A 4-year-old boy presented with a pink nodule on his left cheek. The lesion started as a hyperpigmented macule 3 years ago and since then had been gradually increasing in size and developing into a pink nodule. The lesion was pruritic at times and sometimes bled with minor trauma. The boy was otherwise healthy, with an unremarkable medical history and with no history of trauma or exposure to radiation. On physical examination, there was a 1-cm well-circumscribed, symmetrical, pinkish, dome-shaped nodule with central erosions on the left cheek (Figure 1). Hair, nails, and mucosae were of normal appearance, and the remainder of the examination was unremarkable.

中文翻译：

---

男孩左脸颊上的粉红色结节

一名 4 岁男孩因左脸颊出现粉红色结节就诊。病变开始于 3 年前的色素沉着斑块，此后逐渐增大并发展为粉红色结节。病变有时会瘙痒，有时会因轻微外伤而出血。男孩其他方面都很健康，没有明显的病史，也没有外伤或辐射暴露史。体格检查发现，左脸颊有一 1 cm 边界清楚、对称、呈粉红色、圆顶状的结节，中央有糜烂（图 1）。头发、指甲和粘膜外观正常，其余检查无异常。