FIBROCYSTIC CHANGE
II—ADENOSIS
Stromal and ductal proliferation that results in cyst formation, diffuse thickening, cyclic pain, and tenderness are the hallmarks of fibrocystic change. The term fibrocystic change encompasses a multitude of different processes and older terms, including fibrocystic disease. It is the most common of all benign breast conditions, accounting for its linguistic demotion to change from the designation disease. To one extent or another, fibrocystic change affects 60% to 75% of all women. These changes are most common between the ages of 30 and 50 years, with only 10% of cases in women younger than 21 years. Methylxanthine intake has been proposed as a causative agent, but hard data are lacking. There is no evidence that oral contraceptives increase the risk of these changes. A family history of fibrocystic change is often present, but causality is difficult to establish.
The cause or causes of fibrocystic
change are unknown, but it is postulated to arise from an exaggerated
parenchymal response to hormones. A role for progesterone has been suggested
based on the common occurrence of premenstrual breast swelling and tenderness.
Other proposed sources for fibrocystic changes are altered ratios of estrogen
and progesterone or an increased rate of prolactin secretion, but none of these
has been conclusively established.
Adenosis is characterized by the
occurrence in one or both breasts of multiple nodules varying from 1 mm to 1 cm
in size, usually distributed about the periphery of the upper or outer
hemisphere. The breasts affected tend to be small, dense, and edged like a
saucer when grasped in the hand. Typical findings on physical examination
include multiple cysts and nodules intermixed with scattered bilateral
nodularity, or a ropy thickening, especially in the upper outer quadrants of
the breast. Pain and tenderness (which vary during the menstrual cycle) occur
as in mastodynia, with the worst symptoms occurring just before menses. (The
pain associated with fibrocystic change often radiates to the shoulders or upper
arms.) Although pain is the most common com- plaint, up to 50% of cases of
fibrocystic adenosis may be asymptomatic.
Fibrocystic changes appear in three
steps: (1) proliferation of stroma, especially in the upper outer quadrants;
(2) proliferation of the ducts and alveolar cells occurs, adenosis ensues, and
cysts are formed; and (3) larger cysts are found and pain generally decreases.
Proliferative changes may be extensive (although usually benign) in any of the
involved tissues. Overall, the mammary tissue affected contains dense fibrous
tissue, numerous minute cysts, and foci of epithelial proliferation. Lobule
formation is much distorted. Some of the terminal tubules form solid plugs of
basal cells, which, on cross section, appear as duct adenomas. Other tubules
lead to greatly enlarged lobular structures, which are penetrated by dense
strands of fibrous tissue giving the appearance of fibrosing adenoma.
Dif-ferential diagnosis of adenosis from fibrosing adenoma is sometimes difficult, if not impossible,
particularly if small, intraductal papillomas have developed in advanced cases
of adenosis. Premenopausal age, multiplicity of more peripherally situated
nodules, a brownish rather than a sanguineous discharge from the nipple, and
the involvement of both sides of the breast favor adenosis.
Mammography may be used to assist
with the diagnosis or to provide a baseline, but it is not necessary for
diagnosis. Mammography is more difficult in younger women who predominantly have these complaints.
As a result, ultrasonography may be of more help when imaging is deemed
necessary. If the patient has a cystic breast mass, needle aspiration with a
22- to 25-gauge needle may be both diagnostic and therapeutic. Fine needle
aspiration or core biopsy may be required if malignancy is suspected. When
atypia is found in hyperplastic ducts or apocrine cells, there is a fivefold
increase in the risk of development of carcinoma in the future.
