Other benign tumors

Apocrine adenoma

Last author update: 1 January 2016
Last staff update: 16 December 2021

Copyright: 2002-2024,, Inc.

PubMed Search: Breast [title] apocrine adenoma

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Apocrine adenoma . website. Accessed February 23rd, 2024.
Definition / general
  • Adenoma with apocrine cytology throughout
  • Rare adenoma that is:
    • Composed exclusively of benign apocrine cells (homogeneous)
    • Sharply demarcated from surrounding breast tissue
    • Contains only epithelial proliferative elements
    • Has minimal supportive stroma
Essential features
  • Nodular mass composed exclusively of apocrine cells without cytological atypia
  • Sharply demarcated from adjacent breast tissue and has minimal stromal component if any
  • Considered benign, excision is curative
  • Cytological atypia, necrosis and invasive features suggest atypical hyperplasia / apocrine malignancy (DCIS / invasive), recommend careful evaluation of the entire lesion
  • Pure breast adenomas with apocrine differentiation were first described by Hertel et al. in 1976 (Cancer 1976;37:2891)
  • May represent nodular sclerosing adenosis with apocrine differentiation
Clinical features
  • Can present as a mass
Prognostic factors
  • Generally accepted to be benign, however, the number of cases reported is not sufficient to determine the level of risk associated (J Clin Pathol 2007;60:1313)
Case reports
  • Complete excision is curative
Microscopic (histologic) description
  • By definition, composed exclusively of benign apocrine cells (homogeneous), sharply demarcated from surrounding breast tissue, containing only epithelial proliferative elements, with minimal supportive stroma
  • Localized nodular focus of tubular, papillary and cystic apocrine metaplasia; benign glands have abundant granular eosinophilic cytoplasm, apical luminal blebs and decapitation secretion
  • May contain calcifications (Pathology 2001;33:149)
Cytology description
  • Can be cuboidal or flattened, two distinct types seen:
    • Cytoplasm granular and strongly eosinophilic, supranuclear vacuole containing yellow brown pigment (rich in iron / hemosiderin)
      • Globoid and pale nuclei with 1 - 2 prominent nucleoli (nuclei may become hyperchromatic in flattened epithelium as in tension apocrine cysts)
    • Cytoplasm distinctly foamy with small vacuoles that may coalesce and show lipofuscin pigment in cytoplasm
      • Central nuclei with 1 - 2 prominent nucleoli
  • Recommend caution to exclude apocrine DCIS or invasive apocrine carcinoma if necrosis / atypia / mitosis present
Positive stains
  • PAS (with diastase), EMA, CK8 / 18, AR (androgen receptor), GCDFP15, GCDFP24 (apolipoprotein D), GCDFP44 (zinc alpha2 glycoprotein)
Negative stains
Differential diagnosis
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