Differential Diagnosis for Gynecomastia
Single Most Likely Diagnosis
- Physiologic gynecomastia: This is the most common cause of gynecomastia, particularly in neonates, adolescents, and older adults. It occurs due to the imbalance between estrogen and androgen levels, which can happen during these life stages due to natural hormonal fluctuations.
Other Likely Diagnoses
- Medication-induced gynecomastia: Various medications can cause gynecomastia as a side effect, including spironolactone, cimetidine, and certain antidepressants and antipsychotics. The likelihood of this diagnosis depends on the patient's medication history.
- Hypogonadism: Conditions that lead to low testosterone levels, such as Klinefelter syndrome or pituitary gland problems, can cause gynecomastia due to the relative increase in estrogen levels compared to androgen levels.
- Thyroid disorders: Both hyperthyroidism and hypothyroidism can lead to gynecomastia, though the mechanisms are not fully understood. Thyroid disorders can affect hormone metabolism and balance.
Do Not Miss Diagnoses
- Testicular cancer: Though rare, testicular cancer (especially Leydig cell and Sertoli cell tumors) can produce estrogen, leading to gynecomastia. Early detection is crucial for effective treatment.
- Pituitary tumors: Tumors of the pituitary gland, such as prolactinomas, can disrupt normal hormone production, including an increase in prolactin, which can indirectly affect the balance between estrogen and testosterone.
- Adrenal tumors: Rarely, tumors of the adrenal gland can produce excess estrogen, leading to gynecomastia.
Rare Diagnoses
- Congenital adrenal hyperplasia: This is a group of inherited disorders that affect the adrenal glands, leading to hormone imbalances. Some forms can result in an overproduction of androgens, but in the context of gynecomastia, it's more about the imbalance rather than the absolute levels.
- Aromatase excess syndrome: A rare condition where there's an overproduction of aromatase, the enzyme that converts androgens to estrogens, leading to an imbalance favoring estrogen and potentially causing gynecomastia.
- Familial gynecomastia: Some families may have a genetic predisposition to gynecomastia, often due to mutations affecting androgen receptors or other components of the hormonal pathway.