Summary
Definition
Gynaecomastia is the benign enlargement of the male breast with firm tissue extending concentrically beyond the nipple. Histologically, gynaecomastia is the benign proliferation of breast ducts and duct epithelial hyperplasia accompanied by varying amounts of inflammation, oedema, stroma, and fibrosis. Male breast enlargement entirely due to adipose tissue is called pseudo-gynaecomastia.
[Figure caption and citation for the preceding image starts]:
Histology: gynaecomastia; clusters of ducts, halos of oedema, fibrous background; 5X magnification
From the collection of Catherine B. Niewoehner, MD
[Citation ends].
History and exam
Key diagnostic factors
- presence of risk factors
- palpable breast tissue
- newborn age
- pubertal age
- older adult age
- accidental medication exposure in children
- chemical substance abuse
- acne in adult males
- obesity
- breast pain
- small or soft testicles
Other diagnostic factors
- erectile dysfunction or decreased libido
- nutritional supplements
- past history of abnormal sexual differentiation
- delayed secondary sex characteristics
- precocious puberty
- weight loss and malnutrition
- signs or symptoms of hypothalamic or pituitary disease
- signs or symptoms of liver failure (e.g., jaundice, ascites, spiders)
- signs or symptoms of hyperthyroidism (e.g., heat intolerance, weight loss, goitre)
- decreased body hair
- painless or enlarging testicular mass
- diminished strength or muscle atrophy
Risk factors
- anabolic steroid usage
- occupational exposure to embalming fluid or oral contraceptives
- contact with environmental phyto-oestrogens or phthalates
- prostate cancer
- gender identity disorder
- hyperthyroidism
- renal failure
- cirrhosis
- drugs that reduce testosterone synthesis
- drugs that impair testosterone action
- drugs that increase oestrogen levels or stimulate oestrogen receptors
- drugs with complex or unknown mechanisms
Diagnostic investigations
1st investigations to order
- serum TSH
- serum creatinine
- serum LFTs
- core biopsy of breast (if cancer suspected)
Investigations to consider
- serum total testosterone
- serum LH
- serum estradiol
- serum sex hormone binding globulin (SHBG)
- serum free testosterone
- serum beta hCG
- serum dehydroepiandrosterone sulphate (DHEAS)
- serum prolactin
- mammogram
- breast ultrasound
Treatment algorithm
Contributors
Authors VIEW ALL
Professor of Medicine
University of Minnesota
Minneapolis
MN
Disclosures
CBN is an author of a number of references cited in this monograph.
Peer reviewers VIEW ALL
Professor of Pediatrics
Rumsey Chair of Pediatric Endocrinology
University of California
Sacramento
CA
Disclosures
DS declares that he has no competing interests.
Professor of Medicine and Head of Endocrinology
Stony Brook University
Stony Brook
NY
Disclosures
HC is an author of a reference cited in this monograph.
Professor and Chairman
Department of Medicine
Cedars-Sinai Medical Center
Los Angeles
CA
Disclosures
GB declares that he has no competing interests.
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