When visiting a patient with breast pain, beware of unnecessary mastectomy or minimally invasive rotational excision. The criteria we have for excisional examination are cystic or solid masses or suspicious malignant calcifications in the breast, 5 mm or more, as shown by ultrasound. Small cysts can continue to be observed without surgery unless they are clusters of large grape-like cystic lesions, based on the fact that cysts are mostly benign lesions and are a manifestation of endocrine disorders. Nipple overflow is mostly a manifestation of endocrine disorders, except for bloody overflow, which requires close attention, but all others can be treated with medication on a trial basis, without the need for urgent surgical excision. Plasmacytoid mastitis, mostly non-lactating mastitis, is characterized by recurrent episodes and the treatment principle is different from that of lactating mastitis. Localized advanced breast cancer may present as a painless lump larger than 5 centimeters on the breast, and immediate surgical excision is prudent because it may lead to tumor dissemination. Axillary masses often present as paronychia, paramyelitis, and enlarged lymph nodes in the pectoralis muscle group and central group. Paronychia and paronychia usually do not require surgical treatment unless paronychia has developed granulomatous changes and abnormal cells are found on cytologic examination. Painless enlarged lymph nodes of the pectoralis muscle group and central group can be treated with a trial of fine-needle cytology and further investigation if there are abnormal findings.