I. The Concept of Pathological Examination

Pathological examination involves obtaining tissue specimens or cell specimens through surgical operations or punctures, and then preparing them into tissue sections (pathological glass slides made from organs or tissues) or cell smears (pathological glass slides made from cell specimens) in accordance with strict procedures. Under the microscope, by observing the abnormalities in cell morphology and tissue structure, and comprehensively analyzing the patient's clinical symptoms and other examination data, a pathological diagnosis report that conforms to the patient's condition is provided.

For instance, the appendiceal tissue removed by a surgeon must be sent to the pathology department for pathological examination to determine whether it is a tumor or an inflammation. If it is a tumor, what type of tumor is it? If it's inflammation, what kind of inflammation is it? You might think, if it's just appendicitis, why would you spend money on a pathological examination? In fact, this is not the case. You may think that appendicitis is merely a symptom of appendiceal tumor. However, in clinical practice, the clinical manifestations of many tumors are not typical. Therefore, in clinical practice, relying solely on clinical manifestations and the surgeon's visual judgment of the nature of the lesion can lead to misdiagnosis. Only pathological examination can more accurately determine the true condition of the lesion. So, the shallowness of a pathological examination must not be compromised!

Ii. Situations where pathological examination is required

1. When CT or B-ultrasound detects any space-occupying lesion in the patient's body, it is necessary to clarify the nature of the mass. For superficial skin, breasts, lungs, liver, gastrointestinal tract, bladder and other organs throughout the body, biopsy tissues or cells should be taken through puncture or endoscopy (such as bronchoscopy, gastroscopy, cystoscopy, etc.) for pathological examination.

2. Any tissue removed through surgery, tissue or cells obtained by puncture, pleural and peritoneal effusion from puncture, pericardial effusion, puncture fluid, etc., must be sent for pathological examination.

3. Lumps that recur after surgery.

4. If a tumor has been previously diagnosed as malignant and a new space-occupying lesion is found in another area or enlarged lymph nodes are discovered, a pathological examination can be conducted after puncture or surgery.

5. For patients with advanced tumors, especially those who cannot undergo surgery and can only receive chemotherapy, radiotherapy, targeted therapy and immunotherapy, a pathological examination report must be available as a basis before corresponding treatments can be carried out.

Therefore, the pathological examination report is also known as the "gold standard" for disease diagnosis. Although this "gold standard" is not entirely accurate, it at least has more objective value compared to the speculative diagnosis of diseases through tests, B-ultrasound, radiology and other examinations.

Iii. Pathological Diagnosis: Not Only about tumors

Pathological diagnosis can not only diagnose tumors but also non-tumor lesions, including infectious diseases and non-infectious, non-tumor diseases (such as autoimmune diseases and connective tissue diseases).

1. Tumor diagnosis

Pathological diagnosis is the main method for tumor diagnosis.

2. Examination and diagnosis of inflammation

Whether it is a general inflammation or a special type of inflammation, a mass often forms during or in the later stage of its development. For instance, pulmonary tuberculosis can form a tuberculous bulb, while other lesions can create a protrusion that protrudes from the surface of normal tissue. Clinically, doctors cannot determine with the naked eye what this mass or protrusion is. Generally, surgical removal is required for pathological examination to determine whether it is a tumor-like or non-tumor-like mass.

Inflammation includes common inflammation and special types of inflammation. Common inflammation refers to general bacterial lesions. Special types of inflammation include tuberculosis, an inflammatory lesion caused by Mycobacterium tuberculosis, which can infect many parts of the human body, such as pulmonary tuberculosis, lymph node tuberculosis, renal tuberculosis, etc. Syphilis, an inflammatory lesion caused by Treponema pallidum infection, is a disease mainly transmitted through sexual contact and mother-to-child transmission. ③ Viruses, such as AIDS, are inflammatory lesions caused by HIV infection, mainly transmitted through sexual contact and mother-to-child transmission. ④ Lesions caused by infections such as roundworms, pinworms, and Plasmodium.

3. Diagnosis of lumps caused by foreign objects such as sutures, drugs and other substances that cannot be absorbed by the human body

For instance, in the case of intramuscular injection in the buttocks, due to individual differences, the drug may not be fully absorbed. The unabsorbed drug, as a foreign body, will stimulate the normal tissues around it to proliferate, thus forming a mass in the buttocks. At this point, surgical removal is required for pathological examination to diagnose whether the mass is neoplastic or foreign body.

