Other benign tumors

Ductal adenoma

Last author update: 1 November 2015
Last staff update: 3 September 2021

Copyright: 2002-2022,, Inc.

PubMed Search: Ductal adenoma [title] breast

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Ductal adenoma . website. Accessed July 6th, 2022.
Definition / general
Essential features
  • Well circumscribed benign intraductal proliferation of tubules (no papillary component)
  • May show calcification, hemorrhage, infarction, squamous or apocrine metaplasia or myxoid change
  • May show pseudoinfiltrative pattern (exclude invasion by showing intact myoepithelial marker staining, e.g. p63, SMMA)
  • Excision is curative
  • Also called sclerosing papilloma
Clinical features
  • Presents as palpable lump or mammographic abnormality
  • May resemble carcinoma at imaging, frozen or permanent section (Breast Cancer 2006;13:354)
Radiology description
  • Mammography shows well to ill defined mass with / without calcification
Case reports
  • Excision is curative
Gross description
  • Single or multiple rounded lesions
  • Gritty texture and elastic streaks mimic carcinoma
Microscopic (histologic) description
  • Well circumscribed, bounded by dense fibrous wall of medium to large duct from which it arises
  • Composed of proliferating epithelial tubules but no papillary component (or it would be a papilloma)
  • Has both epithelial and myoepithelial cell types
  • May have pseudoinfiltrative pattern due to compressed tubules, which resembles invasion in a core biopsy
  • Also focal dilated tubules, epithelial hyperplasia, cysts, squamous or apocrine metaplasia, myxoid change, calcification
Microscopic (histologic) images

AFIP images
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Central fibrosis, peripheral bland ducts

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Nodular lesion, primarily spindle cells

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Spindle cells with residual ducts

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Spindled myoepithelial cells around peripheral duct

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Ducts lined by apocrine cells

Images hosted on other servers:
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Ductal adenoma, partially sclerosed

Cytology description
  • May resemble lactating adenoma, intraductal papilloma or carcinoma
  • Highly cellular with monolayered sheets of ductal cells with cytoplasmic vacuoles that are small and punched out
  • Numerous large fragments of purple stroma are adjacent to epithelial cells, forming finger-like hyaline structures or globules between cells
  • Nuclei are round / oval with bland chromatin
  • Occasional cells have enlarged nuclei with prominent nucleoli
  • Also naked oval nuclei (Diagn Cytopathol 1994;10:143, Diagn Cytopathol 1995;13:252)
Positive stains
Negative stains
Differential diagnosis
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