Histopathological examination consists in microscopic evaluation of a tissue section. This may be, for example, a histopathological examination after curettage to find out the cause of fetal death, or a histopathological examination of the stomach after gastroscopy. However, the histopathological examination is of particular importance in the diagnosis of neoplastic diseases. What is the histopathological examination? How to interpret its results? What is the waiting time for the results? Is the histopathological examination reliable?

Histopathological examinationis a laboratory examination aimed at assessing the type and degree of the disease process in the collected tissue. Histopathological examination has an advantage over cytological examination as it enables spatial evaluation of pathological changes in the tissue. Histopathological examination is invasive as it requires the collection of biological material from the tissue.

Histopathological examination - indications for the examination

  • suspected cancer, e.g. melanoma, ovarian cancer, lymphoma
  • suspected bacterial infection, e.g. Helicobacter pylorii
  • suspected autoimmune disease, e.g. celiac disease, psoriasis
  • inflammatory bowel diseases, e.g. Crohn's disease
  • histopathological examination of the fetus after miscarriage

Histopathological examination - material for examination

Biological material for histopathological examination is collected

  • in operation
  • during the post-mortem examination
  • by biopsy

A biopsy is an invasive procedure that involves the removal of a fragment of diseased tissue, usually with a margin of unchanged tissue.

A biopsy can be taken from organs such as the thyroid gland, liver, mammary gland, lymph node, and ovary. There are several types of biopsy, incl. fine needle aspiration biopsy (BAC), fine needle aspiration biopsy (FNAB), core biopsy, excision biopsy, biopsy biopsy, drill biopsy, scratch and scrap biopsy.

Histopathological examination - what is it?

The collected tissue fragment is immediately placed in a fixative, e.g. formalin, during the biopsy. This is to stabilize the sample and prevent it from deterioratingbiological. The sample is then dehydrated in concentrated ethanol in the laboratory. Finally, the fragment is poured with paraffin and, after hardening, it can be cut into several-micrometer sections using a special cutting device (microtome).

The next step is to observe the tissue scraps on the slide under a light microscope. To facilitate the evaluation of the section, it can be treated with an appropriate staining, which depends on the type of tissue being examined and what the viewer wants to obtain.

After staining, the individual components of cells or tissues are easier to distinguish. Staining can also highlight pathological structures that should not be found in normal tissue.

Despite the displacement of traditional diagnostic methods by more and more advanced laboratory techniques, histopathological examination is still an essential element of the diagnostic process of many diseases.

Basic staining is hematoxylin, which stains the cell nucleus blue, and eosin, which stains the cytoplasm red. Staining with mucicarmine or alcyan blue reveals the mucus, which allows for a detailed diagnosis of neoplasms.

Immunohistochemical stains are used to detect specific proteins (antigens), e.g. receptors, fragments of cell structures in a tissue using monoclonal antibodies linked to an enzyme. Then adding a substrate for the enzyme reveals the desired structures.

For the labeling of antibodies, fluorochromes, e.g. fluorescein, are also used instead of enzymes. This method is then called immunofluorescent staining. These types of staining are important in determining the type or degree of differentiation of the neoplasm.

It is extremely important in prognosing and choosing a therapy. By examining the expression of certain receptors, it is known whether the tumor will respond to the selected drug targeting these receptors.

  • Histopathological examination after miscarriage [Expert advice]
  • Pregnancy died in 10 weeks - histopathological examination after curettage [Expert's advice]
  • Histopathological examination and cervical dysplasia [Expert's advice]
Worth knowing

Histopathological examination - price, waiting time for results

The prices of the histopathological examination range from 40 to even 400 PLN. The waiting time for the results is up to several weeks.

Histopathological examination - results and their interpretation

The person who interprets and authorizes the results of the histopathological examination is a specialist in pathomorphology (pathomorphologist). Interpreting the resultdepends on the tissue taken. The disease process causes the tissue to undergo:

  • hypertrophy (hypertrophy), i.e. enlargement resulting from the enlargement of individual cells, without increasing their number in the tissue
  • growth (hyperplasia), i.e. enlargement due to an increase in the number of cells and not always due to the cancer process
  • atrophy, i.e. decrease in the volume of cells, and consequently the tissue or organ
  • metaplasia, i.e. the appearance of cells with altered morphology and functions in response to an irritating factor, e.g. a microorganism
  • dysplasia, i.e. abnormalities in the appearance of cells and a disorder of the tissue structure indicating a process leading to neoplastic transformation

The test also allows the assessment of the tumor grade (G) and its clinical stage using the TNM classification for solid tumors. In the latter classification, the abbreviations used for evaluation are: T (tumor), N (nodus), M (metastases).

Similar classifications have also been created for non-cancerous diseases. An example is celiac disease where he uses the Marsh classification.

References

  1. Clinical pathomorphology. edited by Kruś S. and Skrzypek-Fakhoury E. PZWL Publishing House Warsaw 2007, issue 3
  2. Brierley, J.D. et al. TNM classification of malignant tumors. Chichester, West Sussex, UK 2022, Wiley-Blackwell Issue 8
About the authorKarolina Karabin, MD, PhD, molecular biologist, laboratory diagnostician, Cambridge Diagnostics Polska A biologist by profession, specializing in microbiology, and a laboratory diagnostician with over 10 years of experience in laboratory work. A graduate of the College of Molecular Medicine and a member of the Polish Society of Human Genetics. Head of research grants at the Laboratory of Molecular Diagnostics at the Department of Hematology, Oncology and Internal Diseases of the Medical University of Warsaw. She defended the title of doctor of medical sciences in the field of medical biology at the 1st Faculty of Medicine of the Medical University of Warsaw. Author of many scientific and popular science works in the field of laboratory diagnostics, molecular biology and nutrition. On a daily basis, as a specialist in the field of laboratory diagnostics, he runs the content department at Cambridge Diagnostics Polska and cooperates with a team of nutritionists at the CD Dietary Clinic. He shares his practical knowledge on diagnostics and diet therapy of diseases with specialists at conferences, training sessions, and in magazines and websites. Particularly interested in the influence of modern lifestyle on processesmolecular in the body.

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