Primarius Milos Pocekovac MD,PhD
Sava Stajic MD, MSc
What is a fibroadenoma?
Fibroadenomas are benign tumors made out of stromal lobuli of the breast. Fibro – connective tissue, adenoma – glandular tissue.
World health organization defined fibroadenomas as a “discrete
benign tumor” which shows the presence of connective tissue
and epithelial proliferation. Fibroadenomas are the most
common benign alteration of the breast which is present in 25%
of asymptomatic women. This is a common change of the breast
of a young woman in reproductive age. It appears to be due to
the disbalance of hormones. Fibroadenomas are benign tumors
made out of stromal tissue of the lobuli of the breast. This is the
reason why they are most commonly active from the age of 15
to 25, when lobular development is most active.
Usually they are singular. Sometimes multiple. Most commonly
they are located in the left breast. They are more common in
women of African descent.
Diagnosis is made by ultrasound, if the patient is under the
age of 30 or mammography in older women.
What is the cause of the fibroadenoma?
Etiology of fibroadenomas is not known, but the fact that
lobular proliferation response to estrogen stimulation which
suggests that the fibroadenomas are a result of estrogen
When does it appear?
Most commonly between 15 and 25 years of age when the
reproductive life is most active.
Can lifestyle increase or lower the risk of fibroadenomas?
Widespread use of contraceptive pills in young women makes
it more difficult to get precise data of their role in
pathogenesis. There is no significant evidence that
contraceptive pills increase the risk of development of
fibroadenomas, but the epidemiological data suggests that
they can be connected to the lowered incidence of
development. The majority of research shows that risk of
development is cut in half in the women that take
contraceptives, especially in the long term users.
Epidemiological studies suggest that progesterone has the
protective role. Cani published a research that show that
women under the age of 45 have a decreased risk and women
over that age have increased risk of development. Smoking
also appears to have a protective role in the regarding the
occurrence. Roan and Miller from Canada showed that there is
a decreased rick in the active smoker. Fibroadenomas are
more common in women of higher socio economic strata. If
was found that high amounts of Vitamin C can be linked to the
lower risk of development as are BMI and multiple
pregnancies. Previous benign lesions and women under the age
of 35 have increased rick. Epstein Barr virus can have a
causative role in the tumor development in immunosuppressed
Can fibroadenoma grow or decrease in size during a life time?
Numerous studies were performed where fibroadenomas were
treated conservatively. The first large study, done by Dent and
Kant followed 63 young women in Cape town, with clinical and
cytological diagnosis of fibroadenoma. They proved that
lesion in 31% of cases disappeared in 12% of cases got smaller
in size in the period of follow up from 13-24 months, 25%
remained unchanged and 32% have grown in the same period.
The Edinburg study 4 201 women were followed, under 40
years of age, and they were offered the conservative
treatment after the confirmed diagnosis of fibroadenoma by
clinical finding, ultrasound and cytology. Histological
confirmation was made in all of 17 cases of women that opted
for surgery, which confirms the triad of diagnostics. Two
thirds of tumors were smaller than 2cm in diameter, one third
was in the range of 2-4 cm. Objective evaluation of size of the
tumor was made by ultrasound. During the follow up period in
13% of cases the fibroadenoma was gone or became smaller in
size, 85% remained unchanged and in 2% of cases they have
grown in size. In 4 cases they were surgically removed and
there was a histological confirmation of simple fibroadenoma.
So it was concluded that most fibroadenomas remain static in
growth in the several years after the diagnosis and in some
cases it can even get smaller in size and in a very small
number of cases they can grow in size.
Takei et al made an equation that anticipated the rate by
which fibroadenomas in Japanese women changed in size from
the age of 20 to 40 years old (0,34mm decrease in size per
What kinds of fibroadenomas exist?
Simple, Complex, Multiple, Gigantic, Juvenile (in
Are all fibroadenomas “harmless”?
Complex fibroadenomas can increase the risk of carcinoma of
Can fibroadenomas develop into breast cancer?
Cancer is a rare complication in fibroadenomas.
The Hasagen study showed only 2 cases in the period of 45
years which became lobular carcinoma.
Another study done by Diaz et al. reported 105 cases of
carcinoma developed from fibroadenomas. The average age of
the patient was 44, and clinical characteristics did not
differentiate from other patient with simple fibroadenomas. In
95% of these cases the carcinoma in situ was inside the
fibroadenoma. Lobular and ductal type of tumor distribution
was equal. Axillar nodal metastasis was not found. Authors
suggested the sparing surgery from the carcinoma in situ
which came from the fibroadenoma.
Some studies have shown that the incidence of carcinoma
inside the fibroadenoma is from 0,002% to 0,0125%. Around
50% of these tumors are noninvasive lobular carcinomas and
20% are invasive lobular carcinomas, 20% are invasive ductal carcinoma, 20% are ductal noninvasive carcinomas and the remaining 10% are invasive ductal carcinomas.
Clinically, upon ultrasound and mammographic findings were
similar as in benign fibroadenomas.
How can you treat the fibroadenomas?
Fibroadenomas can cause a physical deformity due to the size,
inconvenience or emotional stress. Patient needs to be
informed about the possibilities of treatment whether it is
surgical or conservative methods as well as the percentage of
Cryoablation was recently described as a method to root out
the fibroadenomas, after a biopsy established diagnosis by
core biopsy. Freeze technology is used (via cold liquid
nitrogen). This is minimally invasive procedure. A probe is
inserted into the fibroadenoma guided by ultra sound. Aragon
gas is circulated through the probe and at its point and
temperature falls to -196 degrees making a “frozen ball” that
encapsulates the fibroadenoma. After defrosting, the probe is
removed, and the fibroadenoma in time becomes smaller or
disappears. The advantages are smaller incision (3mm on the
skin), quick recovery, smaller risk of infection comparing to
standard procedures, no stiches and no changes in the shape
of the breast. It is necessary to confirm the diagnosis
beforehand by a core biopsy.
Though simple, it is impossible to be certain that
fibroadenoma is completely removed and hematoma occurring
after surgery is inevitable.
Indications for surgical treatment are:
- – Enlargement of the lesions during regular ultra sound
- – Fibroadenoma >2cm
- – Unsure diagnosis
- – Anxiety of the patient
Classical surgical treatment entails total excision of the
fibroadenoma through a small incision. Some surgeons suggest
that if the fibroadenoma is close to the skins surface to
perform the surgery in local anesthesia, and for the deeper
changes to do the surgery in general anesthesia which is more
appropriate for the patient and the surgeon. Hospitalization in
all cases is a few hours.
Type of surgical excision should depend on the clinical and
radiological presentation. Excision should spare most of the
healthy glandular tissue. Scar should be as small as possible
and almost invisible, done in the manner of plastic surgery, in
its positioned and in the type of suture chosen.
Sub mammary approach is suggested, but if the lesion is too
far away from this location this approach can extend the time
spent in surgery. Beforehand the lesion should be marked on
the skin in the lying down position with a clinical and ultra
sound exam. This way there the risk of missing the lesion is
Most common types of incisions are:
- Around the areola
- Sub/ Infra mammary
First pointer is showing the possibility of the periareolar
incision depending on the location of the change, and the
other is showing the infra mammary approach.
Infra mammary incision leaves a barely visible scar.
Periareolar incision also leaves a barely visible scar and allows
aces to any quadrant of the breast tissue. In this way multiple
fibroadenomas can be removed as well.