Histological examination is the morphological study of tissues and organs. It includes a biopsy and evaluation of material obtained during surgery.
This test is for diagnostic and therapeutic purposes. It is an important method for detecting cancer, as well as a way to determine the effectiveness of ongoing treatment.
To conduct a histological examination, they take the material and prepare it in a certain way for study. After that, careful microscopy is applied, as well as the qualitative and quantitative assessment of the obtained images.
The main object of analysis are histological preparations prepared from fixed structures. These include smears, prints, films of fabrics, as well as their thin sections.
For the manufacture of histological preparations, the necessary material is taken, fixed, compacted, sections are prepared, stained or contrasted. These stages go through preparations that are studied using electron microscopy. If a histological examination is carried out with a light orthoscope, then the obtainedsections must also be enclosed in a balm or other transparent medium.
To examine these preparations, various types of microscopes are used: light, transmission, scanning, electron, ultraviolet and luminescent, as well as phase contrast. The latter allow viewing contrast images of transparent objects that cannot be seen with conventional microscopy.
It is worth noting that when a histological examination is indicated, the material can be taken under visual control (in the case of a biopsy of the skin or visible mucous membranes), and also carried out by special methods (internal biopsy). So, tissues for research can be taken with a puncture needle, by aspiration, bone trepanation.
There is also the concept of targeted biopsy, when tissues for examination are taken under visual control using special optical devices or using ultrasound.
It is worth noting that in order for the histological examination to give true results, the material obtained should be immediately delivered to the laboratory. If this is not possible, the biopsy should be fixed with 10% formalin solution or 70% ethanol. If you need to conduct a pathomorphological study, then smears for cytology are required before fixing the material.
The pathologist who conducts the study first gives a macroscopic description of the material (indicates its size, color and consistency), and then applies the appropriate techniques to makehistological preparations. After that, he detects microscopic changes, conducts clinical and anatomical analysis and draws conclusions.
In what cases are histological examination methods used?
They are most commonly used to detect abnormal cells and confirm cancer. Thus, a histological examination of the cervix makes it possible to detect a malignant tumor process in almost 95% of cases.
Analysis of histological preparations is also used in the study of moles, gastric polyps, and various biomaterials. A histological examination of the fetus may also be used, which is prescribed for suspected hereditary pathologies.
