Pubertal gynaecomastia

A degree of gynaecomastia is common and physiological in pubertal males, affecting up to 40% of males in Tanner Stage 3 or 4 (testicular volume 10 to 15 mL as assessed using an orchidometer). A pathological cause is rare. However, Klinefelter syndrome¹ or other causes of male hypogonadism should be considered, especially if gynaecomastia occurs in Tanner Stage 1 or 2 (discordant with normal physiology).

Observation and reassurance are required. No medical therapy has been shown to be successful. Plastic surgery may be required for persistent significant breast enlargement, but should be delayed until late puberty because recurrence may occur. Patients with Klinefelter syndrome have an increased risk of breast cancer (albeit later in life), so surgical referral should be strongly considered.

Any gynaecomastia occurring in a prepubertal male requires urgent referral; see Precocious puberty.