Breast

Other benign tumors

Ductal adenoma



Last author update: 2 February 2024
Last staff update: 2 February 2024

Copyright: 2002-2024, PathologyOutlines.com, Inc.

PubMed Search: Ductal adenoma

Susanne M. Crespo-Ramos, M.D.
Anna Biernacka, M.D., Ph.D.
Page views in 2023: 6,556
Page views in 2024 to date: 1,814
Cite this page: Crespo-Ramos SM, Biernacka A. Ductal adenoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/breastductaladenoma.html. Accessed March 19th, 2024.
Definition / general
  • Benign tumor composed of distorted glands in a sclerotic stroma surrounded by a fibrous capsule
  • First described by Azzopardi and Salm in 1984 (J Pathol 1984;144:15)
Essential features
  • Rare, benign adenomatous lesion of medium and small sized ducts in the peripheral breast
  • Well circumscribed, single (occasionally multinodular), solid proliferation of tubules set within a fibrous stroma and surrounded by a thickened fibroelastotic wall
  • Considered a highly sclerotic variant of intraductal papilloma with obliterated papillary growth
  • May show calcifications, hemorrhage, infarction, squamous or apocrine metaplasia, epithelial hyperplasia, myxoid or chondroid change, central scar or pseudoinfiltrative pattern (exclude invasion by showing intact myoepithelial cells; e.g., p63, SMMHC)
  • Excision is curative
Terminology
  • Not recommended: sclerosing papilloma
ICD coding
  • ICD-O: 8503/0 - duct adenoma, NOS
  • ICD-10
    • D24 - benign neoplasm of breast
    • D24.1 - benign neoplasm of right breast
    • D24.2 - benign neoplasm of left breast
    • D24.9 - benign neoplasm of unspecified breast
  • ICD-11: 2F30.2 & XH4LZ4 - intraductal papilloma of breast & intraductal papilloma
Epidemiology
Sites
Pathophysiology
  • Most likely, it originates from intraductal papilloma in small and medium sized ducts (J Pathol 1984;144:15, Hum Pathol 1989;20:903)
  • Due to the stromal repair process, papilloma undergoes sclerosis, resulting in loss of the arborizing papillary architecture
  • Another theory implicates a direct expansion of hyperplastic processes such as sclerosing adenosis into small and medium sized ducts or coexistent intraductal papilloma (Hum Pathol 1989;20:903)
  • Stromal degenerative changes may occur in the center, similar to radial scar
Etiology
Clinical features
Diagnosis
  • May resemble carcinoma on clinical examination, imaging, needle aspiration cytology and core biopsy (J Pathol 1984;144:15, Breast Cancer 2006;13:354)
  • Excision is often recommended due to histological and radiological mimicry of carcinoma
Radiology description
  • Imaging features may suggest papilloma, fibroadenoma or mimic carcinoma (Breast Cancer 2006;13:354)
  • Mammography shows well to ill defined mass with or without calcification
  • Ultrasonography shows a well defined, round hypoechoic nodule with shadowing and posterior enhancement
  • On contrast enhanced MRI, margins are smooth despite histologic pseudoinvasion (Breast Cancer 2016;23:597)
Radiology images

Contributed by Thomas Lienhoop, M.D.
Screening mammogram Screening mammogram

Screening mammogram

Diagnostic ultrasound Diagnostic ultrasound

Diagnostic ultrasound

Prognostic factors
  • Benign, with no increased risk for recurrence or malignant transformation after complete excision (Hum Pathol 1989;20:903)
  • 1 case reported in the literature associated with malignant transformation to apocrine and epithelial myoepithelial carcinoma (Malays J Pathol 2015;37:281)
Case reports
Treatment
Gross description
  • Ranges in size from 0.5 to 5.0 cm (average: 0.85 cm) (J Pathol 1984;144:15)
  • Solid white nodule with lobulated and granular cut surface and central gray softening
  • Gritty texture and elastic streaks mimic carcinoma
  • Solitary or occasionally multiple nodules in close proximity
  • Multinodular tumors due to the involvement of different parts of the same ductal system (Hum Pathol 1989;20:903)
Microscopic (histologic) description
  • Well circumscribed, intraductal, solitary or multinodular (rare) lesion, surrounded by a thickened concentric fibroelastotic wall (J Pathol 1984;144:15)
  • Adenomatous portion has solid architecture and consists of proliferating tubules set in a fibrous stroma
  • No arborizing papillary fronds (as seen in intraductal papilloma) or myoepithelial hyperplasia (as seen in adenomyoepithelioma)
  • Glands range from round to oval, elongated to branched
  • Epithelial and myoepithelial cell types are present (the latter may be inconspicuous)
  • Ductal cells are cuboidal, columnar or spindled, with no atypia and only rare mitoses
  • Cystic gland dilatation, epithelial hyperplasia, apocrine or squamous metaplasia, eosinophilic secretions or laminated calcifications may be present (Hum Pathol 1989;20:903)
  • Stroma is usually fibrous, modest in amount and may show myxoid change, prominent hyalinization and rarely cartilaginous metaplasia (Pathol Int 2002;52:239)
  • Compression of glands similar to sclerosing adenosis is frequently seen (Hum Pathol 1989;20:903)
  • Distortion and entrapment of glands in the sclerotic wall may result in a pseudoinfiltrative pattern
  • Glandular proliferation may protrude into surrounding tissue, pushing beyond ductal confines (pushing borders) (J Pathol 1984;144:15)
  • Duct wall may contain dystrophic calcifications; periductal chronic inflammation may be seen (Hum Pathol 1989;20:903)
  • In stellate form, central fibroelastosis with entrapped epithelial tubules and peripheral dilated glandular elements resembles radial scar (J Pathol 1984;144:15)
  • Secondary changes such as hemorrhage or infarction may occur (Breast Cancer 2006;13:354)
Microscopic (histologic) images

