Lab Studies

History and physical examinations are key elements used when considering the diagnosis of gynecomastia.12 Longstanding stable cases in an adult do not require blood tests other than those that would be required for an outpatient surgery. For routine outpatient surgery in healthy individuals aged less than 40 y, the authors do not require any laboratory testing prior to routine surgery.

Blood work should include liver function tests and assays for follicle-stimulating hormone, luteinizing hormone, human chorionic gonadotropin, thyroid-stimulating hormone, thyroxine, estrogen, estradiol, and testosterone levels in children and in individuals with progressive disease.

The coauthor requires a normal prothrombin time/partial thromboplastin time (PT/PTT) before surgery is performed. If a patient has a history of bleeding with wisdom tooth extraction or adenoid surgery, further investigation should be performed to rule out medical bleeding such as von Willebrand disease.

See the image to the right.

A sex chromatin study should be performed to exclude Klinefelter syndrome when appropriate.

Elevated estrogen and 17-ketosteroid levels in urine indicate the presence of a feminizing adrenal tumor.

Imaging Studies

If indicated by the patient's history, physical examination, and laboratory results, preoperative workup may include an ultrasound examination of the testes and breasts, computed tomography scan of adrenal glands, magnetic resonance imaging of sella turcica, and mammography when appropriate.

Other Tests

Excisional biopsy or fine-needle aspiration of breast tissue should be performed if a breast tumor is suspected.

Excised tissue should be sent for histological examination to exclude malignancy in appropriate cases. Approximately 1% of all primary breast tumors are reportedly found in men, and breast cancer accounts for 0.7% of all male cancers. As previously mentioned, unilateral cases with rapid progression should be viewed with suspicion.

Diagnostic Procedures

Histologic Findings

Gynecomastia has 3 recognized pathological patterns, as follows:

  • The first type, the florid type, is characterized by an increase in the number and length of ducts, proliferation of ductal epithelium, periductal edema, a highly cellular fibroblastic stroma and hypervascularity, and the formation of pseudolobules. The florid type is the most common in patients with gynecomastia of less than 4 months' duration.
  • The second type, the fibrous type, is characterized by dilated ducts with minimal proliferation of epithelium, an absence of periductal edema, and an almost acellular fibrous stroma without adipose tissue. The fibrous type is the most common in patients with gynecomastia that lasts for 4-12 months.
  • The third type, the intermediate type, is an overlapping pattern of both the florid and the fibrous types.


Idiopathic gynecomastia is a benign condition.

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