Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may sometimes mean that it is cancerous or premalignant (likely to become cancer).

The Latin “adjuvans” means to help, particularly to reach a goal.

Treatment that is given in addition to the primary (initial) treatment. For breast cancer, surgery is usually considered the “primary” treatment, to remove the cancer, and chemotherapy, when given, would be called adjuvant therapy. If a cancer has progressed to a stage where it cannot be surgically removed, then chemotherapy might itself be the primary treatment.

Loss of feeling or awareness. A general anesthetic puts the person to sleep, using either gases that are breathed into the lungs, or with medicines given in the vein. A “local” anesthetic causes loss of feeling in a part of the body such as the breast without affecting consciousness. Some procedures on the breast are done using a combination of some sedating medications, and local anesthesia. This form of anesthesia is often called “twilight sleep”, or “monitored anesthesia care” (MAC). People who have undergone colonoscopy would typically have experienced this form of anesthesia; in most cases, there is no memory of the experience, even though you are not completely asleep.

The small darkened area around the nipple of the breast.

Not typical, not usual, not normal, abnormal. Atypical is often used to refer to the appearance of precancerous or cancerous cells.

A benign but abnormal type of cell growth in breast tissue, in which the cells lining the breast ducts become both heaped up on one another, and irregular in size and shape. Although this is not cancer, we know that in women who have such findings as seen on a biopsy, the risk for developing cancer in the future is higher. In fact, if this finding is seen on a biopsy done by just a needle, it is usually recommended that a larger (surgical) biopsy be done promptly, to be sure there is no cancer nearby.

Pertaining to the cavity beneath the junction of the arm and the body, better known as the armpit. This is where the lymph nodes that “drain” the breast tissue are, and in women with invasive breast cancer, it is usually recommended to sample some of these nodes to check for the possibility of spread beyond the breast itself. This information is used to determine the stage of the cancer.

Not cancer. Not malignant. A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place).

A human tumor suppressor gene, which produces a protein, called breast cancer type 1 susceptibility protein. It is found in the cells of breast and other tissue, where it helps repair damaged DNA, and destroy the cell when DNA can’t be repaired. If BRCA1 itself is damaged (mutation), the damaged DNA can let the cell duplicate without control, and turn into a cancer. Women who are BRCA1 + (positive) have a mutation in this gene, which disrupts the usually ability to prevent other random mutations during cell growth to evolve into a breast cancer.

A human tumor suppressor gene that normally acts to restrain the growth of cells in the breast and ovary but which, when mutated, may predispose to breast cancer and to ovarian cancer . BRCA2 mutations have also been discovered to be responsible for a significant fraction of early-onset prostate cancer. The first breast cancer genes identified were BRCA1 and BRCA2. Mutations of BRCA1 and BRCA2 account for about half of all cases of inherited breast cancer, but this is still only about 5% of all cases of breast cancer in the US. These tumors tend to occur in young women. BRCA1 and BRCA2 are usually not involved in breast cancer that is not hereditary.

A procedure in which a sample of a suspicious breast growth is removed and examined, usually for the presence of cancer. The sample is obtained through a needle or removed surgically.

Breast cancer is diagnosed with self- and physician-examination of the breasts, mammography, ultrasound testing, and biopsy. There are many types of breast cancer that differ in their capability of spreading to other body tissues (metastasis). Treatment of breast cancer depends on the type and location of the breast cancer, as well as the age and health of the patient. The American Cancer Society recommends that a woman should have a baseline mammogram between the ages of 35 and 40 years. Between 40 and 50 years of age mammograms are recommended every other year. After age 50 years, yearly mammograms are recommended.

A localized swelling, knot, bump, bulge or protuberance in the breast. Breast lumps may appear in both sexes at all ages. In women, the fear is usually of breast cancer but many breast lumps turn out, fortunately, to be due to benign conditions that can be successfully treated such as infection, trauma, fibroadenoma, cyst, or fibrocystic condition of the breast. However, no breast lump should be dismissed as benign until it has been checked by a physician.

Another word for cancer. For example, carcinoma can arise in the breast , colon, liver, lung, prostate, and stomach. Cancer that arises in the breast has specific treatment that is different from cancer that arises in another organ such as the colon or the lung. Nearly all cancers can be treated with the various modalities of surgery, chemotherapy, and radiation therapy, though the specific treatment combinations depend not only on the location of the cancer, but also on the stage of the cancer, the age of the patient, and other characteristics of the tumor itself. In breast cancer, we are learning ways to categorize cancers in ways that allow us to provide individualized treatment plans, based on specific “targets”, or weaknesses, for which we have specific medications that directly attack those targets.

