Reasons for delays in getting your biopsy and cytology test results

The uncertainty you feel while waiting for biopsy and cytology test results can cause a lot of stress and anxiety. Not knowing when the results will be ready and not understanding why testing sometimes takes longer than expected can cause extra concern.

Routine biopsy and cytology results may be ready as soon as 1or 2 days after the sample gets to the lab. But there are many reasons some take much longer to complete.

Processing time

Often, there are technical reasons for delays in reporting results. For instance, certain types of body tissues take longer to process than others. Bone and other hard tissues that contain a lot of calcium need special handling. These tissues must be treated with strong acids or other chemicals to remove the minerals so that the tissue becomes soft enough to be thinly sectioned (sliced). This takes extra time. Another technical reason for delay is that the formalin solution used for preserving tissues takes longer to penetrate samples with lots of fatty tissue (such as breast biopsies). So, an extra day of fixation (formalin treatment) is sometimes necessary. Large samples, such as when an entire organ is removed, might also require more than one day for the formalin to soak into the tissue. If formalin does not penetrate the sample completely, cells might not be clear under the microscope and testing is more difficult and/or less accurate.

Need to look at more tissue

For most large samples, only selected areas are processed and examined under the microscope. After the first sections of tissue are seen under the microscope, the pathologist might want to look at more sections for an accurate diagnosis. In these cases, extra pieces of tissue might need processing. Or the lab may need to make more slices of the tissue that has already been embedded in wax blocks. Either case can add 1or 2 days to the testing time.

Special stains or tests

Although most cancers can be found by looking at routinely stained sections, sometimes special stains or other tests may be needed to make an accurate diagnosis. For example, histochemical or immunohistochemical stains usually delay results for another day. Other advanced tests like flow cytometry, electron microscopy, and molecular genetic tests can take even longer, sometimes days, before results are ready.

Getting a second opinion

Another important reason for delaying a pathology report is that the pathologist may want to get a second opinion from an expert. Unlike some chemical tests done in the lab to measure the amount of a specific substance or to look at whether a substance is present or absent, testing tissue or cell samples for cancer is based on the professional opinion of the pathologist who looks at the sample under the microscope.

Although the abnormal features of some cancers are obvious, some have features that are very hard to recognize. Also, pathologists are often reluctant to diagnose certain very rare types of cancer without getting a second opinion from an expert who specializes in that area. There are pathology experts specializing in almost every organ system (digestive, head and neck, breast, bone, reproductive, etc.). When hard or rare cases come up, slides are usually sent to experts by overnight mail or as digital images. This review can delay the report for several days.

Other reasons

Finally, patients should realize that delays might occur for reasons that are neither technical nor medical. For example, entering the report into the computer takes time. Some labs send results right to doctors’ office computer systems or fax machines, but a hospital mail system or US mail is still often used and can delay the results.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: March 30, 2015 Last Revised: July 30, 2015

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