Literature on male breast pathology is limited due to it’s rarity, and current management algorithms are based on evidence from female breast cancer [1]. However, the differential for nipple discharge in males can be simply divided between those associated with breast masses vs everything else. Everything else being infectious causes like breast abscess or mastitis, hormonal/pituitary causes like prolactinoma and hypothyroidism, and medication side effect— classically antipsychotics.

In a study by Sloane Kettering among 430 patient presenting with nipple discharge only 3% were male, however up to 57% of these men had an underlying malignancy, compared to 16% for females. Other smaller studies have found cancer rates between varying between 15-75% [2]. Benign breast masses that can cause nipple discharge include Duct Ectasia (benign dilatation) and Intraductal Papilloma. Although Intraductal papilloma (IP) is the most common cause of bloody nipple discharge in females, only 11 cases of IP in the male breast have been reported in the literature [3]. Still, the presence of bloody nipple discharge is often associated with malignancy. A 2012 meta-analysis reported a breast cancer risk of 52% vs 19% for bloody vs non bloody discharge respectively [4]. Although more complicated diagnostics such as Ductoscopy are preformed to analyze nipple discharge, in the ED we can simply test for the presence of blood with a guaiac card. If positive, think breast cancer. If you suspect breast cancer, you can follow the same imaging guidelines for females, typically a breast ultrasound, mammography or MRI. Prompt referral to a breast surgeon for biopsy should then be made. Unfortunately, due to lack of awareness, male breast cancer tends to present in a more advanced state, with up to 40% being stage III or IV [5].

Take home points: Nipple discharge in men carries a high probability of underlying malignancy. Since men do not often present until late, a finding of bloody nipple discharge should prompt further imaging studies such as ultrasound, mammography or MRI. Provide appropriate follow up with a breast surgeon for definitive diagnosis.

Case Conclusion by Louis Jamtgaard (@Lgaard)



References:

[1] Gradishar W. Breast cancer in Men. UpToDate. Accessed 12-1-15.

[2] Morrogh M. Breast Journal, 2009. 15 (6): 632–638

[3] Shim J. Journal of Ultrasound in Medicine September 2008 27:1397-1400

[4] Chen L. Breast Cancer Res Treat 2012; 132:9.

[5] Culell P. Breast J. 2007 Mar;13(2):213-5