[Clinico-radiologic problems in the study of the male breast in gynecomastia]

Gynecomasty is usually classified as normal of abnormal, except for 25% of cases which are classified as idiopathic because their causes and pathogenesis remain unknown. Gynecomasty is diagnosed mainly on clinical grounds, while integrated imaging, sometimes combined with cytology, is used to distinguish benign from malignant forms. Bilateral gynecomasty is easy to diagnose, especially when patients report assuming particular drugs or present other risk factors, but unilateral or asymmetrical gynecomasty is a diagnostic problem. Primary male breast cancer usually presents as a unilateral hard mass, often infiltrating the dermis and with early lymph node metastases; it is associated with gynecomasty in 20% of cases.

We examined 76 men (age range, 15-75 years) referred for breast enlargement; the patients with radiologic findings of breast adiposis were not included in our series. All patients were submitted to standard projection mammography with a high resolution dedicated film and to real time US with high frequency probes (7.5-12 MHz).

Breast enlargement was unilateral in 48% of cases and bilateral in 52%. The radiologic patterns, compared with histologic or clinical-therapeutic follow-up, permitted the correct diagnosis in 72 of 76 patients (94%). The extant four patients had chronic inflammation (3 cases) and a malignant tumor with questionable imaging features. Overall imaging findings were: 55 cases (72%) of actual gynecomasty--unilateral in 17 and bilateral in 38 cases--9 unilateral malignant tumors (12%), eleven cases of inflammation (14%) and 1 case (2%) of unilateral metastasis from plasmocytoma. Sixteen (29%) actual gynecomasty patients (21% of the whole series) had a nodular form (unilateral in 6 and bilateral in 10 cases), 23 (42% and 30% of the whole series) had a dendritic form (unilateral in 7 and bilateral in 16 cases) and 16 (29%, 21% of the whole series) had a glandular form.

Diagnosing gynecomasty is relatively easy in the patients with bilateral forms with a positive history of associated exogenous or endogenous factors, while focal unilateral or asymmetrical forms are difficult to distinguish into benign and malignant. The radiologic pattern may be questionable especially in chronic inflammation and in some malignant forms and must therefore be integrated with cytologic or surgical findings.