Cancer that involves only the place in which it began and that has not spread. Carcinoma in situ is an early-stage tumor. It is like having cancer “seeds” that, although they have the potential to sprout into a full-fledged invasive cancer, they have not yet done so. Finding cancer in this earliest stage is really the best time to find it, because the treatment at this point essentially cures the cancer. Following a curative surgical excision, other treatments may be recommended, to decrease the possibility of having other cancer seeds develop and grow. See also DCIS. NOTE: This term can be confusing because it is used in two different situations, which are not the same. In the case of “lobular carcinoma in situ (LCIS)”, this does not even mean that you have “cancer seeds”, but only a predisposition to developing cancer in the future. Years ago, this finding WAS considered an early form of cancer, but we now know better.

1. In the original sense, a chemical that binds to and specifically kills microbes or tumor cells. The term chemotherapy was coined in this regard by Paul Ehrlich (1854-1915).
2. In oncology, drug therapy for cancer. Also called “chemo” for short. Chemotherapy is usually given into the veins, so that it travels throughout the entire body. For this reason, it is sometimes referred to as “systemic” therapy, because it can have an effect on cancer cells that might have spread to anywhere in the body. Most chemotherapy agents derive their effect on cancer cells by inhibiting the division of cells in one way or another. Since cancer cells are dividing more rapidly than most any other cells in the body, the effects on the cancer cells are greater than the effects on the normal cells. But rapidly dividing normal cells, such as hair cells, intestinal lining cells, and bone marrow cells (where new blood cells are produced) can also be affected.

Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.

A cyst is an abnormal, closed sac-like structure within the breast that contains a liquid, or semisolid substance. Cysts in the breast are almost always benign, but can mimic a cancer. They are often drained with a needle in the office, as part of the evaluation of a new breast lump, or abnormal mammogram.

The process of cutting apart or separating tissue as, for example, in the study of anatomy or in the course of a surgical procedure. In talking about breast cancer, this word is most often used when talking about removal of lymph nodes from under the arm, or armpit, or “axilla”. We use the term “axillary dissection” to describe the removal of the fatty tissue here. When lymph nodes are to be removed, it’s not like picking grapes out of jello, it’s more like scooping out all the jello (fatty tissue) that contains the grapes (lymph nodes), and then later the pathologist will carefully go through the tissue to find all the lymph contained there. For this reason, there is no set number of lymph nodes that will be removed, since it depends on several factors. The number may range from 5 up to 40, and sometimes more or less than this as well.

A passage or a tube with well-defined walls suitable for the conveyance of air or liquids, as the bile duct and the pancreatic duct. In the breast, this of course is the passage way for milk when it is produced in the lobules, and this is the site where the most common type of breast cancer arises.

A precancerous condition characterized by the clonal proliferation of malignant-looking cells in the lining of a breast duct, without evidence of spread outside the duct membrane to other tissues in the breast or outside the breast. DCIS is clearly the precursor (forerunner) of invasive breast cancer. This is evident from the sharing of clonal chromosome changes by DCIS and adjacent invasive cancers. In other words, invasive breast cancer evolves from DCIS. Also called intraductal carcinoma.
A simple analogy to understand DCIS is to think of it as “cancer seeds.” Just as a dandelion seed has the ability to take root, sprout, and spread in your lawn, so can DCIS take root, and “invade” into the surrounding tissue. As a seed, it hasn’t done yet what cancers do, that is, to invade into tissue, but we know it has all the potential to do so if left in place.

A growth factor that plays an important role in the regulation of cell growth, proliferation, and differentiation by binding to its receptor EGFR. It’s importance in breast cancer relates to it’s role in the uncontrolled growth of cancer by repeated cell division. Much research in treatment of cancer is currently focused on inhibiting the “receptor” where EGF attaches to the cancer cell wall. By blocking the receptor, a drug can theoretically prevent EGF from stimulating cancer cell growth.

Estrogen is a female hormone produced by the ovaries, and to a lesser degree by the adrenal glands, liver, and fat cells. Estrogen deficiency can lead to osteoporosis.

