Pathology vs Histology: Differences and Similarities


Lab investigations are a crucial part of research and diagnosis. The gross and microscopic study of tissue helps understand the normal and the abnormal. Histology and pathology are two such branches of science that study any given structure under the microscope to help the examiner understand what is going on at a microscopic level.

human tissue image

 

So what is the difference between them?

Histology is the field of science where tissue is studied under the microscope to see the microscopic composition of that tissue. Pathology is the field of study where the disease process is studied. Pathology includes examining the tissues grossly (physical changes) and histologically. 

Histological study of any tissue enables the examiner to see the various layers of the tissue and the different types of cells forming the tissue. A histological examination is done to study the normal microscopic structure of the tissue and to see the changes that occur in the tissue during any disease process.

Pathology is a broader subject and includes studying the physical and histological changes in the tissue to understand the disease process. The study of microscopic changes in any pathology is known as histopathology. Pathologists also perform various other tests like immunohistochemistry and molecular tests like FISH (fluorescence in situ hybridization). These tests help them study the disease better, along with histological exams. 

What is Histology?

Histology involves the microscopic study of any organ or tissue. It can be done for research purposes or to study a disease process in a pathology lab. 

An example of a histological study is the biopsy— in which a tissue is taken out and sliced into thin sections. These thin sections are then placed on a slide for staining and visualized under the microscope. In the histological study of the biopsy sample, the different layers of the tissue with the pathological changes in them can be seen.

Histology can be done to study both the normal structures and the abnormal changes in the tissue.

Also, histology should not be confused with cytology, which is the study of cells. 

In cytology, cells are studied under a microscope after preparing a smear of the cells and staining them with appropriate stains. The examples of cytological study are:

  • FNAC (fine needle aspiration cytology), which is done for breast lumps and suspected thyroid cancers, and 
  • Pap smear– done to screen for cervical cancer. 

Only cells are visualized in this study, not the layers of the tissue. If there are any pathological changes in the cells, your doctor may proceed to the next test, i.e. biopsy. 

The histological study is more helpful in giving a confirmatory diagnosis. Cytology helps hint at pathology. 

The cytological study is, however, less invasive and is therefore sometimes done first to see if there is an abnormality present or not. On the other hand, a biopsy is more invasive as it requires a chunk of tissue that can be obtained in a clinic with or without local anesthesia or may need surgery to get the sample– depending on the condition.

You can follow the following youtube video to see the histological view of a few different types of cells in the human body:

 

What is Pathology?

Pathology is a branch of medicine that studies disease processes. It includes the study of how various diseases cause changes in a particular organ, tissue, or cells and what happens because of these changes. 

The biopsy is collected by the physician, surgeon, or pathologist and sent to the pathology lab for study. Slides are prepared using these samples for the assessment by the pathologist. A pathological study helps make a confirmatory diagnosis in many conditions.

A pathological examination will include the gross exam of any organ or tissue and the changes happening at a microscopic level. These changes may vary at different stages of the disease. 

After studying the microscopic changes, a pathologist comes to a diagnosis of the disease. The study will also help in staging the disease (wherever applicable).

Histology, cytology, and other advanced tests like molecular tests, etc, are a part of pathological exams as all of them help the pathologist understand the disease better.

Pathological studies are essential in hospital settings to make a diagnosis and in the research sector to understand the pathological processes of new diseases.

You can see the following video to understand what a histopathologist does:

 

Career as a Pathologist

A pathologist is a medical doctor that specializes in pathology. They play an essential role in making a diagnosis of various illnesses. Based on the pathological findings combined with the symptoms and other findings, a diagnosis is made. Your primary physician or surgeon then plans the treatment based on the combined information. 

To become a pathologist, you need to go through medical school to get your primary medical education and then pursue a residency/specialization in pathology.

Career as a Histotechnician

A histotechnician helps prepare the slides for the microscopic examination in a lab. They slice, fix, stain, and mount the specimen on a slide. The pathologist then examines this slide. 

A good slide preparation is the most crucial step in a histopathological examination. Therefore, a skilled histological technician is a vital part of any lab.

A histotechnologist also performs a similar role in a lab, but their training is more advanced when compared to that of a histology technician. They learn more about the background science involved in their work. Histotechnologists are more likely to get promoted to supervisor posts further in their career and may get the responsibility to oversee others’ work in the lab. 

A histotechnician can later do the certificate program to become a histotechnologist if they wish to learn more or if they desire to play more of a leadership role in the future.

It is a good option for those who don’t want to be a doctor or a nurse (i.e. those who don’t want to deal with the patients directly) but still want to be a part of medicine in some way.

There are separate certificate programs to become a histotechnician and a histotechnologist. The duration of the course varies, with the duration for the latter being longer and more advanced.

Career Opportunity in a Pathology Lab

The demand for a skilled pathologist and a skilled histotechnician is always there. Both of their skills determine an accurate diagnosis. With more and more research going on, pathologists and histotechnicians can work in a hospital, clinic, or research.

A skilled technician is a valuable addition to any lab as their skillful preparation of the slides is the first step to any diagnosis and the smooth functioning of the lab.

On the other hand, the skill of a pathologist determines accurate diagnosis in many conditions. They help physicians and surgeons see what is happening at a microscopic level in any disease. Based on their findings, the treatment is planned, and the prognosis is understood. They are essential for medical diagnosis in all the clinical branches of medicine.

With new research going on in the field of medicine– good pathologists and histotechnicians are required. They both play a crucial role in research and diagnosis.

Histology Vs Pathology: Points to Remember

So, what you need to remember is:

  • Histology is the microscopic study of a tissue, which enables the examiner to understand the normal microscopic composition and the abnormal microscopic changes in tissue.
  • Pathology is a broader field of medical science that focuses on studying the disease process and may use histological studies to understand the disease better.
  • Both of them are promising career options.

You can read about how to prepare a microscope slide mounting medium here: How To Make Microscope Slide Mounting Medium?

Dr. J

Dr. J has worked in biology all his life and holds several advanced degrees and certificates in biology, anatomy, scientific illustration, 3d animation and motion graphics. He has always had an interest in teaching others the wonders of biology using the latest advances in graphics, including visualization, digital microscopy, animation, illustration, VR and interactive media.

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