melanonychia

例句：

1. 1. She had a melanonychia on her left arm that she was very concerned about.
   她的左臂上有一个黑毛痣，她对此非常担心。
2. 2. The doctor found a melanonychia on his patient's neck and advised him to have it removed.
   医生在他的病人脖子上发现了一个黑色素痣，并建议他把它切除。
3. 3. The melanonychia on her cheek was so dark that it almost looked like a tattoo.
   她脸颊上的黑色素痣太黑了，几乎看起来像是纹身。