Gynecomastia

Definition

• Mass in the male breast formed by increased ducts and prominent stroma

Alternate/Historical Names

• Gynecomasty

Diagnostic Criteria

• Increased ducts and prominent stroma
• May be well or poorly circumscribed
• Early phase
  • Intraductal epithelial proliferation
    • Both epithelial and myoepithelial
    • May be micropapillary or cribriform
    • May be atypical
      • No evidence of increased risk of carcinoma
      • No studies have examined the significance of atypical hyperplasia and carcinoma in situ in gynecomastia
        • In the absence of such studies we use those derived for the female breast
    • May show squamous metaplasia
    • Apocrine metaplasia frequent
  • Periductal stroma typically edematous
    • May show increased cellularity
• Late phase
  • Less epithelial proliferation
    • May be atrophic with dilated ducts
  • Periductal fibrosis
• Lobule formation infrequently seen
• Occasional periductal lympho-plasmacytic infiltrate
• Pseudoangiomatous stromal hyperplasia in about 25% of cases
• Histology independent of cause

Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting:: May 27, 2006

Supplemental studies

Immunohistology

• Estrogen and progesterone receptors positive in epithelial cells in most cases
• Prostate specific antigen (PSA) may be focally strongly reactive in about 25% of cases
• Prostatic acid phosphatase is negative

Differential Diagnosis

Diabetic Mastopathy / Lymphocytic Mastitis	Gynecomastia
Prominent perivascular, periductal, perilobular cuffing by B lymphocytes	Occasional perivascular lymphocytes
Keloidal like stromal fibrosis	No keloidal fibrosis
Prominent epithelioid fibroblasts	Fibroblasts not epithelioid
History of diabetes	No increased incidence of diabetes

Diabetic mastopathy may rarely occur in males

Clinical

• Occurs from puberty to old age with peaks at both ends of the range
  • Rarely described in infants
• May be unilateral or bilateral
• Rarely regresses spontaneously
• Most cases idiopathic
• Associated medical conditions
  • Cirrhosis
  • Germ cell tumors
  • Hyperthyroidism
  • Hypogonadism
  • Lung carcinoma
• Associated drugs
  • Androgens
  • Antiretrovirals
  • Cimetidine
  • Digitalis
  • Estrogens
  • Marijuana
  • Spironolactone
  • Tricyclic antidepressants

Lists

Biphasic lesions of the breast

• Adenomyoepithelioma
• Fibroadenoma
• Gynecomastia
• Hamartoma
• Juvenile Fibroadenoma
• Metaplastic Carcinoma
• Phyllodes Tumor
• Pleomorphic Adenoma
• Pubertal Macromastia

Bibliography

• Rosen PP, Oberman HA. Tumors of the Mammary Gland, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 7, 1993
• Harigopal M, Murray MP, Rosen PP, Shin SJ. Prepubertal gynecomastia with lobular differentiation. Breast J. 2005 Jan-Feb;11(1):48-51.
• Gatalica Z, Norris BA, Kovatich AJ. Immunohistochemical localization of prostate-specific antigen in ductal epithelium of male breast. Potential diagnostic pitfall in patients with gynecomastia. Appl Immunohistochem Mol Morphol. 2000 Jun;8(2):158-61.
• Bannayan GA, Hajdu SI. Gynecomastia: clinicopathologic study of 351 cases. Am J Clin Pathol. 1972 Apr;57(4):431-7.
• Andersen JA, Gram JB. Gynecomasty: histological aspects in a surgical material. Acta Pathol Microbiol Immunol Scand [A]. 1982 May;90(3):185-90.
• Milanezi MF, Saggioro FP, Zanati SG, Bazan R, Schmitt FC. Pseudoangiomatous hyperplasia of mammary stroma associated with gynaecomastia. J Clin Pathol. 1998 Mar;51(3):204-6.
• Sasano H, Kimura M, Shizawa S, Kimura N, Nagura H. Aromatase and steroid receptors in gynecomastia and male breast carcinoma: an immunohistochemical study. J Clin Endocrinol Metab. 1996 Aug;81(8):3063-7.
• Andersen J, Orntoft TF, Andersen JA, Poulsen HS. Gynecomastia. Immunohistochemical demonstration of estrogen receptors. Acta Pathol Microbiol Immunol Scand [A]. 1987 Sep;95(5):263-7