Breast
Fibroepithelial tumors
Fibroadenomatoid change

Editorial Board Member: Gary Tozbikian, M.D.
Editor-in-Chief: Debra Zynger, M.D.
Melissa Alexander, M.D., Ph.D.

Topic Completed: 5 October 2020

Minor changes: 5 October 2020

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PubMed Search: fibroadenomatous change OR fibroadenomatoid change

Melissa Alexander, M.D., Ph.D.
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Cite this page: Alexander M. Fibroadenomatoid change. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastfibroadenomatoidchange.html. Accessed October 20th, 2020.
Definition / general
  • Benign, often incidental finding in a background of fibrocystic changes
  • Lesion with features resembling a fibroadenoma but lacking sharp circumscription
Essential features
  • Proliferation of intralobular stroma with the formation of stromal nodularity that often appears to blend in with the surrounding breast tissue
  • Morphologically reminiscent of a fibroadenoma but not forming a well circumscribed mass
  • May represent an incipient fibroadenoma
  • Often multifocal and surrounded by fibrocystic changes
Terminology
  • Also known as fibroadenomatous change, fibroadenomatoid hyperplasia, fibroadenomatoid mastopathy, fibroadenomatosis, sclerosing lobular hyperplasia
  • Less frequently referred to as mixed lesion, reflecting the common association of fibroadenomatoid change and fibrocystic changes
ICD coding
  • ICD-10: N60.2 - fibroadenosis of breast
Epidemiology
Sites
Pathophysiology
  • Proliferation of intralobular stroma
  • May represent a stage in the evolution of a fibroadenoma, produced by the coalescence of fibroadenomatoid nodules
  • Reference: Hum Pathol 1984;15:336
Etiology
  • Unknown; possibly due to or influenced by reproductive hormones, similar to fibroadenoma
Clinical features
  • May be detected by imaging modalities (see Radiology below), as a palpable mass or incidentally in breast tissue sampled for a different lesion
Diagnosis
Radiology description
  • Hypoechoic mass
  • Asymmetric increased density
  • Suspicious granular clustered microcalcifications (more frequent in women > 50 years old)
  • No suspicious findings in patient with palpable mass
  • Imaging findings in one study of fibroadenomatoid hyperplasia showed 53% were well defined mass
    • 33% had normal mammographic findings
    • 13% had an asymmetric density
    • 1% with mammographic calcifications
  • References: AJR Am J Roentgenol 1995;165:291, AJR Am J Roentgenol 1998;171:1331, Hum Pathol 1984;15:336
Radiology images

Images hosted on other servers:
Well circumscribed nodule

Well circumscribed nodule

Suspicious granular microcalcifications

Suspicious granular microcalcifications

Prognostic factors
  • No increased risk of malignancy
Case reports
Treatment
  • No treatment required
Gross description
  • Lesion appears dense and poorly circumscribed on cut section
  • Difficult to distinguish from fibrocystic changes by gross examination
  • Reference: Malays J Pathol 1991;13:101
Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Melissa Alexander, M.D., Ph.D.
Edges blending with surrounding Edges blending with surrounding

Edges blending with surrounding

Vague stromal nodularity

Vague stromal nodularity

Poorly circumscribed

Poorly circumscribed

Background fibrocystic change

Background fibrocystic change

Multiple nodules

Multiple nodules


Multiple nodules

Multiple nodules

Loose stroma versus dense hyalinized

Loose stroma versus dense hyalinized

Dense stroma

Dense stroma

Loose versus dense nodules

Loose versus dense nodules

Loose stroma, compressed glands

Loose stroma, compressed glands

Fibroadenomatoid nodule, compressed glands

Fibroadenomatoid nodule, compressed glands

Cytology description
  • Elements similar to fibroadenoma, including stromal fragments; however, lacking other elements of fibroadenoma including branching antler horn epithelial clusters (Cytojournal 2006;3:8, Acta Cytol 2001;45:765)
Sample pathology report
  • Breast, right, core biopsy:
    • Fibroadenomatoid change associated with calcifications (see comment)
    • Comment: Correlation with specimen radiograph was performed.
Differential diagnosis
  • Fibroadenoma:
    • Well circumscribed mass comprised of stromal and epithelial components sharply demarcated from the surrounding breast parenchyma
Board review style question #1

A poorly circumscribed nodular focus was identified in a breast needle core biopsy, shown in the image. The best diagnosis for this histologic finding is which of the following?

  1. Apocrine metaplasia
  2. Duct ectasia
  3. Columnar cell change
  4. Fibroadenomatoid change
  5. Microcalcifications
Board review answer #1
D. Fibroadenomatoid change

Comment Here

Reference: Fibroadenomatoid change
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