Radiology

Case: Malignant Male Breast Lesions

By Amy Zhang, MD and James Chalfant, MD

Introduction, Demographics, Clinical Presentation

Male patients with breast symptoms often present with a palpable lump, tenderness, or breast enlargement, and the majority (99%) who undergo imaging have benign findings1. Male breast cancer is rare, with <1% of all breast cancers diagnosed in men2. Given the very low incidence of male breast cancer, screening mammography is not routinely recommended in men. 

The average age at diagnosis of male breast cancer is 67 years, approximately 5 years older than the average age at diagnosis in women3,4, with incidence increasing with age. Additional risk factors associated with breast cancer in men include family history of breast cancer, high estrogen levels (e.g., Klinefelter syndrome), and radiation exposure4. BRCA1 and BRCA2 mutation carriers have increased risk of breast cancer, for example with 6.8% age-adjusted cumulative risk of breast cancer in men with BRCA2 mutation at age 70 years5. 

A painless, palpable breast mass is the most common clinical presentation of male breast cancer3. Other signs and symptoms include nipple discharge, nipple retraction, and palpable axillary lymph nodes4. According to the ACR Appropriateness Criteria, diagnostic mammography and ultrasound are usually appropriate for initial imaging of a male patient of any age with physical exam suspicious for breast cancer (suspicious palpable breast mass, axillary adenopathy, nipple discharge, nipple retraction)6. For male patients 25 years of age or older with indeterminate palpable breast masses (not highly suspicious on physical exam), diagnostic mammography is usually appropriate as the initial imaging exam (ultrasound “may be appropriate”). Ultrasound is usually appropriate for patients younger than 25 years of age, while diagnostic mammography may be appropriate.

Spectrum of Malignant Lesions of the Male Breast

Invasive Ductal Carcinoma

The most common histologic subtype of male breast cancer is invasive ductal carcinoma of no special type (85% of cases)1. On mammography, this often appears as a high-density round, oval or irregular subareolar mass with margins that may be circumscribed, indistinct, spiculated, or microlobulated3. Microcalcifications are seen in 13-30% of cases, less commonly than in females3.

Typically, ultrasound demonstrates a solid, hypoechoic mass. An eccentric location relative to the nipple can be a helpful distinguishing feature from gynecomastia1. 

Case: Malignant Male Breast Lesions Figure 1
Figure 1: 38 yo M with breast lump. Mammogram (CC, left and MLO, right) demonstrated an oval mass in the left breast retroareolar region.
Case: Malignant Male Breast Lesions Figure 2
Figure 2: Targeted ultrasound showed a hypoechoic mass in the retroareolar region, which was biopsied under ultrasound guidance with pathology results of invasive ductal carcinoma.

Ductal carcinoma in situ (DCIS)

Ductal carcinoma in situ of the breast accounts for approximately 5 to 10% of male breast cancers2,4. Many of these cases are associated with invasive carcinoma, with a minority of cases representing pure DCIS2. 

Other Subtypes of Invasive Breast Cancer

Invasive lobular carcinoma is rare in men, accounting for 1.5% of cases3. This low incidence is thought to be related to a lack of terminal breast lobules. 

Other rare subtypes of invasive breast cancer in men include papillary, medullary, and mucinous subtypes. 

Lymphoma

Lymphoma of the breast may be primary or secondary. Mammographic findings may include a solitary mass, multiple masses, or multiple intramammary and axillary lymph nodes7. Sonographic features of malignant lymph nodes include absent fatty hila and cortical thickening.

 

Other Cancers

Metastatic disease or direct extension of other malignancies to the breast can also occur but are uncommon4.

References:

  1. Chen L, Chantra PK, Larsen LH, Barton P, Rohitopakarn M, Zhu EQ, Bassett LW. "Imaging Characteristics of Malignant Lesions of the Male Breast." Radiographics. 2006 Jul-Aug;26(4):993-1006. doi: 10.1148/rg.264055116. PMID: 16844928.
  2. Yen PP, Sinha N, Barnes PJ, Butt R, Iles S. "Benign and Malignant Male Breast Diseases: Radiologic and Pathologic Correlation." Can Assoc Radiol J. 2015 Aug;66(3):198-207. doi: 10.1016/j.carj.2015.01.002. Epub 2015 Jun 12. PMID: 26073217.
  3. Chau A, Jafarian N, Rosa M. "Male Breast: Clinical and Imaging Evaluations of Benign and Malignant Entities with Histologic Correlation." Am J Med. 2016 Aug;129(8):776-91. doi: 10.1016/j.amjmed.2016.01.009. Epub 2016 Feb 1. PMID: 26844632.
  4. Nguyen C, Kettler MD, Swirsky ME, Miller VI, Scott C, Krause R, Hadro JA. "Male Breast Disease: Pictorial Review with Radiologic-pathologic Correlation." Radiographics. 2013 May;33(3):763-79. doi: 10.1148/rg.333125137. PMID: 23674773.
  5. Khan NAJ, Tirona M. "An Updated Review of Epidemiology, Risk Factors, and Management of Male Breast Cancer." Med Oncol. 2021 Mar 15;38(4):39. doi: 10.1007/s12032-021-01486-x. PMID: 33721121.
  6. Expert Panel on Breast Imaging:; Niell BL, Lourenco AP, Moy L, Baron P, Didwania AD, diFlorio-Alexander RM, Heller SL, Holbrook AI, Le-Petross HT, Lewin AA, Mehta TS, Slanetz PJ, Stuckey AR, Tuscano DS, Ulaner GA, Vincoff NS, Weinstein SP, Newell MS. "ACR Appropriateness Criteria® Evaluation of the Symptomatic Male Breast." J Am Coll Radiol. 2018 Nov;15(11S):S313-S320. doi: 10.1016/j.jacr.2018.09.017. PMID: 30392600.
  7. Iuanow E, Kettler M, Slanetz PJ. "Spectrum of Disease in the Male Breast." AJR Am J Roentgenol. 2011 Mar;196(3):W247-59. doi: 10.2214/AJR.09.3994. PMID: 21343472.