Imaging the Male Breast: Gynecomastia, Male Breast Cancer, and Beyond.

The number of men undergoing breast imaging has increased in recent years, according to some reports. Most male breast concerns are related to benign causes, most commonly gynecomastia. The range of abnormalities typically encountered in the male breast is less broad than that encountered in women, given that lobule formation rarely occurs in men. Other benign causes of male breast palpable abnormalities with characteristic imaging findings include lipomas, sebaceous or epidermal inclusion cysts, and intramammary lymph nodes. Male breast cancer (MBC) is rare, representing up to 1% of breast cancer cases, but some data indicate that its incidence is increasing. MBC demonstrates some clinical features that overlap with those of gynecomastia, including a propensity for the subareolar breast. Men with breast cancer tend to present at a later stage than do women. MBC typically has similar imaging features to those of female breast cancer, often characterized by an irregular mass that may have associated calcifications. Occasionally, however, MBC has a benign-appearing imaging phenotype, with an oval shape and circumscribed margins, and therefore most solid breast masses in men require tissue diagnosis. Histopathologic evaluation may alternatively reveal other benign breast masses found in men, including papillomas, myofibroblastomas, and hemangiomas. Radiologists must be familiar with the breadth of male breast abnormalities to meet the rising challenge of caring for these patients. ©RSNA, 2024 Supplemental material is available for this article.

Axillary adenopathy following COVID-19 vaccination: A single institution case series.

Axillary adenopathy is a potential side effect following COVID-19 vaccination. We report four cases of axillary adenopathy in the setting of recent COVID-19 vaccination (Moderna and Pfizer-BioNTech) at our institution. Our cases show unilateral axillary adenopathy, as well as adenopathy persisting for two to three weeks following vaccination. The Society of Breast Imaging (SBI) and Harvard University have each released guidelines for management of axillary adenopathy following COVID-19 vaccination. While SBI recommends short term imaging 4-12 weeks following the second dose, a group of physicians from Harvard suggest clinical follow-up with sonographic imaging if clinical concern persists beyond six weeks. As a larger percentage of the general population becomes vaccinated, it is important for radiologists to be aware of potential vaccine-induced ipsilateral axillary adenopathy on screening and diagnostic breast imaging to reduce the number of unnecessary biopsies performed in this patient population.