What is a pathology report?

A pathology report is a written medical record of a tissue diagnosis. A tissue diagnosis is the diagnosis made when a piece of tissue is examined by a pathologist, a doctor who is trained to examine tissue. He or she interprets the findings in tissue and makes a diagnosis. More than anything else, the pathology report dictates the management of a cancer and greatly impacts the management of other diseases.

Who is a pathologist?

A pathologist is a medical doctor who trains at least four years after graduating from medical school in how to examine tissue and make tissue diagnoses. Most pathologists train more than four years and specialize in making diagnoses in different areas of human disease. For instance, breast tissue may be examined by a pathologist specializing in surgical pathology and breast pathology.

What kinds of tissue do pathologists examine?

Pathologists are trained to examine tissue that may be as small as a dozen cells. Usually tissue is removed by a surgeon, a radiologist or another physician and sent to pathology for examination. Tissue can be cells taken by fine needle aspiration, a small core needle biopsy, a larger piece of tissue that is meant to remove a lesion or a very large piece of tissue that is a whole organ such as a whole breast or a lung.

How do pathologists examine tissue?

Pathologists examine tissue at two levels. First, the pathologist examines the tissue with his/her eyes and fingers to find abnormalities. If the piece of tissue is large, the pathologist will cut it into many slices so s/he can find small lesions that may be hidden in the tissue. The pathologist looks and feels for parts of the tissue that are abnormal. She or he looks at the location of the abnormalities and how far a lesion is from the edges of the tissue specimen. The edges are called "margins". For very small tissue samples, all of the tissue is processed to make microscopic slides. For larger tissue samples, the pathologist selects the parts of the tissue that looks and/or feels abnormal as well as some of the normal tissue for processing to make microscopic slides. Most of the time, the pathologist can make a diagnosis based on this first level of tissue examination. However, the pathologist confirms a diagnosis by examining sections under a microscope to make a final or microscopic diagnosis.

What are the types of tissue that pathologists examine?

Tissue removed for pathologic diagnosis fall into two general categories: Tissue that is removed to make a diagnosis but not to treat a lesion is called a biopsy. Biopsies can be very small pieces of tissue such as those obtained with a needle or they can be larger with stitches needed to close the hole left from removing the tissue. Tissue removed to treat a lesion is called a resection. Usually resections are large pieces of tissue, sometimes a whole body part such as a stomach, large bowel or a breast. Sometimes a piece of tissue is removed both to make a diagnosis and to treat the lesion. A breast lumpectomy may both remove and diagnose a lesion causing a mass.

What are the types of biopsies?

Common types of biopsies are:

Fine needle aspirations: Cells from a lesion are sucked out through a small needle and placed on a slide. This form of biopsy can identify malignant cells but not whether the lesion is invasive or in situ.

Core needle biopsies: tissue is cut out of a lesion by a large needle. The tissue is called a core because it is the size and shape of the inside of the needle used to obtain the tissue.

Core biopsies are completely submitted for microscopic examination. Most often core biopsies only remove part of a lesion.

Wire or needle localization biopsy or excision: This procedure is used when a lesion cannot be felt. A radiologist places a very thin wire next to or through the lesion to guide the surgeon who removes the lesion. The procedure is most commonly done for breast lesions. The radiologist obtains an image of both the breast and the piece of tissue removed. The tissue removed is usually large enough that the pathologist must slice up the tissue to look for abnormalities.

"_" -scopic biopsies: biopsies that are obtained through fiber-optic or rigid scopes that allow physicians to view the insides of the gastrointestinal track (stomach, esophagus, colon, called endoscopy), lungs (called bronchoscopy), urinary bladder (called cystoscopy), uterus (culposcopy) and upper airways (called laryngoscopy). Biopsies are obtained by special cutting pinchers and removed through the fiberoptic scope.

Incisional biopsy: This is a tissue sample in which a part of a lesion is removed by a surgeon. The lesion is well defined and there is a high clinical suspicion that the lesion is cancer. The tissue is taken only to establish a diagnosis and perhaps to perform special tests that help determine what therapy would be appropriate.

Excisional biopsy: This is tissue that is a complete lesion such as a mass in which a pathologic diagnosis has not already been made. This type of biopsy combines both treatment and diagnosis.

The second type of tissue samples are larger pieces of tissue that are removed for treatment of a lesion and/or for staging of a cancer. Again some large tissue samples are removed both to establish a diagnosis and to treat and stage a cancer. These larger tissue samples require that the tissue be examined to detect the lesion, then to stage a lesion, and then to determine whether the lesion is completely removed. The pathologist will determine how much of the tissue will have to be examined under the microscope to make a diagnosis and in the case of cancer, stage the cancer. Below are some examples of large specimens:

Mastectomy: The entire breast is removed for treatment of a cancer or another lesion. There are various types of mastectomies. Some remove very little skin to help in breast reconstruction. Some remove lymph nodes with breast tissue.

