Fibroadenoma: Clinical sciences

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Introduction0:00–0:41

A fibroadenoma is one of the most common benign tumors of the breast and occurs frequently in patients between the ages of 15 and 35 years.
Fibroadenomas arise from stromal and epithelial connective tissue cells, which contain receptors for both estrogen and progesterone, which makes these tumors sensitive to hormonal changes.
Although the exact etiology of fibroadenomas is unknown, reproductive hormones play a role in their development as they appear during the reproductive years, enlarge during pregnancy, and eventually regress after menopause.
Fibroadenomas can be classified as simple, complex, or giant.Alright, when a patient presents with signs and symptoms of a fibroadenoma, the first step is to obtain a focused history and physical examination.

History and Physical0:41–3:09

Patients typically present with a breast lump that’s usually painless. In addition, your patient may report changes in size throughout their menstrual cycle, as well as increase in size during pregnancy, or a decrease in size after menopause.
On physical examination, you can expect to find a solitary, palpable, unilateral breast mass. The lesion is usually solid, firm, and rubbery in nature with regular borders.
In addition, the mass is mobile and non-tender. Although the lesion can be located anywhere in the breast, it is most commonly found in the upper outer quadrant.
Based on your history and physical exam findings, you should suspect a fibroadenoma. Next, order some imaging to get a better idea of what’s going on.
If your patient is younger than 35 years, you can order a breast ultrasound; but, if your patient is 35 years of age or older, you should obtain both a breast ultrasound and a mammogram.
Here’s a clinical pearl! Breast findings on imaging can be categorized with a standardized system called BI-RADS, which stands for Breast Imaging-Reporting and Data System.
The imaging findings are assigned into categories labeled as 0 to 6. First, 0 means incomplete, which needs additional imaging or comparison with previous images if available.
Next, 1 is negative, meaning that mammography is normal, with no findings like masses or calcification; while 2 indicates findings are completely benign, meaning that mammography reveals findings with no probability of malignancy; a category of 0, 1, and 2 can only be used when undergoing routine screening.
On the other hand, 3 is probably benign, meaning that mammography may reveal a finding with minimal malignant potential of less than 2%, so these patients should get follow-up imaging.
Next, 4 is suspicious for malignancy, meaning that mammography may reveal a finding with malignant potential between 2 to 94%, where biopsy will likely be indicated.
Then, a category of 5 is highly suspicious of malignancy, with malignant potential over 95%. Lastly, 6 is known malignancy that has been proven with biopsy, and requires definitive management with surgery, chemotherapy, or radiation.
Alright, let’s go back to ultrasound and mammogram. Now, if imaging results are normal and there are no findings that would indicate a breast fibroadenoma, then you consider an alternative diagnosis.

Consider alternative diagnosis3:09–3:29

Of note, this would be considered BI-RADS category 1.However, in cases where a fibroadenoma is present, ultrasound and mammogram can be used to help classify fibroadenomas, and certain features may indicate if the fibroadenoma is simple, complex, or giant.

Simple fibroadenoma3:29–6:03

On the ultrasound, you could see an oval or round lesion, which is generally well-circumscribed and has uniform hypoechogenicity.
Similarly, a mammogram can show a well-circumscribed oval mass that is either hypodense or isodense to the surrounding breast glandular tissue.
The lesion can appear macrolobulated or with partially obscured margins. If you see these findings on imaging, you can suspect a simple fibroadenoma.
Asymptomatic patients can be considered BI-RADS category 3, so you can follow up with a repeat ultrasound in 6 months to assess stability.
If there are no changes on the follow-up ultrasound, your patient can return to routine annual screenings, which include clinical breast exams and serial ultrasounds every 6 months for the first year, and then again at the second year mark.
However, if your patient is symptomatic, reports pain and discomfort, or if the fibroadenoma is enlarging, an ultrasound-guided core needle biopsy can be done to see if it is some other type of malignant lesion.
If the biopsy reveals a well-circumscribed, non-encapsulated lesion with both stromal and glandular elements, your diagnosis of a simple fibroadenoma is confirmed.
Now, since fibroadenomas are benign and don’t increase the risk of developing breast cancer, most cases can be managed with observation and reassurance; while indications for surgical removal include atypia, unusual pathologic features, symptomatic cases, or cosmetic concerns.
There are three ways you can surgically manage simple fibroadenomas. The first option is the traditional open excisional biopsy, which is preferable for tumors larger than 4 cm, but it might not provide the best cosmetic result and may require longer healing time.
The next two options are ultrasound-guided cryoablation and ultrasound-guided vacuum-assisted percutaneous excision, which are both less invasive and provide better cosmetic results with faster recovery time.
However, keep in mind that they can’t be performed if the tumor is larger than 4 cm, or when you suspect malignancy based on clinical or pathological findings.
Okay, now that we have discussed simple fibroadenoma, let’s go back to imaging and talk about some different findings that might suggest a complex fibroadenoma.