A protein present in breast and other cells that has an affinity for estrogen in the circulation. The binding of estrogen causes a change in the receptor shape which then turns on certain metabolic processes that stimulates cellular growth. While this is a good outcome in normal breast development, in cancer cells, many of which have increased numbers of estrogen receptors, the stimulation caused by estrogen can lead to enhanced cancer growth and spread. In newly diagnosed breast cancer, estrogen receptor (ER) is routinely measured in the cancer cells to help decide about certain treatment options. If the cancer is ER positive (+), treatment with estrogen blocking or inhibiting drugs is typically added to the overall treatment plan. Options include the use of an “aromatase inhibitor”, or tamoxifen.

Pertaining to the act of excision, of removal by surgery. An excisional biopsy is one in which the lesion is removed by the biopsy. From the Greek ektome meaning excision.

A biopsy in which an entire biopsy in which an entire lesion, is removed. A excisional biopsy is in contrast to an incisional biopsy in which only a sample of tissue is cut into (incised) and removed.

Radiation therapy using a machine to aim high-energy rays at a tumor in the breast (or other part of the body). You can think of it as like having a mammogram, except that the dose of radiation is much much higher.

A result that appears negative but fails to reveal a situation. An example of a false negative: a particular test designed to detect cancer of the breast is negative but the person actually has cancer. For screening mammography, it is important to know that not all breast cancers are seen. Another way of saying this is that mammography has a false negative rate of approximately 5-10%, meaning that out of every 100 women who actually have breast cancer, mammograms may not show it in 5-10 of the women. This is why we emphasize breast self-exams and annual physician breast exams in addition to mammography. Most women who might have a ”false negative” mammogram will have some other indication of the cancer on exam.

A result that is erroneously positive when a situation is normal. An example of a false positive: a particular test designed to detect breast cancer is positive but the person does not have breast cancer. For screening mammography, the false positive rate is actually quite high. Mammograms are usually classified by a BIRAD number, anywhere from 1-5. Those classified as “5” are highly suspicious for breast cancer, and nearly all of these will be “true positive”. Those classified as “4” are still suspicious, and biopsy is recommended, but only about 15% of these will be cancer. We would say that a BIRAD 4 mammogram is “positive”, but only about 1 in 6 women will actually have breast cancer. Ideally, we would not have to do that many biopsies to find the women who have cancer, but if don’t do the biopsies in this group, we won’t find the breast cancers as early as we would otherwise.

The family structure and relationships within the family, including information about diseases in family members. If there are a number of women in your family who have had breast cancer, or even one or two with breast cancer at a very early age, or have had both breast and ovarian cancer, you may be at risk for carrying one of the BRCA (breast cancer) genes. Breast cancer can “run in the family”, but only about 5% of breast cancers are clearly “in the family” based on genetic testing for BRCA.

A benign rubbery growth of tissue that is most commonly seen in teenagers and girls in their 20s. They can be multiple at times. Any “lump” in the breast can cause anxiety at any age, so it is no surprise that even if a doctor is confident that a lump is a fibroadenoma just based on its feel and perhaps by looking at it with ultrasound, they should nearly always be biopsied. Most of them are easily removed, and this may be the better option in many cases.

Testing a sample of blood (or another fluid or tissue) for evidence of a gene. The evidence can be biochemical, chromosomal, or genetic. The aim is to learn whether a gene for a disease is present or absent.

An educational counseling process for individuals and families who have a genetic disease or who are at risk for such a disease. Genetic counseling is designed to provide patients and their families with information about their condition and help them make informed decisions.

Tests done for clinical genetic purposes. Genetic tests may be done for diverse purposes pertaining to clinical genetics, including the diagnosis of genetic disease in children and adults; the identification of future disease risks; the prediction of drug responses; and the detection of risks of disease to future children.

A measure of how abnormal in appearance cancer cells are, graded 1-3. Some cancers are very similar from one cell to another, while others are quite variable and may have very bizarre shapes, and have very large nuclei. The more abnormally appearing cancers have a higher “grade”, and typically these higher grade cancers may be more aggressive than lower grade cancers.
It is easy to confuse “grade” with “stage”, but they are completely different. The grade of a cancer is a single factor among many characteristics that describe the cancer cells. In terms of determining what treatment combination should be used for each patient, the stage of the cancer is more significant.