Colectomy: A part or the entire colon is removed for treatment of a cancer or for treatment of an inflammatory condition.

Nephrectomy: The entire kidney is removed for treatment of a cancer or because the kidney no longer is functional due to infection or a long standing kidney disease.

How is tissue prepared for microscopic examination?

Tissue that is processed for microscopic sections must be stabilized (fixed), dehydrated, and then infused with a material that solidifies the tissue so extremely thin sections can be cut that can be examined under a microscope. Tissue samples that are for microscopic examination are first fixed. This means that all the cellular chemicals that would cause the tissue to disintegrate or degrade are stopped. The most common way to fix tissue is to put it in a chemical solution called formaldehyde. Once formaldehyde has fixed the tissue, water is removed from the tissue by chemicals such as alcohol. Once the water is removed, the tissue is infused with paraffin or plastic to make it firm enough so that very very thin slices can be cut to microscopic slides.

The tissue is cut into ultra thin slices by specially trained technologists who also stain the thin sections so that pathologists can examine the sections under the microscope.

How long does it take to exam and process tissue for microscopic examination?

Making microscopic slides from tissue can take from 4 to 48 hours depending on the type of tissue and the processed used. The shorter time period requires one technologist to devote his/her time entirely to one or two tissue samples.

Longer time periods allow the laboratory to organize the tissue according to size, type, and priority. Certain tissues require longer processing in order to produce good microscopic sections. Very small tissue samples require special handling to ensure that they are not damaged or destroyed by the processing needed to create microscopic slides. Most histology laboratories process hundreds of tissue samples each day and produce slides for pathologists to examine.

What if I have a cancer? What should be present in my pathology report that makes a Cancer diagnosis?

To make and confirm a cancer diagnosis, a pathologist must always look at microscopic slides of a lesion. If there is cancer, a pathologist will have another pathologist confirm the diagnosis. If only a tiny part of a cancer was sampled by your physician, (such as smears, scrapes, shaves, fluids, aspirates, or biopsies) the pathology report may only say that cancer is present. If more tissue was removed, there will be information in the report.

A pathology report should identify you correctly, with your name and at least one other unique identifier such as your birthdate or medical record number. The report will have the date that your tissue was collected and sent to pathology and a laboratory specimen number. The most important part of your pathology report is the Diagnosis, sometimes called Final or Microscopic Diagnosis. Your cancer diagnosis will be stated in that part. If your operation also treated your cancer, your pathology report also should contain a cancer summary. This summary puts together all the pathologic information about your cancer found from examining your tissue specimen. The summary should list the type of cancer, special features of the cancer and whether the cancer has spread outside the organ where it started. This information helps your physician and you to decide whether your cancer needs more treatment and what kind.

There are many different kinds of cancer. Carcinoma is a cancer of cells that cover or line organs such as lungs, stomach and colon; it is the most common type of cancer. Sarcoma is cancer of the structural parts of the body (bone, cartilage, muscle, etc). Leukemia and lymphomas are cancers of the blood and lymph system.

How badly a cancer may behave is usually stated as well, moderately or poorly differentiated or as grade 1, 2, 3 with grade 1 being the best. Stage, or how far a cancer has spread, is reported using the TNM staging system. T stands for tumor; numbers from 1 to 4 and letters a,b,c etc are used just like clothing sizes with T1a being the smallest size and most likely to be cured and T4c being a very large tumor that almost always needs additional nonsurgical treatment. N stands for lymph node spread and M for other cancer spread (metastatases) with numbering and letters starting with zero (being the best) and the higher the number or letter, the worse the spread. N0 (zero) means no lymph node metastasis. M0 (zero) means no metastatic disease.

Sometimes the cancer summary is not done because not enough tissue was removed to stage your cancer. Sometimes a clear diagnosis cannot be established on a tissue sample. The pathologist may have to request additional tissue, perform tests on the tissue, and/or request another pathologist to examine the tissue. The pathologist may also perform tests on your tissue (e.g., estrogen receptor activity on breast cancer tissue) to help determine what further treatment should be used.

If you have had more than one operation with tissue removed, the pathologist should review your prior pathology material before examining your newest tissue. This prevents mistakes being made in your diagnosis and staging. If your doctor removed a melanoma, and then another doctor removed more tissue, two different pathologists may have examined your tissue. If the second pathologist has not reviewed your first pathology report and slides, s/he may make an incorrect diagnosis or not properly stage your melanoma.

If small differences in your cancer type or stage might change your cancer treatment, you can ask to have your pathology materials reviewed by a pathologist who specializes in your type of cancer. Most large pathology practices automatically give cancers to specialists, but small pathology practices may not have specialists. Specialty review of your pathology may provide additional, useful information in planning your cancer treatment.

A pathology report gives the results of a tissue examination to your doctor. Pathology reports of tissue that has been removed for cancer should have information on the type, grade and stage of the cancer in order for you and your doctor to plan the best treatment. No physician can ethically treat a cancer until there is a pathologic diagnosis of that cancer.