Histopathology Report - How is it Done and What Does it Include?

Histopathology Report Techniques and Prognostic Predictors

What is histopathology and what information does it give?.

Definition: Histopathology

Histopathology is the examination of tissues from the body under a microscope to spot the signs and characteristics of disease. A histopathology report describes the tissue that has been sent for examination and the features of what blood cancer looks like under the microscope.  Occasionally a histopathology report is also called a biopsy report. 

Histology is the study of tissues and pathology is the study of disease; so histopathology, taken together, is literally the study of tissues as relates to disease.

Creating the Histopathology Report

The specialist doctor who does the examination under the microscope is called a pathologist. The tissue that is studied could be from a biopsy or a surgery. It is often removed from the diseased part of the body by a surgeon. 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. Frozen sections or slices are used sparingly in lymphoma due to problems in interpretation and sampling. In lymphomas, lymph nodes are the tissue most commonly examined in histopathology.

Components of the 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.

Estimating Prognosis and Further Defining Cancers

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.

Other Techniques

In addition to the histopathology, other techniques may be used to assess the presence of cancer in the tissues, including fine needle aspiration cytology. Often times in lymphomas and other cancers, something called immunohistochemistry is done to help assess the tumor type, prognosis and treatment.

For instance, the presence of the following markers may be investigated for lymphoma:
CLA (CD 45), L26 (CD20), CD 3, UCHL1 (CD45R0), kappa/lamda light chain restriction, CD 15, CD 30, bcl-2/bcvl-1, CD 5, CD 10, tdt.

For a given sample, markers can be tested using a whole panel of antibodies, 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 supress cancer.

The 17p deletion is found in about 3 to 10 percent of people with CLL, overall. 17p deletion CLL is a form of CLL that is harder to treat; people with 17p deletion CLL tend to be difficult to treat with conventional chemotherapy.

Also known as: biopsy report, pathology report, histopathy

Sources:

Ho C, Rodig SJ. Immunohistochemical markers in lymphoid malignancies: Protein correlates of molecular alterations. Seminars in Diagnostic Pathology. 2015. 32(5):381-91.

Histopathology Reporting: Guidelines for Surgical Cancer. By Derek C Allen. Springer Science & Business Media, Jun 29, 2013.

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