Male Breast: A Review of the Literature and Current State of the Art of Diagnostic Imaging Work-Up

Abstract

Pathological conditions affecting the male breast (MB) share some similarities with those found in women, while others are specific to men. The first part of this review provides an overview of MB disorders, exploring the most common types of MB diseases. The second part then emphasizes the state-of-the-art approaches proposed in the literature for screening and follow-up with MB cancer patients, which highlights the importance of tailored strategies for diagnosis, follow-up, and identifying high-risk populations. Considering the increasing attention in recent years on the topic, transgender individuals are also included in this review. Together with the MB, it is an understudied category thus far. This review aims to raise awareness among radiologists that MBs should be approached differently from female breasts, contributing to the advancement of medical knowledge, improving patient outcomes, and promoting early detection of MB disorders. The review also provides an update on breast cancer and screening in the transgender population.

Keywords: breast cancer screening; follow-up; high-risk man; male breast cancer.

Figure 1

Anatomy of male breast and mammographic appearance.

Figure 2

Right medio-lateral-oblique digital mammography of different types of male breast. (A) Pseudo-gynecomastia: the breast is almost entirely fatty. (B) Nodular gynecomastia: in the retro-areolar region, there is a nodular density that blends into the surrounding subcutaneous fat, resulting in indistinct border. (C) Dendritic gynecomastia: there are fibrous extensions of dendritic gynecomastia (flame shaped) in the breast. (D) Diffuse gynecomastia: heterogeneously dense breasts consisting of both nodular and dendritic components that closely resemble female breasts in a transgender patient receiving high-dose estrogen therapy.

Figure 3

A 35-year-old men with a palpable lump in the inner quadrants of the left breast. On a B-mode (A) breast ultrasound, there is an oval shaped and hyperechoic mass, with circumscribed margins and parallel orientation. No posterior feature is associated. On color-doppler (B), there are no signs of vascularization. The imaging features are consistent with a lipoma.

Figure 4

A 49year-old patient with a history of a blunt trauma on the right breast. In the sub-areolar region (A) of the right breast, there is a hyperechoic mass with anechoic internal components and (B) no signs of vascularization at color-doppler. (C,D) Strain elastography evaluation shows that the mass has an intermediate elasticity. The findings are consistent with fat necrosis.

Figure 5

Palpable lump on the right side in a 71-year-old man, with a personal history of type 1 diabetes and hypertension. On breast ultrasound, there is a subareolar irregular shaped and hypoechoic mass, with not-circumscribed margins and vertical orientation. No posterior feature is associated. The mass is suspicious for malignancy (BI-RADS 4b) and a core-needle biopsy was performed. Final histology: fibrosis, gynecomastia, and chronic inflammation are consistent with diabetic mastopathy.

Figure 6

An intra-mammary lymph-node in the upper-outer quadrant of the right breast of 70-year-old men. B-mode ultrasound shows the small reniform mass with a central hyperechoic fatty hilum and the hypoechoic cortex.

Figure 7

A 60-year-old man with gynecomastia presenting a retroareolar lump on the right breast with nipple retraction and without nipple discharge. Histological examination revealed an invasive ductal carcinoma (ER + 90%, PR + 60%, HER2 score 1+). Ultrasound examination (A) shows a hypoechoic irregular mass (white arrow) in the retroareolar region, with lobulated margins. A mammography (B) shows an irregular hyperdense retroareolar mass with lobulated margins (red circle).

Figure 8

Invasive papillary carcinoma in a 59-year-old man with bloody nipple discharge. Magnification of mediolateral oblique view of the right breast (A) shows a focal high-density mass with well-circumscribed margins (red circle). Ultrasound (B) shows a complex cyst with mixed solid and cystic morphologic features.

Figure 9

Mammography in cranio-caudal (A) and medio-lateral oblique (B) views in a 52-year-old transgender woman after 5 years of hormone therapy.