Endocrine Evaluation of Adolescent Gynecomastia
In adolescents with gynecomastia and physical examination consistent with physiologic pubertal gynecomastia, routine endocrine evaluation is not indicated; however, serum prolactin measurement should be offered if there is delayed puberty, growth arrest, or visual field loss, and a selective hormonal work-up (FSH, LH, testosterone, estradiol) is warranted only when clinical features suggest pathologic causes. 1
Clinical Assessment First
Physical examination alone can diagnose most cases of adolescent gynecomastia without imaging or extensive laboratory testing. 1
- Gynecomastia presents as a soft, rubbery, or firm mobile mass directly under the nipple and is often bilateral in approximately 50% of patients 1
- Pubertal gynecomastia is physiologic and self-limited in 75-90% of adolescents, regressing over 1-3 years 2, 3
- The condition occurs commonly during three phases: neonatal period, puberty, and senescence, with an underlying hormonal imbalance between estrogen and androgen action at breast tissue 4, 5
When to Pursue Endocrine Evaluation
Selective laboratory work-up is indicated only when clinical features suggest non-physiologic causes: 1, 6, 5
Measure serum prolactin if:
- Delayed puberty (>2 standard deviations later than mean population age) 1
- Growth or pubertal arrest 1
- Visual field loss or headache 1
- Primary amenorrhea in genetic males with disorders of sexual development 1
Measure basal gonadotropins (FSH, LH) and testosterone if:
- Testicular examination reveals abnormally small or asymmetric testes 7
- Signs of hypogonadism beyond isolated gynecomastia 5
- Suspected central precocious puberty (secondary sexual characteristics before age 9) 7
- No testicular enlargement despite other pubertal signs (suggests peripheral precocious puberty) 7
Additional hormonal assessment (estradiol, hCG, tumor markers) if:
- Rapid progression or unilateral presentation 6
- Hard, fixed, or eccentric mass (concern for malignancy) 1
- Suspected endocrine tumors (testicular exam abnormalities) 6, 5
- Chronic liver disease, renal insufficiency, or medication use that could cause hormonal imbalance 5
Common Pitfalls to Avoid
Do not confuse pseudogynecomastia (excess fatty tissue) with true glandular gynecomastia - physical examination can differentiate these, and imaging is not routinely needed 1
Do not order extensive endocrine panels in typical pubertal gynecomastia - more than 95% of adolescent cases are idiopathic and physiologic, with secondary causes accounting for less than 5% 3, 4
Do not delay specialized referral when red flags are present - boys with visual field defects, severe growth arrest, or signs of pituitary disease require urgent pediatric endocrinology evaluation 1, 7
Recognize that isolated premature adrenarche is not central precocious puberty - isolated pubic hair without testicular enlargement (>4 mL volume or >2.5 cm length) suggests adrenal androgen production rather than gonadotropin axis activation and does not require the same endocrine work-up 7
Management Based on Evaluation
For physiologic pubertal gynecomastia confirmed by clinical assessment: 2, 3, 4
- Reassurance and observation are the first-line approach, as spontaneous regression occurs in 84% of mild cases, 47% of moderate cases, and 20% of severe cases within 1-3 years 3
- Medical therapy with tamoxifen may be considered for persistent cases causing substantial tenderness or psychological distress, but is most effective when given early in the disease course and for small to moderate breast enlargement 2, 6
- Surgical correction (combining liposuction and mammary adenectomy) should be reserved for gynecomastia persisting beyond 2 years or causing severe emotional distress 6, 3
For pathologic gynecomastia identified through selective evaluation: 1, 5