eMedicine Specialties > Radiology > Breast

Breast Cancer, Male

Author: Marilyn A Roubidoux, MD, Professor of Radiology, Department of Breast Imaging, University of Michigan Medical Center
Coauthor(s): Stephanie K Patterson, MD, Clinical Associate Professor, Department of Breast Imaging, University of Michigan Medical Center
Contributor Information and Disclosures

Updated: Sep 24, 2008

Introduction

Background

For excellent patient education resources, visit eMedicine's Cancer and Tumors Center. Also, see eMedicine's patient education articles Breast Cancer, Breast Lumps and Pain, and Breast Self-Exam.

Related eMedicine topics:

Breast Cancer (Oncology)

Breast Cancer (Plastic Surgery)

Breast Cancer, Ultrasonography

Breast Cancer, Mammography

Breast Cancer Evaluation

Pathophysiology

Males with Klinefelter syndrome have a risk of breast cancer that approaches that of females. Exogenous hormone therapy, such as treatment for prostate cancer, is not associated with an increased risk of male breast tumors; breast masses in these patients are more commonly found to be metastatic disease rather than primary breast cancer. A few transsexual patients have been reported with breast cancer 5-10 years after initiation of estrogen therapy; however, it is not known whether these patients are at an increased risk compared with non-transsexual males.^8,18

An increased risk of breast tumors was found in men exposed to estrogen-containing creams in the soap and perfume industries, and in men with gonadal injury. These epidemiologic factors, in addition to studies that suggest that men with breast cancer have elevated estriol production, indicate a relationship between male breast cancer and hormones. Case reports indicate that radiation is carcinogenic in men as well as in women.^19,20

The overwhelming histologic subtype of breast carcinoma in men is ductal or unclassified (93.7%), followed by papillary (2.6%). Infiltrating lobular carcinoma is rare in males, likely because of the rarity of terminal lobules in the male breast. Ductal carcinoma in situ is also less common among male patients with breast cancer, most likely because a higher prevalence of screening detects ductal carcinoma in situ in women. All other types of breast cancer, including medullary, colloid, cystosarcoma phyllodes, and Paget disease, are reported in males. Estrogen receptors are more commonly present in males with breast cancer than in women, occurring in 75-94% of males with cancer.^1,8

Frequency

United States

Male breast cancer is not a common condition, only accounting for approximately 1% of all breast cancers (ie, 1/100th the incidence of breast cancer in females); however, for reasons that are unclear, the incidence of male breast cancer increased from 1973-1998. Approximately 2000 patients per year are diagnosed.^{2,3,4,5,6,7,9,10,21}

International

Male breast cancer has a distribution that is similar to that of female breast cancer, with the exception being in parts of Africa. Male breast cancer is more common in Egypt, representing 6% of all breast cancers, and in Zambia, where it represents 15% of all breast cancers. This may be caused by the higher prevalence of liver diseases (from schistosomiasis or malnutrition) in these areas, with resulting increases in endogenous estrogens. The incidence is low in Japan and higher in North America and Great Britain.⁵

Mortality/Morbidity

Male breast cancer is staged similarly to that of female breast cancer. As in women, the strongest prognostic factors are axillary nodal status and tumor size, with survival rates dependent upon these factors. The 5-year survival rates range from 30-85%. A more advanced disease state is found in men more commonly than in women, which likely results from delayed detection. Relative survival rates are very similar between men and women with stage I-IV breast carcinoma. Overall survival rates for men with breast carcinoma, stratified by stage of disease, are lower than for women with breast carcinoma. At presentation, 28-60% of males have node positive disease. As in women, tumor metastases occur in the lungs, liver, and bone.^2,3,5,21

Race

The National Cancer Institute Surveillance, Epidemiology and End Results (NCI SEER) registry reports that breast cancer is found in 14 black men per million, as compared with 8 white men per million.

Sex

The male-to-female ratio for breast cancer is approximately 1:100.

Age

As in females, the risk for breast cancer increases with age; the median age is approximately 67 years. Breast cancer rarely occurs in men younger than 30 years.

Anatomy

The male breast is primarily composed of fat tissue, with a few branching ducts and connective tissue. Lobules are typically absent from the male breast, which may be the reason that lobular carcinoma is rare in males. The breast tissue in males responds to hormonal stimulation, with growth of ducts and connective tissue resulting in gynecomastia.

Presentation

Male breast cancer typically presents as a painless retroareolar mass. It is often eccentric to the nipple. Nipple discharge is rare but, when present, most likely results from the malignancy. The upper outer quadrant is the second most common site.^1,22

Gynecomastia, the chief entity in the differential, typically presents as a smooth disk centered immediately behind the nipple.

Preferred Examination

The clinical examination is key in the evaluation of a palpable mass in a male. If the clinical features strongly suggest gynecomastia, further evaluation may not be necessary. If the clinical features are equivocal, fine-needle aspiration guided by palpation and/or excisional biopsy are necessary to make the diagnosis. Accurate diagnosis with mammography alone has been reported, with a sensitivity and specificity of at least 90%. If clinical examination and mammography both reveal benign findings, a biopsy may be unnecessary. Given the rarity of male breast cancer, mammography screening guidelines are not available for men.^22,23

Ultrasonography can demonstrate a cyst in a male, but cysts are rare. A mammogram showing only fat can be helpful in cases of unilateral breast enlargement without a mass but, in general, this finding is not concerning for breast cancer and does not require further evaluation of the breast.

Magnetic resonance imaging (MRI) has not been studied regarding its sensitivity in making a diagnosis but, since the lesions are always palpable and can be biopsied easily under palpation, there is no clear role for MRI.

Limitations of Techniques

Although some mammographic findings do suggest male breast cancer (eg, an eccentric spiculated mass), mammography or ultrasonography has not been compared with the predictive value of a clinical breast examination and fine-needle aspiration. Considerable overlap also exists in the ultrsonographic appearance of these entities.⁶

Differential Diagnoses

Other Problems to Be Considered

Inflammation
Gynecomastia
Fat necrosis
Abscess

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