Gynecomastia is a common condition and represents a benign proliferation of glandular tissue of the male breast. Gynecomastia occurs in three different age groups - neonatal, pubertal and elderly. Due to transplacental passage of estrogen, transient stimulation of breast tissue occurs in infancy.

Pubertal gynecomastia has a peak incidence in males age 13-14 years and is probably due to an imbalance of estrogen and androgens. Involution generally occurs by 16-17 years. In adult males, gynecomastia increases with advancing age. The degree of gynecomastia is dependent on the hormonal environment, the intensity and duration of stimulation and the sensitivity of breast tissue to hormonal stimulation.  There are several pathologic conditions associated with gynecomastia (Table 3.1).

Clinical Features
Patients with gynecomastia present with unilateral or bilateral breast enlargement. There may be associated pain and tenderness. Gynecomastia may also be detected as an incidental finding on physical examination. It may be a source of embarrassment, particularly in young males. Clinical examination will confirm the presence of a firm disc of tissue deep to the nipple and areolar that may be tender. It is usually easy to distinguish gynecomastia from carcinoma of the breast in older men on clinical examination.

Associated skin dimpling and nipple retraction with nipple discharge are features suggesting carcinoma. If in doubt, radiologic and histopathologic investigations are mandatory. A thorough history and detailed physical examination of breasts, abdomen and testes is essential. Gynecomastia should be differentiated from pseudogynecomastia in which enlargement of the breast occurs due to fat deposition rather than glandular proliferation.

Pathology
Macroscopic Appearance
The gross appearance is ill-defined. The consistency of the tissue is that of firm breast tissue.

Microscopic Appearance
Classically, there is a ductal and a stromal element. The ducts are enlarged and often flattened and are lined by an insignificant outer myoepithelial layer and an inner, more prominent epithelial layer. The epithelial layer frequently shows mild hyperplasia with luminal tufting or more prominent micropapillary change. The stroma may be loose, myxoid and abundant or acellular and fibrous.

Management
Pubertal gynecomastia does not usually require any treatment since 80% resolve spontaneously. Occasionally, for cosmetic reasons, subcutaneous mastectomy is indicated. Alternatives to excisional surgery include liposuction.

Correction of other associated conditions that alter the balance between estrogen and androgens may result in some regression in the early stages. Since the majority of patients improve spontaneously, therapy should be targeted to patients with long-standing gynecomastia. Medical therapy is the first line of treatment in patients with moderate to severe symptoms. Androgens, antiestrogens and aromatase inhibitors have all been tested in patients with gynecomastia. The scientific evidence is in favor of tamoxifen 20 mg daily for 3 months.

Surgical intervention in the form of subcutaneous mastectomy or liposuction may be necessary for patients in whom other measures have failed.

A.D. Purushotham, P. Britton and L. Bobrow
A prospective study of benign breast disease and the risk of breast cancer. JAMA 2002

References