This article gives an overview of one of the most common benign breast lesions ; including a relevant anatomy, epidemiology and pathophysiology (including it's risk factors, classification, aetiology, gross and microscopic pathology It also includes the clinical features, and imaging and histologic evaluation of such masses

1. DESCRIBE THE SURGICAL PATHOLOGY AND PATHOPHYSIOLOGY OF FIBROADENOMA OF THE
BREAST
BY
DR OFURE OMOIKE AKHATOR

2. OUTLINE
• INTRODUCTION
• RELEVANT ANATOMY
• PATHOLOGY
• CLASSIFICATION
• EPIDEMIOLOGY
• ETIOLOGY
• RISK FACTORS
• PATHOPHYSIOLOGY
• MACROSCOPIC AND MICROSCOPIC FEATURES
• CLINICAL FEATURES
• INVESTIGATION
• TREATMENT
• DIFFERENTIAL DIAGNOSIS
• PROGNOSIS
• CURRENT TRENDS
• CONCLUSION
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3. INTRODUCTION
• Most frequently encountered benign breast lesion in young women
• A fibroepithelial lesion, characterized by an admixture of stromal and
epithelial tissue,
• It’s exact etiology is uncertain, a hormonal cause is doubtless- a focal
aberration of normal development of a single lobule
• Usually a well defined, firm and solitary mass
• Surrounded by a well defined capsule
• A proper understanding of its pathophysiology and pathology is
essential in proper management of the patient
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4. RELEVANT ANATOMY
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5. RELEVANT ANATOMY
• The acinus, groups of which form the lobule surrounded by fat and drained
by branching lobular ducts into lactiferous ducts.
• Groups of lobules coalesce to form 15-20 larger lobes which drain into the
lactiferous (or major) ducts that open separately on the nipple.
• The acini are lined by cuboidal epithelium
• Interspersed within the basal row of cells are the myoepilhelial
cells which are believed to effect the ejection of milk.
• The bulk of the areola and nipple is made up of contractile smooth muscle
fibres
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6. PATHOLOGY
CLASSIFICATION
• SIMPLE FIBROADENOMA
Usually gain a size of 2-3cm
More lobular component
• COMPLEX FIBROADENOMA
Occurs in older age group
Associated with a slightly increased risk of cancer
May include changes as cysts with microcalcifications, stromal fibrosis,
apocrine metaplasia- fibrocystic changes
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7. PATHOLOGY
CLASSIFICATION
• GIANT FIBROADENOMA
Fibroadenoma greater than 5cm in size, or 500g
Also characterized by its rapid growth
May cause asymmetry of breast, distortion of overlying skin
Usually encountered in pregnant/ lactating mothers
Commonly seen in females of Afro-Caribbean or East Asian descent
More cellular with less lobular component
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8. PATHOLOGY
EPIDEMIOLOGY
• Most common benign breast lesion
AGE
• Rare before menarche
• Most common in adolescent girls and women < 35years except for
complex fibroadenoma
RACE
• More common in young African-Americans
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9. PATHOLOGY
RISK FACTORS
• Age <35years
• Higher socioeconomic class
• Family history of breast cancer in first degree relatives
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10. PATHOLOGY
ETIOLOGY
• Sporadic
• Cyclosporine immunosuppression
• Carney complex
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11. PATHOPHYSIOLOGY
• An aberration of a developing
terminal duct lobular unit
• Hormonal relationship likely
• Increases in size with
pregnancy, estrogen use
• Develops during the
reproductive period
• It may double in size in 6-12
months during growth
• May regress after menopause
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12. PATHOPHYSIOLOGY
NATURAL HISTORY
• Some remain stable
• Others demonstrate growth
• May regress (as they lose cellularity)
• Calcifications can form within the hyalinized or necrotic stroma of
involuting fibroadenomas (coarse popcorn-like calcifications)
• Rarely, malignant transformation (<0.3%)
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13. PATHOLOGY
MACROSCOPIC
Usually measures 1-5cm
but can be of very large
size also
Well circumscribed,
grayish white firm
rubbery nodule
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14. PATHOLOGY
MACROSCOPIC
Cut section- Fleshy, uniformly
grey white with small slit like
spaces and gelatinous
appearance
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15. PATHOLOGY
MICROSCOPIC
Tumor consists of proliferating epithelial and mesenchymal
components
Stroma proliferates around tubular ducts (pericanalicular) or
compressed cleft like ducts (intracanalicular)
Ducts are lined by luminal epithelial cells and outer myoepithelial
cells
Luminal epithelial cells may show hyperplasia; atrophic change,
apocrine change or squamous metaplasia may also occur
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16. PATHOLOGY
MICROSCOPIC
• Stroma is typically low in cellularity and does not show significant nuclear
atypia
• Stroma shows abundant hyalinization and myxoid change
• Stromal alterations which can occur include
• Calcifications
• Adipose tissue
• Chondroid or osseous metaplasia
• Smooth muscle metaplasia
• Bizarre multinucleated giant cells
• Infarction may develop during pregnancy or lactation
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17. PATHOLOGY
MICROSCOPIC
• Intracaualicular fibroadenoma:
It usually occurs between 30 and 50 and occasionally around
puberty; it grows less slowly than the pericanalicular type.