4. Diagnosis of masses formed due to trauma, bleeding, fractures and other reasons

Sometimes, trauma or fractures may merely be triggers. In the tissues that have undergone degeneration and necrosis due to trauma or fractures and have been surgically removed, there may be tumor cells. Especially in pathological fractures (when the bone itself is diseased, a tumor grows, or a tumor from another place has metastasized to the bone, fractures may occur. This is because bone tumors sometimes have no symptoms. This is even more so when bone lesions are only discovered after a fracture.

In clinical practice, it is often the case that doctors or patients, thinking that fractures are not serious, discard the surgically removed parts. It is not until the surgical incision has not healed for a long time that they undergo another operation to take tissues for pathological examination, only to find out that the fracture is caused by a malignant tumor. For skin wounds that have not healed for a long time or skin that has been infected, burned or ulcerated, due to long-term inflammatory stimulation, the skin may develop cancer. It is essential to conduct surgical sampling and pathological examination. Everyone must pay close attention to this situation.

5. Early cancer screening

The pathology department also issues pathological reports on early cancer screening for some organs: Currently, the best solution for tumors in the medical field is early prevention, early detection, and early treatment. Therefore, early cancer screening is an indispensable means in tumor prevention and treatment.

The early cancer screenings that the pathology department participates in are more frequently and effectively for cervical cancer and early gastrointestinal cancer. In particular, cervical cancer screening was carried out relatively early and on a large scale. Cervical cancer screening has been included in the Healthy China strategy project.

Why does the state invest so much money in cervical cancer screening? Cervical cancer is a type of cancer with a clear cause (most cervical cancers are caused by HPV infection), and early detection and treatment of cervical cancer not only lead to a cure but also cause less trauma, lower medical expenses, and enable patients to enjoy a high-quality life. In the advanced stage, not only is the trauma significant, but the treatment effect is also unsatisfactory, the prognosis is poor, the medical expenses are extremely high, and the patient's quality of life is also very poor.

The screening for cervical cancer mainly involves gynecological TCT (also known as gynecological liquid-based cytopathological examination) or cervical smear (a commonly used screening method before the advent of TCT technology, which is now rarely used in outpatient clinics for cervical cancer screening or diagnosis, and may only be used in large-scale screening), along with cervical HPV testing.

The screening for early esophageal and gastrointestinal cancer mainly involves conducting gastroscopy and colonoscopy for high-risk groups, taking tissues from random or suspected lesions and sending them to the pathology department for HP (for details, see the early gastrointestinal cancer screening later) testing, as well as pathological diagnosis of precancerous lesions and early cancer.

Therefore, the pathology department has both pathological diagnosis reports for tumors and those for non-tumors.

Ⅳ. A Good Pair: Surgery and Pathology

1. Pathology and surgery are interdependent and mutually reinforcing

Why is pathology also known as "surgical pathology"? The name itself indicates that the relationship between surgery and pathology is closely related. It can be said that without specimens removed through surgical operations, there would be no pathological examination, and thus no pathology department. However, without the pathology department, surgery cannot make significant progress either. The precise diagnosis of the pathology department can not only accumulate diagnostic experience for surgeons but also assess the effect of surgical resection (the pathology department can provide pathological examination diagnosis reports such as whether the surgical margin is clean and whether there is lymph node metastasis after surgery for the surgery department). At the same time, it also provides reliable basis and guarantee for the postoperative treatment of patients with malignant tumors. Pathology has played an irreplaceable role in the development of surgery. Pathology and surgery have a complementary relationship: you are in me and I am in you, and neither can do without the other.

2.Pathological examination is so important for surgical diagnosis and treatment

(1) Diagnostic accuracy: Pathological examination involves observing the appearance of surgically removed specimens, then preparing them into pathological sections or smears. Pathologists carefully observe and study the cells in the smears under a microscope and comprehensively analyze the patient's clinical and other examination data to determine the nature of the lesion, the type of tumor, the degree of the lesion, and whether there is a malignant lesion, etc. In surgical operations, pathological examination can provide accurate and reliable diagnostic basis.

(2) Staging diseases: Pathological examination not only helps doctors determine the nature of the lesion but also stages malignant tumors. By conducting pathological examinations on the surgically removed specimens, doctors can understand the development stage of malignant tumors, whether there is metastasis, the involvement of surrounding tissues, etc., thereby accurately staging the disease for patients, which is helpful for doctors to formulate more reasonable treatment plans and assess the prognosis of patients.

