What Is Histopathology?

Expertise, specialities, and training

The National Cancer Institute defines histopathology as "the study of diseased cells and tissues using a microscope." Histology is the study of tissues, and pathology is the study of disease. So taken together, histopathology literally means the study of tissues as relates to disease.

A histopathology report describes the tissue that has been sent for examination and the features of what the cancer looks like under the microscope. A histopathology report is sometimes called a biopsy report or a pathology report.

female doctor looking in microscope
Hero Images / Getty Images

Histopathology Reports

The specialist doctor who does the examination under the microscope is called a pathologist. The tissue that is studied comes from a biopsy or surgical procedure whereby a sample of the suspect tissue is selected and sent to the laboratory.

It is then processed and cut into very thin layers (called sections), stained, and examined under microscopes to characterize the details of the cells in the tissue.

For some diseases, the surgeon can get a sample of the tissue interpreted very quickly through the use of frozen sections. Frozen sections or slices are used sparingly in lymphoma, however, due to problems in interpretation and sampling.

In lymphomas, lymph nodes are the tissue most commonly examined in histopathology. For many types of blood cancers, a bone marrow biopsy may also be required for a definitive diagnosis.​

Components of a Histopathology Report

Histopathology reports on surgical cancer specimens are getting more and more complex. They may include:

  • The microscopic appearance of the involved tissue
  • Special stains
  • Molecular techniques
  • Other tests

Molecular techniques refer to the ability to analyze cells and tissues at the molecular level, which is at the level of proteins, receptors, and the genes that code for these things.

Interpreting the Histopathology Report

Many of the findings from such examination of the tissues are linked to prognosis. Prognostic indicators may include tumor grade and extent of spread, and whether or not the cancer was removed with a margin of healthy cells surrounding it, or if there is evidence the cancer has spread beyond what was removed.

Grading systems differ depending on the kind of cancer being graded, but generally, the cells are scored based on how abnormal they appear under the microscope, with Grade 1 tumors being more normal looking and Grade 4 tumors reflecting more abnormalities.

A high-grade tumor, then, is generally one in which the cells have more abnormalities. Grading is not the same as staging. Staging has more to do with where the cancer is found in the body and how far it has spread.

Molecular Descriptions

In addition to the histopathology, other techniques may be used to assess the presence of cancer in the tissues, including fine needle aspiration cytology, and some of these techniques may be used more extensively in healthcare settings around the world.

Leukemias and lymphomas are diagnosed using a combination of their appearance:

  • Cytochemistry: enzymes that can enable certain chemical reactions to occur
  • Immunophenotype: markers or surface proteins that can be detected using antibody tests
  • Karyotype: chromosomal changes
  • Morphology: how the cells look

Other Sampling Techniques

Oftentimes in lymphomas and other cancers, a technique called immunohistochemistry is used to help assess the tumor type, prognosis, and treatment.

Immunohistochemistry involves using antibodies to stick to particular tags or markers on the outside of the cancer cells. These markers that the antibodies stick to often have "CD" in their name, which stands for cluster of differentiation.

For example, CD23 and CD5 are microscopic tags that, if present in the cancer cells, might support the notion that chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is a possible diagnosis.

These same markers are also present in other malignancies, however, so doctors use a sort of process of elimination based on the available information and what is known about the various malignancies and their "typical" CD markers.

Another example of a CD marker is CD20, which is present in some lymphomas but absent in others. Diffuse large B cell lymphoma, or DLBCL, is a very common lymphoma that is associated with the CD20 marker.

For a given sample of leukemia or lymphoma cells, markers can be tested using an entire panel of antibodies that stick to different markers, with positive and negative controls, built in.

Molecular and chromosomal studies may be done to look at gene rearrangements and specific changes to the chromosomes. Sometimes inserted or deleted genes are linked to information about prognosis.

For instance, in chronic lymphocytic leukemia, or CLL, a specific piece of a chromosome is lost, and often times lost along with it is a gene that helps suppress cancer.

The 17p deletion is found in about 5% to 10% of people with CLL, overall. The 17p deletion CLL is a form of CLL that is harder to treat with conventional chemotherapy.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Cancer Institute. NCI dictionary of cancer terms.

  2. Taxy JB, Husain AN, Montag AG. Biopsy Interpretation: The Frozen Section. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.

  3. Schafer KA, Eighmy J, Fikes JD, et al. Use of severity grades to characterize histopathologic changes. Toxicol Pathol. 2018;46(3):256-265. doi:10.1177/0192623318761348

  4. Pagani C, Coscia DR, Dellabianca C, Bonardi M, Alessi S, Calliada F. Ultrasound guided fine-needle aspiration cytology of breast lesions. J Ultrasound. 2011;14(4):182-7. doi10.1016/j.jus.2011.10.001

  5. Ho C, Rodig SJ. Immunohistochemical markers in lymphoid malignancies: Protein correlates of molecular alterations. Semin Diagn Pathol. 2015;32(5):381-91. doi:10.1053/j.semdp.2015.02.016

  6. Yu L, Kim HT, Kasar S, et al. Survival of Del17p CLL depends on genomic complexity and somatic mutation. Clin Cancer Res. 2017;23(3):735-745. doi:10.1158/1078-0432.CCR-16-0594

Additional Reading