A chemical substance produced in the body that controls and regulates the activity of certain organs. With regard to breast cancer, the most important hormone is estrogen. Progesterone plays a lesser role. Breast cells, both normal and cancerous, can have “receptors” on their cells that can interact with estrogen in the blood stream. There are some breast cancer treatments that work by blocking this interaction on the surface of the cells.

A sudden wave of mild or intense body heat caused by rushes of hormonal changes resulting from decreased levels of estrogen. Hot flashes can occur at any time and may last from a few seconds to a half-hour. They are due to blood vessel opening and constricting and are often a symptom of menopause. Hot flashes sometimes are caused, or increased, by the use of tamoxifen, an estrogen blocking drug used in women with estrogen receptor (ER) positive cancer.

A condition in which there is an increase in the number of normal cells in a tissue or organ. This is often seen on breast biopsies, and does not have that much significance, unless the hyperplasia is considered “atypical”. In this case, although there is no cancer, the risk for developing cancer in the future is increased.

Also see “carcinoma in situ”. In the normal location. An “in situ” tumor is one that is confined to its site of origin and has not invaded neighboring tissue or gone elsewhere in the body. In breast cancer, the term ductal carcinoma in situ (DCIS) is such an example. The “in situ” phrase means that we can tell for sure that these cells have the POTENTIAL to do their cancer thing (which means, to invade into surrounding tissue and eventually spread elsewhere), but that they have not yet invaded even the tissue right around the DCIS cells. You can think of these cells as “cancer seeds”, which haven’t yet sprouted, but have all the capability of doing so if left in place.

A cut. When making an incision, a surgeon is making a cut.

A biopsy in which only a sample of the suspicious tissue is cut into (incised) and removed for purposes of diagnosis. A incisional biopsy is in contrast to an excisional biopsy in which an entire lesion, usually a tumor, is removed.

Also called ductal carcinoma in situ. See: DCIS.

This term is frequently included as a descriptor of the breast cancer on the pathology report. It is important to know that this term does not carry any extra information other than another way of saying that it is cancer. So it is really kind of redundant. But the term is used to distinguish from the non-invasive cells that are seen sometimes seen, so called “cancer seeds (or intraductal cancer)”, in which case, there has not even been any “sprouting” of the cancer cells into surrounding tissues. Cancer cells which have “sprouted” into the surrounding tissues are called invasive, and this is the case even in the very earliest stages of breast cancer. So don’t think that this term carries any awful prognosis.

The surgical removal of a small tumor (a lump) which may or may not be benign (or malignant). Lumpectomy refers specifically to the removal of a lump from the breast.

An almost colorless fluid that travels through vessels called lymphatics in the lymphatic system and carries cells that help fight infection and disease. Cancer cells in the breast sometimes break off from the cancer “lump” in the breast and float along in the lymph, just like a hobo might jump on a train to get from one place to another, though the train was not intended to transport hoboes. The cancer cells can then potentially sprout and grow inside the lymph nodes at the “end of the line”, under the arm (axilla). It is for this reason that your surgeon will need to check some lymph nodes surgically to be sure there has been no spread.

Also sometimes referred to as lymph glands, lymph nodes are small rounded or bean-shaped masses of lymphatic tissue surrounded by a capsule of connective tissue . Lymph nodes are located in many places in the lymphatic system throughout the body. Lymph nodes filter the lymphatic fluid and store special cells that can bacteria or other “foreign” material traveling through the body in the lymph fluid. The lymph nodes are critical for the body’s immune response and are principal sites where many immune reactions are initiated. During a physical examination, doctors often look for swollen lymph nodes in areas where lymph nodes are abundant, including the neck, around the collarbone, the armpit ( axilla ), and the groin.
Cancer cells sometimes “hitch a ride”, like a hobo on a train, in the lymph system, and in this way can start growing inside lymph nodes. In breast cancer, this most likely will be seen in the lymph nodes under the arm, or axilla.

The tissues and organs, including the bone marrow, spleen, thymus, and lymph nodes, that produce and store cells that fight infection and disease. The channels that carry lymph are also part of this system.

Small thin channels similar to blood vessels that do not carry blood, but collect and carry tissue fluid (called lymph) from the body to ultimately drain back into the blood stream.

A common chronic, and at times, debilitating condition in which excess fluid called lymph collects in tissues and causes swelling (edema ) in them. This condition does not occur nearly so often today as it did in the last century. When it does occur, symptoms can range from very mild to very severe. Unfortunately, when it does occur, treatment options are limited to decreasing the severity through the use of massage techniques, compression garments, and the like.

