The patient was a 53-year-old man. Thirty years ago, the patient had a mung bean-sized red papule on the inner side of his left nipple without obvious inducement. The papule gradually increased in size, but there were no conscious symptoms. In the past year, the patient experienced erosion and a scab appeared in the center of the lesion. As a result, he visited our clinic ( Figure 1A ). There was no family history with similar symptoms. The patient had tuberculosis in the right chest wall 30 years ago and was cured back then.