Masses in Breast: What’s Good, What’s Bad, What’s What?! (Benign Breast Masses)

Assessing and demonstrating clearly an area of concern on our images is a long way from diagnosing disease. What is missed or obscured on our clinical images is not analyzed by the Radiologist. Therefore it is essential that we recognize a possible concern and know how to demonstrate it clearly.

Masses arise in the breast tissue for a variety of causes. Many breast lumps and masses are benign and triggered by normal physiological function of the breast organ. Some masses in the breast tissue can turn out to be dangerous malignant clumps of cells rapidly growing and consuming breast tissue. To demonstrate breast masses we first must appreciate their presence and then comprehend their characteristics.

The Characteristics of Benign Breast masses:

CHARACTERISTIC	PROPERTIES
Shape	Round Oval Lobulated
Borders	Smooth/Regular Haloed Circumscribed
Density	Homogeneous Mixed with Fat and Parenchyma
Size	Feels <or= to Appearance
Affect on Surrounding Parenchyma	Mass Displaces Surrounding Tissues
Associated Calcifications	Large Chunky Around Edge Central Few in Number
Secondary Signs of Ca.	Not Present

Benign Breast Masses:

Varieties of Benign Breast Masses Include:

1. Cyst: smooth, moderate to high opaque center, with a lucent halo
2. Lipoma: smooth, lucent center, circumscribed
3. Fibroadenoma: smooth, moderately dense center, with a lucent halo
4. Fibroadenoma/Lipoma: smooth, mixed lucent & moderately dense center, with a ‘pencil-line’ border surrounded by a lucent halo
5. Oil Cyst: smooth, very dark gray homogenous lucent center, sharply delineated opaque border
6. Fat Necrosis: Often asymmetrical borders with rough edges, centers are mixed chunky large calcification and lucent fat.

CYST appears as a smooth round, oval or lobulated mass which is displacing the surrounding parenchyma. The center of the cyst is denser than the surrounding breast tissue. The cyst is well delineated and bordered by a lucent halo of fat.

LIPOMA appears as smooth regular shaped mass which is displacing the surrounding breast tissue. The center of the lipoma is equal to density of the existing fat inside the breast. The lipoma is outlined with a pencil thin opaque line. If the lipoma is situated inside the fat of the breast, it is sometimes difficult to recognize.

FIBROADENOMA is seen as a smooth round oval or lobulated mass which displaces the adjacent breast tissue. The center of the fibroadenoma is moderately dense, usually about equal density as the breast’s own parenchyma. The fibroadenoma is well defined and outlined with a lucent halo of fat.

FIBROADENOMA/LIPOMA presents as a smooth regular shaped well defined mass displacing the surrounding parenchyma. The center of a fibroadenoma/lipoma is mixed lucent fat equaling the density of the breast fat and moderately dense tissue usually just slightly denser than normal parenchyma. The fibroadenoma/lipoma is delineated with an opaque pencil line surrounded by a lucent halo.

OIL CYST presents as a regular shaped smooth mass that is not always completely distinct within the tissue. The oil cyst is filled with oily fluids caused by the body’s reaction to a trauma. This oil is very homogenous and appears very dark gray on the radiograph. The oil cyst is encircled by a thin opaque line that follows the injury site and therefore is not always completely distinguished.

FAT NECROSIS is caused by serious trauma to the breast tissue usually through surgical intervention or significant accident. It therefore tends to follow the scar beds in the breast and is not regular or smooth. A section of fat necrosis in the breast is filled with dead cells and oily fluids intended to heal the tissue. So, the central portion of fat necrosis is a mixture of large chunky calcified dead cellular material a homogenous gray fat. In its early post-op or post-trauma state it is difficult to determine whether the mass is fat necrosis or disease.

SUMMARY

All masses and indeterminate lesions seen on our breast images should be noted, located and well demonstrated by today’s Mammographer. We should be well versed in the procedures of clarification and follow-up for such abnormalities. Coned compression views, lateral projections and ultrasound are the primary techniques used to further analyze masses. These views afford a clearer appreciation of the morphology and characteristics of the masses thus allowing the Radiologist to make informed diagnostic decisions.

The Mammographer within today’s modern team oriented department must have the advanced positioning and clinical skills to ensure the area of concern is appropriately imaged, clearly seen and able to be characterized by the Radiologist.