Cystosarcoma Phyllodes
Introduction
Background
Cystosarcoma phyllodes is a rare, predominantly benign
tumor that occurs almost exclusively in the female breast. 1 Its
name is derived from the Greek words sarcoma, meaning
fleshy tumor, and phyllo,meaning leaf. Grossly, the tumor
displays characteristics of a large, malignant sarcoma, takes
on a leaflike appearance when sectioned, and displays
epithelial, cystlike spaces when viewed histologically (hence
the name). Because most tumors are benign, the name may
be misleading. Thus, the favored terminology is now
phyllodes tumor.
Pathophysiology
Phyllodes tumor is the most commonly occurring
nonepithelial neoplasm of the breast, although it represents
only about 1% of tumors in the breast.2 It has a smooth,
sharply demarcated texture and typically is freely movable. It
is a relatively large tumor, with an average size of 5 cm.
However, lesions of more than 30 cm have been reported.
Frequency
United States
No difference in phyllodes tumor frequency appears to exist
between patients from the United States and those from
other countries. Phyllodes tumors account for approximately
1% of all breast neoplasms.2
Mortality/Morbidity
Because of limited data, the percentage of benign vs
malignant phyllodes tumors is not well defined. Reports
suggest, however, that about 85-90% of phyllodes tumors are
benign and that approximately 10-15% are malignant.3
Although the benign tumors do not metastasize, they have a
tendency to grow aggressively and can recur locally. 2Similar
to other sarcomas, the malignant tumors metastasize
hematogenously. Unfortunately, the pathologic appearance
of a phyllodes tumor does not always predict the neoplasm's
clinical behavior; in some cases, therefore, there is a degree
of uncertainty about the lesion's classification. The
characteristics of a malignant phyllodes tumor include the
following:
1. Recurrent malignant tumors seem to be more aggressive
than the original tumor.
2. The lungs are the most common metastatic site,
followed by the skeleton, heart, and liver.
3. Symptoms from metastatic involvement can arise from
as early as a few months to as late as 12 years after the
initial therapy.
4. Most patients with metastases die within 3 years of the
initial treatment.4
5. No cures for systemic metastases exist.
6. Roughly 30% of patients with malignant phyllodes
tumors die from the disease.
Race
A racial predilection does not appear to exist for phyllodes
tumors.
Sex
Phyllodes tumors occur almost exclusively in females. Rare
case reports have been described in males.
Age
Phyllodes tumors can occur in people of any age; however,
the median age is the fifth decade of life.
Some juvenile fibroadenomas in teenagers can look
histologically like phyllodes tumors; however, they behave in
a benign fashion similar to that of other fibroadenomas.
Clinical
History
1. Patients typically present with a firm, mobile, wellcircumscribed, nontender breast mass.
2. A small mass may rapidly increase in size in the few
weeks before the patient seeks medical attention.
3. Tumors rarely involve the nipple-areola complex or
ulcerate to the skin.
4. Patients with metastases may present with such
symptoms as dyspnea, fatigue, and bone pain.
Physical
1. A firm, mobile, well-circumscribed, nontender breast
mass is appreciated.
2. Curiously, cystosarcoma phyllodes tends to involve the
left breast more commonly than the right one.
3. Overlying skin may display a shiny appearance and be
translucent enough to reveal underlying breast veins.
4. Physical findings (ie, the occurrence of mobile masses
with distinct borders) are similar to those of
fibroadenoma.5
5. Phyllodes tumors generally manifest as larger masses
and display rapid growth.
6. Mammographic findings (ie, the appearance of round
densities with smooth borders) are also similar to those
of fibroadenoma.
7. Recurrent malignant tumors seem to be more aggressive
than the original tumor.
8. The lungs are the most common metastatic site,
followed by the skeleton, heart, and liver.
9. Symptoms from metastatic involvement usually arise in a
few months but may occur as late as 12 years after the
initial therapy.
10. Most patients with metastases die within 3 years of the
initial treatment.4
11. No cures exist for systemic metastases.
12. Roughly 30% of patients with malignant phyllodes
tumors die from the disease.
Causes
The etiology of cystosarcoma phyllodes is unknown.
