BENIGN
FIBROADENOMA, INTRACYSTIC PAPILLOMA
Fibroadenomas are the second most common form of breast disease and the most common breast mass. The peak incidence is from 20 through 25 years, with most patients younger than 30 years of age. More rapidly growing tumors may be found during adolescence. The tumors are twice as common in blacks (30% of breast complaints), in patients with high hormone states (adolescence, pregnancy), and in patients receiving unopposed estrogen therapy.
Fibroadenomas are generally
discovered as firm, painless, mobile, rubbery, solitary breast masses that may
grow rapidly during adolescence or in high-estrogen states such as pregnancy
or estrogen therapy. These tumors are generally discovered incidentally or
during breast self-examination and average 2 to 3 cm in diameter, though they
may grow as large as 6 to 10 cm. Multiple fibroadenomas are found in 15% to 20% of
patients, and they are bilateral in 10% to 20% of patients.
The chief symptom is gradual
enlargement of the mass over a period of months or years, the average duration
being just under 3 years. On palpation, the tumor is firm, encapsulated,
nodular, and freely movable. Mammography is generally avoided but can be
diagnostic if needed. Breast ultrasonography can distinguish between solid and
cystic masses, although it is often not required.
The structure of the tumor is
lobular. A centrifugal nodule with sharply circumscribed, fleshy, and
homogeneous character, usually spherical or ovoid in shape, characterizes them.
Pink or tan-white fibrous whorls bulge from the surface when cut. Hemorrhagic
infarcts are common. Microscopically, well-developed ducts are seen, surrounded
by a marked overgrowth of periductal connective tissue. When this connective
tissue is pale staining and loose, and the epithelium of the ducts is
compressed, the tumor is referred to as an intracanalicular myxoma. When the
amounts of fibrous tissue and duct growth are more evenly balanced, the tumor is
termed a fibroadenoma.
In early adolescence, in pregnancy,
or toward the menopause, when estrogen secretion is increased or dominant, the
growth of fibroadenomas is more rapid. These are termed giant mammary myxomas.
Malignant change is extremely rare and usually takes the form of fibrosarcoma
occurring in the giant myxoma. After menopause, fibroadenomas tend to regress
and become hyalinized but may remain unchanged or grow with estrogen
replacement therapy. The treatment is simple excision, which confirms the
diagnosis and suffices for the cure.
Benign intracystic papillomas are
soft epithelial growths occurring within a mammary duct or cystic acinar
structure. They are about one-half as common as fibroadenomas and are usually
found at or near the menopause, in the central zone of the breast. The duration
of symptoms is variable, usually from 6 months to 5 years. The symptoms consist
of either a sanguineous discharge from the nipple (in 50% of the cases) or a
lump associated with moderate tenderness. The tumors are rarely of large size;
they range in diameter from 1 to several centimeters. The larger ones are
associated with either retained bloody fluid within the cyst
or malignant change, which occurs in about 10% of the cases. Multiple
papillomas in one or both breasts are found in 14% of the cases. On palpation,
the benign papilloma is freely movable, soft, and either tense (cystic) or
fluctuant.
Grossly, intracystic papillomas are
encapsulated tumors in which epithelial tufts extend within the cavity and are
bathed by varying amounts of serous or sanguineous
fluid. Smaller papillomas may be found in the neighboring ducts or through the
ramifications of a group of ducts some distance from the main tumor. Microscopically,
the arborescent epithelial outgrowths rest upon a fibrous stalk with an intact
basement membrane. The treatment is simple excision, examination of the
neighboring ducts for secondary papillomas, and excision of these where
indicated. Recurrent tumors in elderly
patients warrant simple mastectomy.
