Introduction to Pathology vol.1


This is Naoko from in recruitment / public relations team at Medmain.

In this blog “Medmain Speaks”, you can find interviews with our members, company news and so on but we also would like to write a series of articles about pathology, as it is the most related area of our service.

The terms such as “Pathology” “Pathologist” may not be well known generally.

Today, I would like to introduce you some types of “pathology”.

I hope this post will be an opportunity for more people to get to know or deepen understanding of the importance of “pathology”, which plays a very important role in the medical field.

▼So again, what is “pathology”?

Medmain provides a “pathological image analysis system” using Deep Learning, but many of you may not be familiar with the word “pathology”.

(Before I joined Medmain, I was only aware of its existence after stumbling upon a Japanese comic featuring a pathologist called “Frazile.”)

I mentioned this a bit in my first post on this blog, “We started company blog, but what is “pathology” in the first place?

When we go to the hospital, the doctors who we usually see are called “clinicians”, but there are many cases when the precise cause of the disease needs to be identified by a specialist called a “pathologist”.

For example, when it is necessary to determine whether a patient’s tumor is benign or malignant, the lesion’s tissue and cells taken from the patient’s body will be used to make a prepalate for the microscope.

The preparate is then examined under a microscope and a diagnosis is made. Such a diagnosis is called “pathological diagnosis”.

A diagnosis by a pathologist is a “definitive diagnosis,” and treatment is performed according to this diagnosis, so the diagnosis is extremely important.

▼Types of pathological diagnosis

There are various types of “pathology” depending on every scene.

Let’s take a look at each of them.

❶Cellular diagnosis (cytology)

In“Cytology”, they diagnoses the presence of “cancer cells”,for example that have peeled off in liquid components such as phlegm and urine.

In a screening for uterine cancer, cells are rubbed directly from the cervix instead of liquid itself, and in a breast cancer screening, if there is a lump in the breast, it is diagnosed by pricking it with a needle and aspirating the cells.

❷Historogical diagnosis (biopsy)

For example, when endoscopy of the stomach, colon or lungs is performed, a portion of the lesion is pinched and then examined.

The lesions are harvested with tiny scissors or by sticking a needle through the endoscope.

Unlike cytology, it takes a mass of tissue and cells in the body and diagnoses whether or not there is cancer there.

After the cancer is confirmed, treatment schedule will be decided and for example the stomach / colon will be surgically removed. Then the tissues and organs will be examined again by histological examination. This leads to confirmation of the extent of the surgery and decisions about additional treatments. (Of course they also diagnose diseases other than “cancer” and determine the effect of treatment.)

❸Diagnosis of the organs and tissues removed by surgery

The pathologist observes removed organs and tissues through a microscope and check the site, size, character and spread of the lesion, and then cut out the necessary number of parts for diagnosis. A clinical lab technician makes a microscopic specimen of the organ and tissue, and a pathologist observes the specimen through the microscope to determine if all the bad parts have been completely removed or additional surgery is needed, and if there is any other spread or not.This will be used for subsequent treatment.

❹Rapid diagnosis during surgery (rapid intraoperative diagnosis)

In cases that biopsy tissue diagnosis can not be made before surgery or that biopsy is difficult due to deep lesions, tissue is taken and examined during surgery.

When they are trying remove a lesion, they want to make sure that they are getting the enough extent of the lesion,and also to make sure there is no lesion at the end of the incision. This situations happen a lot in actual surgery.

During the surgery, the surgeon must stops and waits as he or she cannot proceed to the next step until he gets the results. When a request for a rapid intraoperative diagnosis is received, a frozen specimen is prepared from the specimen that was collected in the surgery, a pathological diagnosis is made, and the results will be promptly given to the physician who is performing the surgery.

In this way, it helps to determine whether the extent of resection of the tumor is sufficient and whether the tumor is benign or malignant.


With the consent of the bereaved family, human autopsies are performed for the purpose of validating clinical diagnosis, determining the effect of treatment, directly elucidating the cause of death, and discovering secondary complications and incidental lesions. A pathologist perform this as well.

▼As “Doctor’s doctor”

When we go to the hospital, we rarely see pathologists, so we don’t have a chance to know what they do. However, they are the “power behind the scenes”.

In some countries, they are called “Doctor’s doctor”.

In the absence of a pathologist, there may be cases where the surgery cannot be performed due to the inability to make a prompt diagnosis, and above all, the patient cannot receive appropriate treatment without pathological diagnosis.

One of their work, such as “pathological dissection”, is also essential for the advancement of better quality medical care in the future.

As you can see, pathological diagnosis is used in a variety of cases and is extremely important in medical field.


In this blog “Medmain Speaks”, we will continue to bring you information about pathology, as well as “Focus on the Medmainer”, interviews with Medmain members.

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