Is it possible for a biopsy to provide misleading positive results? The chances of a biopsy test producing a false positive are small. Confirmatory tests, such as biopsies, are utilized following screens to confirm the identification of what an initial screening may reveal. These subsequent tests can be done at any time after the initial screen; however, they should be done within three months of the first test.
A false positive means that the test result indicates a disease or condition when there is actually no such thing. This could happen if the sample collected by the biopsy contains cells from another person, which would be indicated by a positive culture. Biopsies may also produce false positives if there is inflammation present in the body but no cancer. In this case, further testing would be necessary to determine if the disease identified is actually malignant. False positives are rare, but they do occur. They are usually due to confusion with another condition called a pseudopositive.
A true negative result does not indicate any disease or condition. A negative result would include cases where there was no tissue available for analysis, or where the analysis did not show signs of disease. A negative result would also include cases where the patient had cancer, but the test was done on samples taken before it grew enough to be visible. If your doctor tells you that you have cancer but the test results were negative, that would be considered a true negative result.
All medical tests have the potential to produce false positive and false negative results. A false positive can result in wasteful therapy, whereas a false negative can result in a mistaken diagnostic, which is extremely dangerous since a condition has been overlooked. Medical tests should be used with caution so that they do not cause more harm than good.
The likelihood of a test result being true depends on how well it predicts what will happen with patients. For example, if my patient has chest pain and an elevated cardiac enzyme level is found, this means their heart muscle is damaged. The test results are called "positive." They are accurate and reliable. It is important to remember that most test results are either positive or negative. A positive result means that something is wrong with your body. A negative result means that nothing is wrong with your body. Most tests only give one answer. When interpreting test results, it is important to understand what would happen with your patient if they had the opposite diagnosis or illness.
A false negative test result may lead to a delay in appropriate treatment. However, their illness may be serious, so physicians should consider other possible diagnoses before concluding there is no problem with the patient's heart.
A biopsy might be inconclusive, which indicates it did not give a definite conclusion. In this situation, the biopsy may need to be redone, or other testing may be necessary to confirm your diagnosis. If your doctor cannot conclude with certainty what is causing your symptoms, you will have to continue to have symptoms checked periodically for changes or growth of tumors.
Although tests aren't always 100 percent accurate, getting the erroneous response from a cancer biopsy—also known as a "false positive" or "false negative"—can be very upsetting. While data is scarce, it is commonly assumed that an inaccurate biopsy result occurs in 1 to 2% of surgical pathology cases. This means that if your surgeon takes one sample of tissue and reports that it contains cancer, then there is a less than 99% chance that the tissue actually holds no disease.
The cause of this error is usually due to sampling error. In other words, perhaps only a portion of the tumor was examined instead of the whole thing. This can happen because surgeons need to remove some piece of tissue to make sure that they have gotten all the cancer cells; however, even with multiple samples, some parts may go unnoticed.
Another reason for an incorrect report may be because someone misinterpreted what they saw on the microscope. For example, if a pathologist reported that cancer was found in a specimen but actually meant sarcoma instead, then this would also be considered a sampling error.
Finally, an inaccurate diagnosis might be caused by an error made by the lab reporting the results. Sometimes genetic tests come back with a response other than cancer or non-cancer. For example, a gene mutation may not be detected even though cancer exists because the mutation occurred at a location where the test wasn't able to identify it.