Differential Diagnoses
Angiosarcoma
Breast Cancer
Other Problems to Be Considered
Juvenile fibroadenoma
Giant fibroadenoma
Inflammatory carcinoma
Sclerosing adenosis
Radial scar
Fat necrosis
Fibrocystic change
Breast abscess
Adenocarcinoma
Mastitis
Workup
Laboratory Studies
No specific hematologic tumor markers or other blood tests
can be used to diagnose cystosarcoma phyllodes.
Imaging Studies
Although mammography and ultrasonography generally are
important in the diagnosis of breast lesions, they are
notoriously unreliable in differentiating benign cystosarcoma
phyllodes (CSP) from the malignant form of the condition or
from fibroadenomas. Thus, findings on imaging studies are
not definitively diagnostic of CSP.6
Procedures
1. Fine-needle aspiration for cytologic examination usually
is inadequate for the diagnosis of phyllodes tumors.Core
biopsy is more reliable, but there still can be sampling
errors and difficulty in distinguishing the lesion from a
fibroadenoma.
2. Open excisional breast biopsy for smaller lesions or
incisional biopsy for large lesions is the definitive
method for diagnosing phyllodes tumors.
Histologic Findings
All phyllodes tumors contain a stromal component that can
vary significantly in histologic appearance from one lesion to
another. In general, benign phyllodes tumors demonstrate a
markedly increased number of regular fusiform fibroblasts in
the stroma. Occasionally, highly anaplastic cells with myxoid
changes are observed. A high degree of cellular atypia, with
increased stromal cellularity and an increased mitotic
count, is almost always observed in the malignant form of
cystosarcoma phyllodes. Ultrastructurally, in the benign and
malignant forms of phyllodes tumors, nucleoli may reveal a
coarsely meshed nucleolonema and abundant cisternae in
the endoplasmic reticulum.
Treatment
Surgical Care
In most cases of cystosarcoma phyllodes, perform wide local
excision, with a rim of normal tissue. 7,8,9 No absolute rules on
margin size exist. However, a 2 cm margin for small (<5 cm)
tumors and a 5 cm margin for large (>5 cm) tumors have
been advocated.
The lesion should not be "shelled out," as might be done with
a fibroadenoma, or the recurrence rate will be unacceptably
high.4
1.
If the tumor to breast ratio is sufficiently high to
preclude a satisfactory cosmetic result by segmental
excision, total mastectomy, with or without
reconstruction, is an alternative.
2. More radical procedures are not generally warranted.8
3. Perform axillary lymph node dissection only for clinically
suspicious nodes. However, virtually all of these nodes
are reactive and do not contain malignant cells. 10
Consultations
Consult a general surgery specialist.
Medication
There is no proven role for adjuvant chemotherapy or
radiation therapy in the treatment of phyllodes tumors.
Response to chemotherapy and radiotherapy for recurrences
and metastases has been poor, and no success with
hormonal manipulation has been documented.
Follow-up
Further Outpatient Care
1. Although specific guidelines regarding follow-up care
for phyllodes tumors are limited because of the rarity of
these lesions, regular, long-term follow-up care should
be performed to detect possible local recurrences.
2. An initial visit 1-2 weeks after surgery to detect any
initial complications should be followed by periodic visits
as determined by the patient's surgeon. A reasonable
schedule might be physical examinations every 6 months
and mammograms yearly for at least 5 years
(seeComplications).
3. Carefully observe patients for any possible recurrence.
Complications
As
with
most
breast
surgery,
postoperative
complications from the surgical treatment of phyllodes
tumors include the following:
o Infection
o Seroma formation
o Local and/or distant recurrence
Prognosis
1. Although cystosarcoma phyllodes is considered to be a
clinically benign tumor, the possibility for local
recurrence following excision always exists, particularly
with lesions that display malignant histology.9,11Tumors
that, after initial treatment by wide local excision, recur
locally should ideally be treated with total mastectomy.
2. Metastatic disease is typically observed in the lung,
mediastinum, and skeleton.
3. The clinical course is variable.
o If the tumor is benign, the long-term prognosis
is excellent following adequate local excision.
o If the tumor recurs locally after excision, further
local excision or total mastectomy is typically
curative.