No abstract

Gynaecomastia (enlargement of the male breast tissue) is a common finding in the general population. Most cases of gynaecomastia are benign and of cosmetic, rather than clinical, importance. However, the condition might cause local pain and tenderness, could occasionally be the result of a serious underlying illness or a medication, or be inherited. Breast cancer in men is much less common than benign gynaecomastia, and the two conditions can usually be distinguished by a careful physical examination. Estrogens are known to stimulate the growth of breast tissue, whereas androgens inhibit it; most cases of gynaecomastia result from deficient androgen action or excessive estrogen action in the breast tissue. In some cases, such as pubertal gynaecomastia, the breast enlargement resolves spontaneously. In other situations, more active treatment might be required to correct an underlying condition (such as hyperthyroidism or a benign Leydig cell tumour of the testis) or medications that could cause breast enlargement (such as spironolactone) might need to be discontinued. For men with hypogonadism, administration of androgens might be helpful, as might antiestrogen therapy in men with endogenous overproduction of estrogens. Surgery to remove the enlarged breast tissue might be necessary when gynaecomastia does not resolve spontaneously or with medical therapy.

Results of this study indicate that nicotine from cigarette smoking increases circulating levels of cortisol, growth hormone, and prolactin in male chronic smokers. Previous studies have not addressed the question of whether the stimulus for smoking-related hormone release is the 'stress' of smoking or a pharmacologic action of nicotine and other tobacco substrates. Nicotine exposure is controlled in this study by allowing each subject to smoke only two 2.0 mg nicotine cigarettes during one experimental session and two 0.2 mg nicotine cigarettes in another session. Plasma levels of cortisol, growth hormone, and prolactin for the higher nicotine session were found to be significantly elevated over those for the low-nicotine session, indicating that nicotine itself plays a predominate role in smoking-induced hormone increases. All hormone levels for the 2.0 mg nicotine session had not returned to baseline 60 min after smoking.

Gynecomastia is common, being present in 30% to 50% of healthy men. A general medical history and careful physical examination with particular attention to features suggestive of breast cancer often suffice for evaluation in patients without symptoms or those with incidentally discovered breast enlargement. Men with recent-onset gynecomastia or mastodynia need a more detailed evaluation, including selected laboratory tests to search for an underlying cause. Treatment depends on the cause and may include observation, withdrawal of an offending drug, therapy of an underlying disease, giving androgen or antiestrogen drugs, or plastic surgery. s KEY POINTS Gynecomastia is probably not associated with an increased risk of breast cancer, except in Klinefelter syndrome. Most cases of gynecomastia result from an imbalance between estrogenic (stimulatory) and androgenic (inhibitory) effects on the breast. Drug-induced gynecomastia accounts for 20% to 25% of cases. Even with detailed evaluation, there is no identifiable cause in about 25% of cases. G This paper discusses therapies that are experimental or are not approved by the US Food and Drug Administration for the use under discussion.