What happened, in summary

A man in his early 70s went to his primary-care doctor after 2 weeks of bloody discharge from his right nipple. His history included occupational exposure to X-rays, and his daughter had developed breast cancer in her 40s. He was diagnosed with ductal carcinoma in situ, or DCIS, of the right breast.

DCIS is a non-invasive breast cancer in which abnormal cells remain within the milk ducts rather than growing into the surrounding breast tissue. It is uncommon in men. Unlike many women, men do not usually undergo routine breast screening, so symptoms such as a breast lump, nipple change or bloody nipple discharge may be what leads to investigation.

His situation was reviewed by a multidisciplinary breast-cancer team. The group recommended consultation about genetic testing, a discussion of the possible benefits and side effects of chemoprevention, and consideration of continued breast imaging. These decisions were approached through shared decision-making because evidence for managing male DCIS is limited and is often adapted from care used for women.

He chose not to start chemoprevention at that time. Instead, he entered annual mammographic surveillance of the remaining left breast. The plan focused on detecting a new change early while avoiding preventive medication he did not wish to take.

His follow-up plan therefore centered on annual imaging of the left breast and specialist review. The right-sided diagnosis remained non-invasive, so the immediate focus was future risk management rather than systemic treatment. Ongoing surveillance reflected his choice after discussing genetic assessment and preventive medication with the team.