Breast malignant, males, children
Male tumors
Gynecomastia in males

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 22 December 2016, last major update August 2012

Copyright: (c) 2001-2016,, Inc.

PubMed Search: male gynecomastia
Cite this page: Gynecomastia in males. website. Accessed November 22nd, 2017.
Definition / general
  • Enlargement of male breast due to hypertrophy and hyperplasia of glands and stroma
  • Multifactorial etiology: physiological (puberty or aging), endocrine tumors, endocrine dysfunctions, nonendocrine diseases, drug induced, idiopathic
Clinical features
Prognostic factors
  • May recur
Case reports
Clinical images

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Spironolactone induced

Gross description
  • Button or disk-like subareolar enlargement
  • Oval, elastic and with well circumscribed borders
  • Unilateral (more common) or bilateral
  • Firm, gray-white cut surface
Microscopic (histologic) description
  • Proliferation of ducts without lobules
  • Dense, periductal stromal fibrosis or edema with micropapillary hyperplasia and mild lymphocytic infiltrate
  • Epithelium may be surrounded by prominent swollen stroma giving "halo" effect
  • Over time, less hyperplasia and more stromal fibrosis
  • May have pseudoangiomatous stromal hyperplasia, focal squamous metaplasia (Arch Pathol Lab Med 1986;110:971)
Microscopic (histologic) images

Images hosted on PathOut server:

Periductal stromal
edema with
mild epithelial

Solid form with
microlumina, different
cell types in central
and peripheral duct

Post-estrogen treatment for prostatic carcinoma

With atypical duct hyperplasia

Micropapillary pattern
of slender strands of cells
with hyperchromatic nuclei (AFIP)

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Cytology images

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Clusters of bland, cohesive epithelial cells

Positive stains
  • ER and PR are associated with Kleinfelter's syndrome
  • PSA is associated with antiandrogen therapy (but PSAP negative)
Electron microscopy description
  • Proliferation of epithelial and myoepithelial cells, intracytoplasmic lumina and squamous metaplasia
  • Stroma shows fibroblasts, myofibroblasts and some pericytes (Arch Pathol Lab Med 1979;103:624)