Breast
Fibrocystic changes
Radial scar / complex sclerosing lesion

Editorial Board Member: Gary Tozbikian, M.D.
Editor-in-Chief: Debra Zynger, M.D.
Kristen E. Muller, D.O.

Topic Completed: 18 August 2020

Minor changes: 18 August 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Radial scar [title] breast

Kristen E. Muller, D.O.
Page views in 2019: 8,874
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Cite this page: Muller KE. Radial scar / complex sclerosing lesion. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastradialscar.html. Accessed September 29th, 2020.
Definition / general
  • Benign breast lesion comprised of a central fibroelastotic stromal core with radiating ducts and lobules with varying degrees of proliferative and cystic changes arranged in a stellate configuration
Essential features
  • Benign breast lesion comprised of a central fibroelastotic stromal core with radiating ducts and lobules with varying degrees of proliferative and cystic changes arranged in a stellate configuration
  • May simulate invasive carcinoma mammographically, clinically, grossly and microscopically
  • Atypia or malignancy may arise within or in association with radial scars / complex sclerosing lesions
  • Treatment ranges from observation with clinical and radiologic follow up to surgical excision
Terminology
  • Radial sclerosing lesion, complex sclerosing lesion (> 1.0 cm)
ICD coding
  • ICD-10: N64.89 - Other specified disorders of breast
  • ICD-11: GB20.Y - Other specified benign breast disease
Epidemiology
Sites
  • Breast parenchyma
Pathophysiology
  • Pathogenesis uncertain
  • Stromal-epithelial interactions and increased expression for several factors involved in formation of vascular stroma may play a role (Hum Pathol 2002;33:29)
Etiology
  • Unknown
  • Scar is a misnomer; not related to prior trauma or surgery
Clinical features
  • Most often incidental microscopic findings in breast tissue removed for other targets / abnormalities; however, some palpable (Clin Radiol 1993;48:319)
Diagnosis
  • Imaging: ultrasound, mammogram, MRI
  • Invasive procedure: core needle biopsy, fine needle aspiration (not recommended)
Radiology description
Radiology images

Contributed by Kristen E. Muller, D.O.

Mammogram, spiculated mass

Ultrasound, hypoechoic mass

Prognostic factors
Case reports
Treatment
Gross description
  • Stellate, rubbery to firm mass with retracted center; resembles invasive ductal carcinoma
  • Usually 1 cm or less; complex sclerosing lesions > 1 cm
  • May be firm, irregular, with yellow streaks and flecks (due to elastotic stroma)
Gross images

AFIP images

Central sclerosis and elastosis resembling carcinoma

Microscopic (histologic) description
  • Low power stellate configuration
  • Central sclerotic zone composed of fibrosis and elastosis with ducts and lobules radiating outward between bands of sclerotic tissue
  • Central core frequently contains small entrapped obliterated ductules that may mimic invasive carcinoma; squamous metaplasia may occur in central nidus
  • Variable amounts of usual ductal hyperplasia (may be florid with necrosis), sclerosing adenosis, apocrine metaplasia and cysts
  • Stroma tends to be more cellular in early lesions and more collagenized and sclerotic with abundant elastin in older lesions
  • Atypical hyperplasia (ADH, ALH) observed in 21 - 51% (Breast Cancer Res Treat 2008;107:371, Cancer 2003;97:345)
  • In situ or invasive carcinoma may arise within or in association with radial scar / complex sclerosing lesions
  • Complex sclerosing lesions are larger (typically > 1 cm) and show features of radial scar that combine and converge with intermingling areas of sclerosis, entrapped and distorted glands and fibrocystic changes; however, may not have the well defined configuration of radial scar
Microscopic (histologic) images

Contributed by Kristen E. Muller, D.O.

Stellate architecture

Central fibroelastotic core


Central fibroelastotic core

Squamous metaplasia

Usual ductal hyperplasia and cysts

Complex sclerosing lesion


With atypical ductal hyperplasia

With atypical lobular hyperplasia

With invasive ductal carcinoma

Tubular carcinoma for comparison



Contributed by Emily S. Reisenbichler, M.D.

Central sclerosis with fibroelastotic stroma and entrapped glands radiating outward

Virtual slides

Images hosted on other servers:

Complex sclerosing lesion

Cytology description
  • FNA not reliable for diagnosis; may show usual ductal hyperplasia, apocrine metaplasia and spindle shaped stromal cells (Diagn Cytopathol 1997;16:537)
Positive stains
Molecular / cytogenetics description
  • Focally increased numbers of blood vessels and expression of mRNA for collagen type 1, total fibronectin, ED-A+ fibronectin, thrombospondin 1, VPF / VEGF and KDR (Hum Pathol 2002;33:29)
  • Allelic imbalance chromosome 16q and 8p; some areas may be clonal (Hum Pathol 2002;33:715)
Sample pathology report
  • Right breast, needle core biopsy:
    • Radial scar (see comment)
    • Microcalcifications: associated with radial scar
    • Comment: The radial scar measures 4 mm and appears adequately sampled and completely excised in this biopsy. No atypia or malignancy is identified. Clinical and radiologic correlation is recommended.
  • Right breast, needle core biopsy:
    • Complex sclerosing lesion (see comment)
    • Microcalcifications: not identified
    • Comment: The biopsy shows several tissue cores containing a complex sclerosing lesion comprised of benign glands with varying degrees of fibrocystic changes (usual ductal hyperplasia, cysts and apocrine metaplasia) radiating around a central fibroelastotic core. No atypia or malignancy is identified. The largest contiguous microscopic measurement in a single tissue core is 7 mm. Clinical and radiologic correlation is recommended to ensure adequate sampling of the targeted lesion.
Differential diagnosis
  • Invasive ductal carcinoma:
    • Lacks myoepithelial cells
    • Infiltration into surrounding fat / breast parenchyma may be a clue
    • Tumor cells show cytologic atypia
  • Tubular carcinoma:
    • Glands show distinctive angulated shapes
    • Lacks myoepithelial cells
    • Infiltration into surrounding fat / breast parenchyma may be a clue
    • Surrounding usual ductal hyperplasia, apocrine metaplasia and cysts commonly seen at the periphery of radial scars typically absent
  • Low grade adenosquamous carcinoma:
    • Irregular glands with varying degrees of squamous differentiation
    • Infiltrative pattern; if arising within a radial scar / complex sclerosing lesion, the malignant cells infiltrate beyond the sclerosing lesion
    • Lymphoid aggregates within and at periphery of the lesion may be a clue
    • Variable expression of myoepithelial and cytokeratin markers
    • Negative for ER, PR, HER2
Board review style question #1

Which of the following is true regarding the lesion pictured?

  1. It is frequently associated with concurrent invasive cancer
  2. All the glands lack myoepithelial cells and invade into adipose tissue
  3. Imaging features include irregular spiculated mass with dense center frequently mimicking invasive carcinoma
  4. There is a known association with malignant phyllodes tumors
Board review answer #1
C. This is a radial scar. Imaging features include irregular spiculated mass with dense center frequently mimicking invasive carcinoma

Comment Here

Reference: Radial scar
Board review style question #2
Which statement is true regarding the treatment and prognosis of radial scars and complex sclerosing lesions?

  1. They require excision since malignancy is found in 50 - 65% of excision specimens
  2. Management options include surgical excision and observation without surgery
  3. They confer a fourfold increased risk for developing breast cancer
  4. Small (< 5 mm) radial scars are more likely to be upgraded on excision
Board review answer #2
B. Management options include surgical excision and observation without surgery

Comment Here

Reference: Radial scar
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