Having the ability to invade into nearby tissue and spread (metastasize) to other parts of the body.

A x-ray of the breast using a device that compresses and flattens it. There are two basic mammogram tests — screening mammograms and diagnostic mammograms. A screening mammogram is the more basic exam, and is recommended on an annual basis after age 40, even if there are no symptoms related to the breast. A diagnostic test is used if there is some symptom, such as a lump, or localized tenderness, or nipple discharge, or if there was some vague abnormality seen on a screening mammogram. This test is a bit more involved, and may lead to other studies such as ultrasound. When a “diagnostic mammogram” is done, the radiologist usually interprets the studies right away, and you will likely receive a specific answer about the results before you leave the facility. For screening mammograms, the result is likely to be delayed a day or two, and the result will be available through your physician.

There is an entire page devoted to this relatively new way to give radiation therapy for breast cancer after lumpectomy, such that the treatment is given in just 5 days, two treatments each day.

In the treatment of breast cancer, the surgical procedure to remove the cancer in the breast should remove the entire lump of cancer and some normal breast tissue all around. This is not always as easy as it might seem, because sometimes there are microscopic roots or tendrils extending outward from the lump that is felt. The evidence of cancer cells on the outside of the removed tissue might only be seen after the pathologist has completed the microscopic exam a few days later. If cancer cells are seen on the outer surface of the tissue that’s been removed, this is called a “positive margin”. Although there are some exceptions, in most cases if there is a positive margin, another operation may be necessary to be certain no cancer remains in the breast, and so, to have an acceptably low risk for any cancer coming back in the breast in the future.

A general term for removal of the breast, usually to remove cancerous tissue. Drainage tubes are left in the surgical incision for a few days after the operation; these are removed when drainage has decreased sufficiently. After the mastectomy, reconstructive surgery may be performed to restore a more normal appearance. Some patients choose to avoid reconstructive surgery, and wear special undergarments instead.
The very first treatment that was found to treat breast cancer was a “radical mastectomy”, in the late 1800’s. This procedure removed not only the entire breast, but also the skin, and the muscles of the chest wall, and all the lymph nodes under the arm and clavicle. We no longer utilize this radical operation when a mastectomy is done. Sometimes we can even leave essentially the entire skin “envelope” of the breast, and then “re-fill” the skin envelope with whatever is being used for the breast reconstruction. This “skin-sparing” mastectomy typically provides a much more natural breast reconstruction.
The term “partial mastectomy” might also be used, which is not the same as a “mastectomy”. This term, partial mastectomy, is often used interchangeably for lumpectomy.

The time in a woman’s life when menstrual periods permanently stop; it is also called the “change of life.” Menopause is the opposite of the menarche.

The spread from one part of the body to another. When cancer cells metastasize and cause secondary tumors, the cells in the metastatic tumor are like those in the original cancer.

Pertaining to a single clone of cells, a single cell and the progeny of that cell. As opposed to polyclonal.

An antibody produced by a single clone of cells (specifically, a single clone of hybridoma cells) and therefore a single pure homogeneous type of antibody. Monoclonal antibodies can be made in large amounts in the laboratory and are a cornerstone of immunology. The term “monoclonal” pertains to a single clone of cells, a single cell and the progeny of that cell.

Literally a knot, a node is a collection of tissue. For example a lymph node, is a collection of lymphoid tissue. A nodule is a small node, a little collection of tissue.

This test is performed on tissue from the initial biopsy or lumpectomy specimen. It uses the unique genetic profile of each woman’s breast cancer to make an accurate prediction about whether the cancer will recur. It measures an array of genes that are known to be associated with more aggressive tumors. The test has been shown to be much more powerful than current predictive methods, which are based on “clinical staging”, which is based on the size of the tumor and the status of the lymph nodes

A tumor that is at the original site where it first arose. For example, a primary breast tumor is one that arose in the breast as opposed to one that arose elsewhere and metastasized (spread) to the breast. The original tumor is sometimes called “the primary.” It is rare for cancers that originate elsewhere to spread to the breast. Most cancers IN the breast are breast “primaries”. Breast cancer can and does spread to other organs. As it turns out, if a breast cancer is going to spread elsewhere, it seems to have a propensity for spreading to lymph nodes, lung, bones, liver, or brain more than anywhere else.

