Chapter 19 GYNECOMASTIA
Causes of Gynecomastia
Key Physical Findings
Differentiate pseudogynecomastia (fatty tissue) from true gynecomastia
Evidence of systemic disease, such as thyrotoxicosis, liver disease, or adrenal disease
Suggested Work-up
| Thyroid-stimulating hormone (TSH) | To evaluate for hyperthyroidism |
| Luteinizing hormone | See Figure 19-1 |
| Testosterone level | See Figure 19-1 |
| Estradiol level | To evaluate for testicular Leydig-cell tumor or feminizing adrenocortical neoplasm |
| Human chorionic gonadotropin (hCG) level | To evaluate for testicular germ cell tumor, extragonadal germ cell tumor, or hCG-secreting nontrophoblastic neoplasm |
| See Figure 19-1 | |
| Serum electrolytes | To evaluate for adrenal disease |
| Blood urea nitrogen (BUN) and creatinine | To evaluate for renal disease |
| Liver function tests | To evaluate for liver disease |
Additional Work-up
| Prolactin level | If gynecomastia is associated with galactorrhea to evaluate for prolactinoma |
| HIV test | If HIV infection is suspected or the patient has risk factors for infection |
| Testicular ultrasonongraphy | If testicular examination is abnormal or if estradiol is increased with a decreased or normal luteinizing hormone |
| Adrenal computed tomography (CT) or magnetic resonance imaging (MRI) | If adrenal neoplasm is suspected |
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