Gynecomastia - Diagnosis

Diagnosis

To reach a diagnosis of gynecomastia, other causes of male breast enlargement such as mastitis, breast cancer, pseudogynecomastia, lipoma, sebaceous cyst, dermoid cyst, hematoma, metastasis, ductal ectasia, fat necrosis, or a hamartoma are typically excluded. Ultrasonography has supplanted mammography as the method of choice for radiologic examination of male breast tissue in the diagnosis of gynecomastia. Gynecomastia usually presents with bilateral involvement of the breast tissue but may occur unilaterally as well. Histological examination of tissue attained by fine needle aspiration cytology may demonstrate dilated ducts with periductal fibrosis, increased subareolar fat, and hyalinization of the stroma.

Gynecomastia should also be distinguished from muscle hypertrophy of the pectoralis muscles. When surgery is performed, the gland is routinely sent to the lab to confirm the presence of gynecomastia and to check for tumors under a microscope. The utility of pathologic examination of breast tissue removed from male adolescent gynecomastia patients has recently been questioned due to the rarity of breast cancer in this population.

A review of the medications or illegal substances an individual takes may reveal the cause of gynecomastia. Recommended laboratory investigations to find the underlying cause of gynecomastia include tests for aspartate transaminase and alanine transaminase to rule out liver pathology, serum creatinine to evaluate if kidney damage is present, and thyroid-stimulating hormone levels to evaluate for hyperthyroidism. Medical imaging may be indicated in a subset of patients to rule out adrenal tumors, pituitary tumors, or male breast cancer. Additional tests that may be considered are markers of testicular, adrenal, or other tumors such as urinary 17-ketosteroid, serum beta human chorionic gonadotropin, or serum dehydroepiandrosterone. Serum testosterone levels (free and total), estradiol, luteinizing hormone, and follicle stimulating hormone may also be evaluated to determine if hypogonadism may be the cause of gynecomastia.