(3) Treatment plan formulation: The results of pathological examination have significant guiding significance for doctors to formulate treatment plans. For instance, for patients with malignant tumors, pathological examination can assist doctors in determining the type and malignancy of the tumor, thereby formulating more personalized treatment plans, such as chemotherapy, targeted therapy, and immunotherapy. In addition, for some masses formed by benign diseases, such as those suspected to be caused by tuberculosis, syphilis, parasites, etc. through pathological examination, further specific laboratory tests can be conducted in clinical practice for diagnosis. Corresponding specific treatments should be provided to the patients to avoid misdiagnosis and mistreatment.

(4) Prognosis assessment: Through pathological reports, surgeons can understand the development of the patient's lesion, the degree of malignancy, and whether there is metastasis, etc. At the same time, they can also obtain objective evidence for targeted medication or immunotherapy, thereby conducting an accurate prognosis assessment of the patient, which is helpful for doctors to formulate more reasonable diagnosis and treatment plans and rehabilitation plans.

(5) Scientific research value: Through pathological examination, doctors can conduct in-depth research on the nature and development patterns of lesions, providing valuable experimental data and theoretical basis for the study of medical diseases. Pathological examination can also identify the cause of unexplained deaths (such as autopsy), providing objective research data for disease studies. Pathological examination can also be used to study specimens, which can explore the occurrence and development of diseases, such as discovering gene mutations in malignant tumors, thereby providing objective research data for the development of new anti-tumor targeted drugs.

(6) Enhance medical quality and promote the development of surgery: Through pathological examination, doctors can diagnose diseases more accurately, formulate treatment plans and assess prognosis, thereby improving medical quality. Meanwhile, pathological examination can also help doctors identify their own shortcomings in the diagnosis and treatment process, promoting their continuous learning and improvement of their diagnosis and treatment skills.

(7) Patient rights Protection: Pathological examination is one of the important means to safeguard patients' rights and interests. By conducting pathological examinations on the specimens removed through surgical operations, unnecessary pain and losses to patients caused by misdiagnosis and mistreatment can be avoided. Meanwhile, the results of pathological examinations can also help doctors better understand the patient's condition and formulate more personalized treatment plans, thereby better safeguarding the patient's rights and interests.

(8) Significance in medical education: Pathological examination is also of great significance to medical education. By conducting pathological examinations on the specimens removed through surgery, medical students can better understand the nature and development patterns of the lesions, and deepen their knowledge and understanding of the diseases. Meanwhile, pathological examination can also help medical students cultivate correct clinical thinking patterns and improve their own medical literacy.

From the above introduction, everyone may have understood that the pathology department is a department that explores the occurrence and development of diseases, diagnoses diseases, guides clinical treatment, and judges the prognosis of tumors.

According to relevant national laws and regulations, tissues and organs taken from the human body for judgment and treatment purposes should be promptly and completely sent to the pathology department for examination in accordance with the specific requirements of the pathological examination items. Not only the specimens removed by surgical operations must undergo pathological examination, but also the puncture biopsies of minimally invasive surgeries, such as coarse needle puncture of lymph nodes, puncture of tissues like the prostate, breast, liver, and kidneys, fine needle puncture of cells from the thyroid or lymph nodes, and other superficial and deep organs, must undergo pathological examination to confirm the nature of the lesion and determine an accurate clinical diagnosis.

It can be said that the surgical resection specimens are sent to the pathology department for pathological diagnosis and to obtain the pathological report. Pathological diagnosis also guides surgical treatment activities, so pathologists are called "doctors among doctors" abroad.

The development of surgery has promoted the development of pathology, and the development of pathology has also promoted the development of surgery. Because pathologists are the other pair of eyes for surgeons to diagnose diseases. Without the pathology clinic of pathologists, surgeons are like blind people walking in the diagnosis of surgical diseases, only able to cross the river by feeling for the stones. Although they can walk, it is difficult and they cannot go far.

Let's return to the patient's question: "There's a tumor. Why send it to the pathology department? Just cut it off and it's done." " It's just appendicitis. Do they still need to be sent for a pathological examination? What a hassle." Even some overly "confident" clinicians may have the same question.

But the truth is far from what you think: for instance, when a doctor feels that a patient's superficial lymph nodes are swollen, does it mean that there are many causes of swelling, such as inflammation (including tuberculosis), metastasis of malignant tumors, lymphoma, etc. Some of them present with symptoms of appendicitis, but pathological examination reveals appendiceal cancer! This situation occurs from time to time in clinical practice, not by chance but in a certain number.

Therefore, it is essential to remember that whether it is cells or tissues obtained through any surgical operation or minimally invasive endoscopy, such as puncture examination of the prostate, breast, kidney, liver, etc., or body fluids such as pleural effusion and ascites obtained by doctors through puncture or drainage, they must all be sent for pathological examination.