Breast
Fibrocystic changes
Radial scar / complex sclerosing lesion
Author: Kristen E. Muller, D.O.
Editorial Board Member: Gary Tozbikian, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 18 August 2020
Last staff update: 30 December 2021
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Radial scar [title] breast
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Virtual slides | Cytology description | Positive stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Muller KE. Radial scar / complex sclerosing lesion. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/breastradialscar.html. Accessed April 19th, 2024.
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
Epidemiology
- 40 - 70 years
- Common; incidence 0.03 - 0.09% in screening populations (J Clin Pathol 2003;56:721)
- Similar frequency in benign (28%) and cancer (26%) specimens (Histopathology 1985;9:287, Hum Pathol 1984;15:475)
- Frequently multicentric and bilateral (J Pathol 1985;147:23, Ann Diagn Pathol 2015;19:24, Semin Diagn Pathol 2010;27:5, Histopathology 1985;9:287)
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
- Spiculated mass, architectural distortion, may be indistinguishable from invasive carcinoma (J Med Imaging Radiat Oncol 2010;54:415, Ochsner J 2015;15:219)
- Radiolucent or dense center
- Microcalcifications may be present
- Irregular hypoechoic mass with ill defined borders and posterior acoustic shadowing on ultrasound (Ultrasonography 2014;33:58)
- MRI enhancement characteristics variable (Breast J 2005;11:23, Breast J 2019;25:393, Can Assoc Radiol J 2020 Jun 10 [Epub ahead of print])
Radiology images
Contributed by Kristen E. Muller, D.O.
Mammogram, spiculated mass
Ultrasound, hypoechoic mass
Prognostic factors
- Associated risk with invasive breast cancer debated:
- Not found to be independently associated with increased risk of breast cancer (Cancer 2006;106:1453, Breast Cancer Res Treat 2008;108:167, Cancer Causes Control 2010;21:821, Eur J Surg Oncol 2011;37:709)
- Independently associated with a twofold increased risk of breast cancer, which may increase with larger and multiple radial scars (N Engl J Med 1999;340:430)
- Rare association with adenosquamous carcinoma (Histopathology 2000;36:203, Mod Pathol 2003;16:893)
- Size greater than or less than 10 mm does not influence prognosis (comparing radial scar and complex sclerosing lesion) (Eur J Surg Oncol 2011;37:709)
Case reports
- 32 year old woman with radial sclerosing lesion mimicking invasive carcinoma (Case Rep Oncol 2012;5:99)
- 40 year old woman with secretory carcinoma arising in a radial scar (Indian J Pathol Microbiol 2009;52:83)
- 45 year old with bilateral, multicentric adenosquamous carcinomas arising within radial scars / complex sclerosing lesions (Pathology 2014;46:85)
- 57 year old woman with DCIS arising in a radial scar (Breast Cancer 2006;13:107)
Treatment
- Ranges from excision to clinical observation due to variation in reported upgrade rates to malignancy at excision
- Upgrade rates for radial scar without atypia: 0 - 16%; mean: 7% (Mod Pathol 2016;29:1471)
- May not warrant routine surgical excision given low upgrade rates if multidisciplinary approach taken including radiologic-pathologic correlation, clinical and imaging follow up (Breast Cancer Res Treat 2018;170:313, Breast J 2018;24:133, Breast 2016;30:201, Am J Surg Pathol 2015;39:779, Surg Pathol Clin 2018;11:1, Springerplus 2016;5:398)
- Incidental and small (< 5 mm) radial scars less likely to be upgraded on excision (Arch Pathol Lab Med 2015;139:1137)
- If atypia is present, manage according to standards for the concurrent high risk lesion (J Clin Pathol 2019;72:800)
- Vacuum assisted large core biopsy may be reliable for excluding malignancy without surgery (Histopathology 2019;75:900, Breast Cancer Res Treat 2019;174:165)
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
- Myoepithelial stains: p63, calponin, CD10, smooth muscle myosin heavy chain, smooth muscle actin, CK5
- Central part of the lesion may show attenuated or absent myoepithelium
- Suggested panel: smooth muscle myosin heavy chain, calponin and p63 (Am J Surg Pathol 2010;34:896)
- Elastic 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
Additional references
Board review style question #1
Which of the following is true regarding the lesion pictured?
- It is frequently associated with concurrent invasive cancer
- All the glands lack myoepithelial cells and invade into adipose tissue
- Imaging features include irregular spiculated mass with dense center frequently mimicking invasive carcinoma
- There is a known association with malignant phyllodes tumors
Board review style 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
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?
- They require excision since malignancy is found in 50 - 65% of excision specimens
- Management options include surgical excision and observation without surgery
- They confer a fourfold increased risk for developing breast cancer
- Small (< 5 mm) radial scars are more likely to be upgraded on excision
Board review style answer #2
B. Management options include surgical excision and observation without surgery
Comment Here
Reference: Radial scar
Comment Here
Reference: Radial scar