Complex fibroadenoma6:03–8:05

On ultrasound, you will see similar features of a simple fibroadenoma but with additional findings such as internal calcifications, irregular borders, or lobulations.
Similarly, on a mammogram, you can expect to see a well-circumscribed oval or round mass with internal calcifications, better known as ‘popcorn’ calcifications, or other findings like obscured or irregular borders.
If you see a combination of these findings on imaging, you can suspect a complex fibroadenoma. In these cases, you can perform an ultrasound-guided core needle biopsy to confirm your suspicion.
If histopathology reveals sclerosing adenosis, duct epithelial hyperplasia, epithelial microcalcifications, and papillary apocrine changes, in addition to stromal and glandular elements of fibroadenomas, you can confirm the diagnosis of complex fibroadenoma.
Okay, when it comes to management, if the patient is asymptomatic, make sure to follow up in 6 months and repeat a clinical breast exam.
If there are no changes in the physical exam findings, your patient can continue with their routine annual screening and clinical breast exams.
On the other hand, symptomatic patients who experience pain and discomfort are managed with excisional biopsy, ultrasound-guided cryoablation, or vacuum-assisted percutaneous excision.
Here’s a high-yield fact! Some lesions will not have clear findings of complex fibroadenoma on biopsy.
Lesions with stromal mitoses or overgrowth, nuclear pleomorphism, or adipose tissue infiltration in the surrounding tissue carry an increased risk of developing breast cancer.
As a general rule, any lesion with an increased risk of cancer needs to be fully excised regardless of symptomatology. Now that complex fibroadenomas are taken care of, let’s go back to imaging once more.

Giant fibroadenoma8:05–9:38

On ultrasound you might see a large oval or round lesion that’s larger than 5 cm in size. The mass will likely be well-circumscribed with uniform hypoechogenicity.
On a mammogram, you’ll see a large, well-circumscribed mass that can be either hypodense or isodense in relation to the surrounding breast glandular tissue.
Additionally, the lesion can be macrolobulated or with partially obscured margins. If you see these huge masses, suspect a giant fibroadenoma, and if concerned your next step is to perform an ultrasound-guided core needle biopsy to confirm your diagnosis.
Speaking of diagnosis, here’s a high-yield fact! Giant fibroadenomas can often be confused with phyllodes tumors, which show a leaf-like growth pattern, so accurate tissue diagnosis is very important, especially when they increase in size rapidly.
Okay, so the histopathology of giant fibroadenomas will typically show hypercellular stroma, with epithelial and myoepithelial hyperplasia in addition to the proliferation of stromal and epithelial cells without a leaf-like growth pattern.
If you see these cellular characteristics, you can confirm your diagnosis of giant fibroadenoma. Because of the size of these lesions, these lesions should undergo surgical excision as the treatment option, while less invasive excision techniques wouldn’t be appropriate.Alright, as a quick recap… Fibroadenomas are common benign breast tumors frequently found in patients between 15 and 35 years old.

Review9:38–10:53

The diagnostic workup requires ultrasound, while patients older than 35 years need a mammogram too. Asymptomatic simple fibroadenomas should be followed up with a repeat ultrasound in 6 months.
Symptomatic simple fibroadenomas need histopathologic confirmation with ultrasound-guided core needle biopsy before removing them with excisional biopsy, ultrasound-guided cryoablation, or ultrasound-guided vacuum-assisted percutaneous excision.
Complex and giant fibroadenomas typically require a core needle biopsy to confirm the diagnosis. Asymptomatic complex fibroadenoma can be followed up with a clinical breast exam in 6 months; if there are no changes, the patient can continue with routine annual screenings.
Symptomatic complex fibroadenomas can be surgically removed with excisional biopsy, ultrasound-guided cryoablation, or ultrasound-guided vacuum-assisted percutaneous excision.
Lastly, giant fibroadenomas should undergo surgical excision.