毫米之间,但有些可达约 5 毫米,即铅笔橡皮的大小。有些痣带有毛发。

治疗
激光通常用于美容性去除小痣。当痣直径大于 4–5 毫米时,常需手术切除。对于幼儿而言,直径超过 2 毫米的痣往往难以在不留下疤痕的情况下完全去除。
#CO2 laser
#Er-YAG laser
更多信息 ― 简体中文
References Effective Treatment of Congenital Melanocytic Nevus and Nevus Sebaceous Using the Pinhole Method with the Erbium-Doped Yttrium Aluminium Garnet Laser 25324667 
NIH
Congenital melanocytic nevus 是一种黑素细胞痣,通常在出生时或婴儿期后出现。皮脂腺痣被认为是胚胎期毛囊皮脂腺单位发育缺陷导致的错构瘤。本文介绍了利用针孔技术和 Erbium:YAG 激光治疗不同患者痣病变的方法。
Congenital melanocytic nevus (CMN) is a melanocytic nevus that is either present at birth or appears during the latter stages of infancy. Nevus sebaceous has been described as the hamartomatous locus of an embryologically defective pilosebaceous unit. Here, we describe how we used the pinhole technique with an erbium-doped yttrium aluminium garnet (erbium : YAG) laser to treat nevi lesions in different patients.
 Malignant Melanoma 29262210 
NIH
黑色素瘤是一种肿瘤,由黑色素细胞(负责肤色的细胞)癌变形成。黑色素细胞起源于神经嵴。这意味着黑色素瘤不仅可以在皮肤上生长,还可以在神经嵴细胞迁移至的其他部位(例如胃肠道和大脑)中出现。早期(0 期)黑色素瘤患者的生存率高达 97%,而晚期(IV 期)患者的生存率则大幅下降至约 10%。
A melanoma is a tumor produced by the malignant transformation of melanocytes. Melanocytes are derived from the neural crest; consequently, melanomas, although they usually occur on the skin, can arise in other locations where neural crest cells migrate, such as the gastrointestinal tract and brain. The five-year relative survival rate for patients with stage 0 melanoma is 97%, compared with about 10% for those with stage IV disease.