When cut across, it looks like cysts enclosing cauliflower-like
masses. Microscopically, the delicate connective tissue shows
extensive proliferation which projects into the ducts thereby
elongating, dilating and distorting !hem. Rarely, there may be
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18. Intracaualicular fibroadenoma:
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19. PATHOLOGY
MICROSCOPIC
• Pericanalicular fibroadenoma:
It is much commoner than the intracanalicular type
occurs in the age group 14-30
witha peak incidenceat21·25.
It is usually round or oval
 l-3cm in diameter.
It is well encapsulated by a sheath of fibrous tissue to which iris attached by a
pedicle.
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20. PATHOLOGY
MICROSCOPIC
• Pericanalicular fibroadenoma:
Microscopically, it consists of an overgrowth of fibrous, acinar and ductal epithelial
structures resembling normal breast tissue.
The fibrous tissue is most dense around the ducts; hence the term pericanalicular.
Clinically the tumour is firm, not attached to any tissue
very mobile within the breast
The surface is smooth or finely granular.
Occasionally it may be multiple.
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21. Pericanalicular fibroadenoma
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22. CLINICAL FEATURES
• Occur between ages 15-25years, occasionally in much older women
• Painless lump
• Usually solitary, can be multiple or bilateral
• Located anywhere in the breast but majority situated in the upper
outer quadrant
• Classically well defined, mobile (breast mouse), smooth, firm, non
tender
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23. INVESTIGATION
IMAGING ASSESSMENT
• The patient’s age dictates the
recommended first imaging
modality
• Appear as hypoechoic mass
with a circumscribed border on
Ultrasound
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24. INVESTIGATION
IMAGING ASSESSMENT
• Demonstrated as an oval/
round mass with a
circumscribed margin on
Mammogram, calcifications
are occasionally seen
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25. INVESTIGATION
HISTOLOGY
• Core needle biopsy preferred to FNAC
• Patients <40years with with Breast Imaging-Reporting And Data
System (BIRADS) 3 can be safely followed with careful surveillance
• If >40years with masses with benign features on imaging, biopsy
should be considered
• Women with BIRADS 4 should be biopsied
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26. TREATMENT
• SURVEILLANCE
Observation alone for masses less than 2cm
Short term imaging follow up for masses with benign features
• SURGICAL EXCISION
Indicated if there is associated atypia, unusual pathologic features or
cosmetic concerns
Ultrasound guided cryoablation
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27. DIFFERENTIAL DIAGNOSIS
• PHYLLODES TUMOR
• Characterized by abundant cellular stroma, stroma nuclear pleomorphism,
and leaf like processes projecting into cystic spaces
• HAMARTOMA (Fibroadenolipoma)
• Usually soft
• Integral adipose tissue
• BREAST Ca
• LIPOMA
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28. PROGNOSIS
• Good
• Constitute minor risk (1.6-2.17) for the development of breast cancer
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29. CURRENT TRENDS
• High Intensity Focused Ultrasound (HIFU)
• Ultrasound guided vacuum-assisted percutaneous excision
• Radiofrequency Ablation
• Laser Ablation
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30. CONCLUSION
• Fibroadenomas are common benign solid tumours containing
glandular and fibrous tissue
• They are most commonly found in women between 15 and 20years
• Etiology is not known but a hormonal relationship is likely
• They are aberrations of normal development of a terminal duct
lobular unit
• Usually solitary, firm, well circumscribed masses with glandular and
stromal components
• May be managed conservatively or excised
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31. THANK YOU
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32. REFERENCES
• Bailey, H. et al (2016) Bailey and Love’s short practice of surgery (26th ed.)
CRC Press
• ARCHAMPONG, E.Q et al (2015) Baja’s principles and practice of surgery:
including pathology in the tropics (5th edition)
• Jingmei Li et al (2018) Family history, reproductive and lifestyle risk factors
for fibroadenoma and breast cancer. JNCI cancer spectr. doi:
10.1093|jncics|pky051
• WHO classification of breast tumours, 5th edition, vol2
• Kopkash K, Yao K (2020) The surgeon’s guide to fibroadenomas. Annals of
breast surgery, doi:10/21037/abs-20-100
• Shanthi, V (2012) Fibroadenoma. Histopathology guru
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