Contributed by Susanne M. Crespo-Ramos, M.D., Anna Biernacka, M.D., Ph.D. and AFIP
Epithelial cell nests and glands

Epithelial cell nests and glands

Compressed glands

Compressed glands

Well circumscribed adenomatous nodule

Well circumscribed adenomatous nodule

Duct wall / capsule

Duct wall / capsule

Duct distention and pseudoinvasion

Duct distention and pseudoinvasion

Pseudoinfiltrative and pushing borders

Pseudoinfiltrative and pushing borders


Glands and stroma

Glands and stroma

Epithelial and myoepithelial cells

Epithelial and myoepithelial cells

Eosinophilic secretions

Eosinophilic secretions

Usual ductal hyperplasia

Usual ductal hyperplasia

Missing Image

Central fibrosis, peripheral bland ducts

Missing Image

Nodular lesion, primarily spindle cells


Missing Image

Spindle cells with residual ducts

Missing Image

Spindled myoepithelial cells around peripheral duct

Missing Image

Ducts lined by apocrine cells

Smooth muscle myosin

Smooth muscle myosin

p63

p63

Cytokeratin 5/6

Cytokeratin 5/6

Cytology description
  • Highly cellular aspirates (Diagn Cytopathol 1994;10:143, Diagn Cytopathol 1995;13:252)
  • Numerous branching flat sheets of regularly spaced cohesive ductal cells
  • Large fragments of purple stroma in tight association with epithelial cells, forming finger-like hyaline structures or globules between cells
  • Background of single cells, naked nuclei, histiocytes and apocrine cells
  • Nuclei are round / oval with bland chromatin
  • Cytoplasm with small punched out vacuoles
Positive stains
Negative stains
Molecular / cytogenetics description
  • 9 cases of ductal adenoma that have been studied using next generation sequencing showed recurrent missense mutations affecting AKT1, GNAS and PIK3CA genes (Genes Chromosomes Cancer 2017;56:11)
  • Given the high frequency of AKT1 mutations in breast papillomas, these data support the notion that ductal adenomas are closely related to or are, in fact, intraductal papillomas that have undergone sclerosis (Mod Pathol 2010;23:27)
Sample pathology report
  • Right breast, excisional biopsy:
    • Benign intraductal glandular proliferation with sclerotic stroma consistent with ductal adenoma (see comment)
    • Comment: The specimen shows a solid nodule with a prominent component of glands and stromal sclerosis, surrounded by a thickened hyalinized wall. Immunohistochemical studies show a heterogenous staining pattern for cytokeratin 5/6 and estrogen receptor and focally attenuated yet retained myoepithelial cells highlighted by smooth myosin heavy chain and p63. The overall findings are consistent with ductal adenoma, which is a benign tumor with features similar to sclerosing intraductal papilloma.
Differential diagnosis
  • Intraductal papilloma:
    • Proliferative epithelial cells with fibrovascular cores (papillary architecture)
    • Can arise from small to medium sized peripheral ducts but also from larger subareolar ducts
  • Tubular adenoma:
    • Closely packed round and oval tubules with sparse intervening stroma
    • Histogenetically related to the pericanalicular subset of fibroadenomas
  • Fibroadenoma:
    • Biphasic tumor; proliferation of both glandular epithelial and stromal components
Board review style question #1

A 65 year old woman had a right breast lumpectomy showing a well circumscribed firm nodule with a lobulated and granular cut surface. Histologic features are shown in the image. Which of the following is the correct diagnosis?

  1. Ductal adenoma
  2. Fibroadenoma
  3. Intraductal papilloma
  4. Invasive ductal carcinoma
  5. Tubular adenoma
Board review style answer #1
A. Ductal adenoma. Ductal adenoma is a benign, well circumscribed adenomatous lesion in a duct surrounded by a densely thickened fibroelastotic wall. It has a solid architecture with an intermixture of tubules and sclerotic stroma and lacks arborizing papillary fronds. Answer C is incorrect because intraductal papillomas display arborizing papillary fronds. Answer D is incorrect because although gland distortion by sclerosis may mimic an infiltrative pattern the myoepithelium is retained in this specimen. Answers B and E are incorrect because fibroadenomas and tubular adenomas arise from terminal duct lobular units rather than duct lumens and lack a prominent capsule. They are histogenetically related biphasic lesions, with the stromal component dominating fibroadenoma and florid adenosis-like epithelial proliferation dominating tubular adenoma.

Comment Here

Reference: Ductal adenoma
Back to top
Image 01 Image 02