An Adenoma is the general name for a tumor (‘oma‘) which develops primarily from glandular tissue (adeno cells). An adenoma would be considered a ‘proliferative‘ neoplasm, and can create a good deal of concern that it might be carinoma, but they are considered benign. Adenomas can develop in many body organs, including the thyroid, the colon, and adrenal glands, (anywhere there are glands). But when it occurs in the breast it is generally called a ‘fibroadenoma‘, in reference to the combination of fibrous and glandular cells that characterize breast tissue. Though benign, there is some concern that over time adenomas could progress and become malignant, so they are taken quite seriously and followed closely. In the unlikely event that an adenoma becomes malignant, it would be referred to as ‘adenocarinoma‘.
Check out our new page on Adenoma – it has more up-to-date information. But just letting you know this page is still pretty good!
What causes an adenoma in the breast?
Adenomas usually form from secretion cells, which are themselves part of a category of cells called ‘epithelial cells‘. These cells tend to be found in the linings of organs, and in the skin. It is thought that an adenoma forms when the non-secreting epithelial cells grow excessively. An adenoma is really a disorganized (dysplasia) collection of fat cells, fibrous cells, and glandular (adeno) cells, and depending upon which of these elements seems to be most dominant, the name of the lesion may vary accordingly. A “Fibroadenolipoma” would likely indicate an adenoma of approximately equal amounts of fibrous, glandular, and fat (lipo) cells.
How is a breast adenoma usually discovered?
Breast adenomas are not easy to detect. It often takes a combination of biospy samples and X-ray and ultrasound images.
The microscopic image of a breast adenoma above is predominately composed of fibrous tissue, so it would likely be called a fibroadenoma. In addition to the ‘atypia‘ or atypical mix and configuration of the fibrous, glandular, and fat cells, adenomas sometimes have irregular cells with hyperchromatic (various colors) nuclei, pseudo-stratified nuclei, some mitosis (cell division) and reduced mucosecretion. When the glandular cells tend to form into distinct ‘tubule‘ shapes, the lesion is usually termed ‘tubular adenoma‘, which has some of it’s own unique characteristics.
Mammograms show a mixture of fat and solid
Mammogram and ultrasound images of a breast adenoma will tend to show a mixture of solid elements and fat elements. (Fat tissue often appears ‘lucent‘ or see-through on an X-ray), and it will typically have a well defined, smooth border. But since there are obvious ‘solid‘ elements (neoplastic cells) which could be indicative of breast cancer, a biopsy is almost always undertaken.
Other common breast adenomas
Additional sub-types of adenomas associated with the breast include the ‘lactating adenoma‘, which is related to hormonal imbalances in pregnancy and lactation, and ‘nipple adenoma‘ which is essentially an otherwise normal adenoma rowing beneath the nipple, which can cause complications and discharges.
Pleomorphic adenoma cells show similarity to parotid gland cells
Then there is the rare possibility of a ‘pleomorphic adenoma‘, which is a tumor usually associated with the salivary glands. Pleomorphic adenoma of the breast is simply a kind of breast epithelial-cell growth with very similar morphological features to pleomorphic adenoma of the parotid gland (in the mouth), and with many ‘pleomorphic‘ (many shaped) cell formations. It also tends to develop below the nipple.
Are breast adenomas a cause of concern for breast cancer?
Adenomas are benign, but can cause complications when they occur in the breast due to the compression of breast ducts (sometimes called a ‘mass effect’), and they can stimulate the production or large amounts of somewhat unregulated hormones (sometimes called ‘paraneoplastic syndrome‘)
In terms of treatment, if there are no symptoms or complications they are often they are just left alone. If there are complications or the adenoma grows to a size that it can impair breast function, then they may be surgically removed. Though an adenoma forms in a similar way to a cancerous tumor, they only involve cells native to the area, and they do not metastasize.
Adenomas can ‘develop’ into malignancies, if a slow developing breast carcinoma is already present.
Sometimes, however, adenomas develop into malignancies. It’s usually not a case of cells involved in the adenoma somehow changing into malignant cells, but rather, the breast carcinoma may be present and developing at a slower rate alongside the other elements of the adenoma. If and when this happens, the newly malignant adenoma is called an adenocarcinoma. So, the screening physicians tend to be very careful and thorough in ruling out breast cancer. On the whole, breast carcinomas do not typically develop from adenomas, though this is possible in some other adenomas in other areas of the body.
Everything you pretty much need to know about breast adenoma is all listed above, but let’s go over a few common questions and answers anyhow…
- What causes breast adenoma? They usually come from secretion cells, which are a category of epithelial cells. They are found in the linings of the organs and in the skin as well.
- What does breast adenomas look like? They are usually round with distinct borders, they are easily moved, firm or rubbery, and usually painless.
- What are some of the breast adenoma tests/diagnosis? Diagnostic mammography, breast ultrasound, fine need aspiration, or core needle biopsy.
- What is the recommended treatment/drugs? In many cases, breast adenoma requires no treatment, although, some women choose to have it surgically removed for their peace of mind. If your doctor is certain that your breast lump is a breast adenoma, based on the results of the clinical breast exam, imaging test and biopsy, you may not need surgery. However if you do need surgery, procedures include a lumpectomy or excisional biopsy, or a cryoablation.
- Why might I decide to avoid surgery? Surgery can distort the shape and texture of the breast, breast adenoma can sometimes shrink or disappear on their own, and the breast has multiple fibroadenomas that appear to be stable (no changes in size on an ultrasound compare red to an earlier ultrasound.
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- Hayashi Y; Kawamoto H; Sasao T; Nagusa Y; Iwamori S. , Adenoma of the breast: histopathological study of 9 cases.Gan No Rinsho. 1988; 34(1):33-40