- Fibroadenomas:
- Are benign tumors composed of stromal and epithelial elements
- That are commonly seen in young women
- Multiple or complex fibroadenomas:
- May indicate a slightly increased risk for breast cancer:
- The relative risk of breast cancer in patients with such fibroadenomas:
- Is approximately twice that of patients of similar age without fibroadenomas
- The relative risk of breast cancer in patients with such fibroadenomas:
- May indicate a slightly increased risk for breast cancer:
- A patient’s age determines the preferred imaging method:
- In general, ultrasonography (US) is preferred:
- If a palpable mass is found
- If a patient is younger than 30 years
- If the patient is pregnant
- Mammography and US are both useful if the patient has:
- A palpable mass
- Is older than 30 years
- Is not pregnant o In patients younger than 30 years:
- The most appropriate modality is US:
- Because the patient is spared radiation exposure and because the likelihood for fibroadenoma is not that high
- The most appropriate modality is US:
- Mammography is not indicated as the primary imaging study in women younger than 30 years:
- Unless high-risk factors are present
- Computed tomography (CT) scanning:
- Is not initially indicated for assessing a palpable lump in a woman in women younger than 30 years:
- Because of radiation exposure
- The inability of CT to demonstrate micro-calcifications
- The lack of specificity in the findings
- Is not initially indicated for assessing a palpable lump in a woman in women younger than 30 years:
- Magnetic resonance imaging (MRI):
- Is not initially indicated for assessing a palpable lump in women younger than 30 year:
- Mainly because of its high cost and the high likelihood of false-positive finding
- Is not initially indicated for assessing a palpable lump in women younger than 30 year:
- Positron emission tomography:
- Is expensive and is not universally available
- In general, ultrasonography (US) is preferred:
- On mammograms:
- Fibroadenomas typically appear as:
- Circumscribed oval or round masses:
- Which occasionally have coarse calcifications
- Circumscribed oval or round masses:
- Fibroadenomas typically appear as:
- On ultrasonograms:
- Fibroadenomas appear as circumscribed, homogeneous, oval, hypoechoic masses:
- That may have gentle lobulations
- A smooth, thin, echogenic capsule
- Variable acoustic enhancement; and homogeneity
- Fibroadenomas appear as circumscribed, homogeneous, oval, hypoechoic masses:
- On MRI:
- Fibroadenomas typically appear as smooth masses with high signal intensity on T2-weighted images and enhancement with the administration of gadolinium-based contrast agent
- Fibroadenoma:
- Is a common benign breast lesion:
- Results from the excess proliferation of connective tissue
- Fibroadenomas characteristically contain both:
- Stromal and epithelial cells
- Is a common benign breast lesion:
- Epidemiology:
- They usually occur in women:
- Between the ages of 10 and 40 years
- It is the most common breast mass:
- In the adolescent and young adult population
- Their peak incidence is between:
- 25 and 40 years
- The incidence decreases after 40 years
- Fibroadenomas commonly enlarge during pregnancy and involute at menopause: • Hence, they rarely present after the age of 40 years o The lesions are well defined and well-circumscribed clinically and the overlying skin is normal o The lesions are not fixed to the surrounding parenchyma and slip around under the palpating fingers: Hence the colloquial term a breast “mouse”. • Pathology: o A fibroadenoma is a type of adenomatous breast lesion: It contains epithelium Has minimal malignant potential o Multiple fibroadenomas occur in: 10% to 15% of patients: • Patients with multiple fibroadenomas: o Tend to have a strong family history of these tumors o They are assumed to be: Aberrations of normal breast development (ANDI) or the product of hyperplastic processes: • Rather than true neoplasms o Fibroadenomas can be stimulated by estrogen and progesterone o Some fibroadenomas also have receptors and respond to: Growth hormone and epidermal growth factor o When found in an adolescent girl: The term juvenile fibroadenoma is more appropriate • Location: o Although they can be located anywhere in the breast: There may be a predilection for the upper outer quadrant • Associations: o Cyclosporin use o Cowden syndrome • Radiographic features: o Mammography: Fibroadenomas have a spectrum of features: • Well-circumscribed discrete oval mass hypodense or isodense to the breast glandular tissue • Mass with macro-lobulation or partially obscured margin • Involuting fibroadenomas in older, typically postmenopausal patients may contain: o Calcification: Often producing the classic, coarse popcorn calcification appearance In some cases the whole lesion is calcified Calcification may also present as crushed stone-like micro-calcification which makes differentiation from malignancy difficult • Breast ultrasound: o Typically seen as a well-circumscribed, round to ovoid, or macro-lobulated mass with generally uniform hypoechogenicity o Intralesional sonographically detectable calcification: May be seen in approximately 10% of cases o Sometimes a thin echogenic rim (pseudo capsule) may be seen sonographically • Breast MRI: o T1: typically hypo intense or isointense compared with adjacent breast tissue o T2: can be hypo- or hyper intense o T1 C+ (Gd): can be variable but a majority will show slow initial contrast enhancement followed by a persistent delayed phase (type I enhancement curve); non-enhancing internal septations may be seen • Diagnosis: o These lesions are easily biopsied under ultrasound guidance o When a lesion has the typical features of a fibroadenoma on ultrasound and there are no clinical red flags: They can be safely followed clinically o When lesions enlarge or have atypical imaging findings: Ultrasound-guided core biopsy is a minimally invasive outpatient procedure that will give a diagnosis with virtually no complications o There may be a maximum diameter above which a biopsy should be done if no previous imaging is available: The reason for intervention based on size is that a phyllodes tumor may be indistinguishable from a fibroadenoma on ultrasound: • A maximum diameter of 2.5 cm may be a useful benchmark for biopsy if you have no previous imaging o Interval enlargement is an indication for biopsy • Treatment and prognosis: o They are benign lesions with minimal or no malignant potential o The risk of malignant transformation is extremely low: Has been reported to range around 0.0125% to 0.3%. o Indications for biopsy include: Enlarging lesion Atypical findings on ultrasound A lesion above 2.5 cm and there are no previous studies for comparison Patient peace of mind: • Some patients are simply not happy with a palpable mass in the breast without a histological diagnosis: o This is a valid and reasonable indication for biopsy
- They usually occur in women:
Fibroadenoma
Rodrigo Arrangoiz MS, MD, FACS, FSSO 