A female hormone and the principal progestational hormone that is made mainly by the corpus luteum in the ovary and by the placenta. Progesterone prepares the lining (endometrium) of the uterus (the womb) to receive and sustain the fertilized egg and so permits pregnancy. Similarly refers to synthetic versions of the hormone. Also known as progestational hormone. In the breast, cancer cells can have cell receptors that interact with progesterone in the blood stream. (Progesterone receptor [PR] positive). This has less significance than being “estrogen receptor +”.

An artificial substitute or replacement of a part of the body such as a tooth, eye, a facial bone, the palate, a hip, a knee or another joint, the leg, an arm, etc. A prosthesis is designed for functional or cosmetic reasons or both. In breast cancer disease, the term prosthesis usually refers to a padding worn inside the bra to restore the shapeliness of the breast after mastectomy, if a reconstruction has not been done.

The use of high-energy rays to damage cancer cells, stopping them from growing and dividing. Like surgery, radiation therapy is a local treatment that affects cancer cells only in the treated area. See also external (beam) radiation therapy.

The treatment of disease with ionizing radiation. Also called radiation therapy.

In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. In breast cancer, the most commonly discussed receptors are for estrogen and progesterone. To take an example, the receptor for estrogen, a molecule that acts as a messenger for the proliferation of breast tissue, is a unique harbor on the cell surface where estrogen docks. Without this receptor, or if a medication (eg, tamoxifen) is taken which blocks this receptor, estrogen cannot dock and cannot deliver its instructions to proliferate (go through cell division).

To occur again. To return. In breast cancer, after treatment has been completed, there is typically no sign of any cancer anywhere in the body. Even so, some women will later be found to have some of the same breast cancer growing again, either in the same area (local recurrence) or elsewhere (distant recurrence).

The return of a sign, symptom or disease after a remission. The reappearance of cancer cells at the same site or in another location is, unfortunately, a familiar form of recurrence.

Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.

A mammogram (a x-ray of the breast) in women who have no signs of breast cancer . It usually involves two x-rays of each breast. The aim of a screening mammogram is to detect a tumor that cannot be felt. Most mammography facilities have switched to “digital” mammography, just as most photographers have switched to digital cameras. The advantages are in ease of storage, and of manipulating the image for interpreting them. For example, the image can be made darker or lighter, or the black and white can be “inverted”, or the image can be greatly magnified. Use of digital mammography has simplified the process for the patient, since it is much less often necessary to do them over.

As regards cancer, the extent of a cancer, especially whether the disease has spread from the original site to other parts of the body. Doctors determine the size of the tumor in its original location, whether there is any cancer seen in the lymph nodes that are nearby, and whether there is any evidence of cancer that has spread from the original site to elsewhere in the body. We have an entire page devoted to breast cancer staging.
Another word used to describe cancer cells is the grade. It is very easy to confuse these two terms, so you might want to look at this definition as well, to be sure you don’t mix them up.

An abnormal mass of tissue. Tumors are a classic sign of inflammation, and can be benign or malignant (cancerous). There are dozens of different types of tumors. Their names usually reflect the kind of tissue they arise in, and may also tell you something about their shape or how they grow. For example, a medulloblastoma is a tumor that arises from embryonic cells (a blastoma) in the inner part of the brain (the medulla). Diagnosis depends on the type and location of the tumor. Tumor marker tests and imaging may be used; some tumors can be seen (for example, very advanced tumors of the breast) or felt (palpated with the hands). Cancer may be found when it is very small, and in such cases, cannot be felt. Although there is no “tumor” this would still be a cancer, if the cells show the typical cancer characteristics as visualized under the microscope.
The use of the word tumor is sometimes confusing, since it doesn’t always mean cancer.

A gene that protects a cell from one step on the path to cancer. When this gene is mutated to cause a loss or reduction in its function, the cell can progress to cancer, usually in combination with other genetic changes.

High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine the breast if a lump is felt, or if a density is seen on screening mammography. It is usually very good at telling the difference between a simple cyst, filled with fluid, and a solid mass of tissue. In addition, one can often tell the difference between benign tissue, such as a fibroadenoma, and a cancerous tissue, based on the ultrasound image.
Ultrasound is often used to help the doctor do a biopsy, as it allows a biopsy needle to be placed precisely in the lump.