What are the conditions that require pathologic examination? Clinicians judge whether a patient needs pathological examination and choose the way to obtain tissue specimens, such as surgical excision, needle core puncture, scratching, clamping, etc., according to the specific condition of each patient during diagnostic and therapeutic activities. Usually, the purpose of pathological examination is to make a clear diagnosis, which is used to determine whether the nature of the lesion is inflammation or tumor, and if it is a tumor, whether it is a benign or malignant tumor, and so on. For patients who need to undergo pathology examination, the pathology report is the medical “judgment” of the nature of the patient’s lesion. What is the significance of pathology examination? Pathological diagnosis is directly related to the clinician’s choice of treatment plan and the prognosis of the disease. In the multidisciplinary clinical pathology seminar, the pathologist usually makes a final decision at the end of the consultation and discussion to announce the pathological diagnosis and unveil the mystery of the disease manifestation, thus, the medical profession believes that “the last word is to be said by the pathologist”, and the pathological diagnosis is also known as “final diagnosis”. Pathologic diagnosis is also known as “final diagnosis”, and the pathologist is called “the doctor’s doctor”. For example, in a patient with enlarged lymph nodes, the lymph nodes are removed and a pathologic examination is performed. If the pathological diagnosis is “chronic lymphadenitis”, the clinician can take internal medicine treatment; if the pathological diagnosis is “Hodgkin’s lymphoma”, it is necessary to carry out chemotherapy immediately; if the pathological diagnosis is “metastatic adenocarcinoma”, it is necessary to take systemic systemic treatment. If the pathological diagnosis is “Hodgkin’s lymphoma”, chemotherapy should be carried out immediately; if the pathological diagnosis is “metastatic adenocarcinoma”, systematic examination of the whole body is needed to search for the primary lesion, and surgical resection should be carried out if possible. Why can’t the pathologic examination be “immediate”? The conventional pathology technique is paraffin embedded section. The specimen is made into thin slices 3 to 5 microns thick, stained with hematoxylin and eosin (HE) to make pathological sections. During this period, more than 40 technical steps are required, taking more than ten hours. Improper handling of any part of the process will affect the clarity of the section, leading to unclear observation of the morphology of the cells by the pathologist, and affecting the accuracy of the pathological diagnostic results. In addition to the time constraints of the slice production cycle, the diagnostic process of the pathologist under the microscope is completely dependent on the pathologist’s professional experience, which cannot be replaced by any machine and also requires time. Therefore, the pathology examination is different from the ordinary blood test program, and can not be achieved “immediately”. The corresponding regulations made by the Ministry of Health is to require the Department of Pathology to generally receive the specimen within 3 to 5 working days after the report, delayed as appropriate in difficult cases. In addition to routine paraffin sections, pathology techniques also include immunohistochemistry and in situ hybridization, which take 1 to 2 working days. Why are intraoperative frozen sections required for certain procedures? Why are paraffin sections done afterwards? Intraoperative frozen section can be performed to obtain diagnostic pathology results within 20 to 40 minutes. As the name suggests, “intraoperative” means during the operation; “frozen section” means that the excised tissue is placed in a frozen sectioning machine at about -20℃ to rapidly freeze and harden the tissue for sectioning. Intraoperative frozen section examination is mainly used for patients who cannot be clearly diagnosed before surgery. The usual surgical plan for these patients is a “two-step” approach: the first step is to locally excise the mass as part of the surgical scope of a benign lesion; the second step is to decide whether the patient needs a second, more extensive surgery based on the results of a routine pathology report. There is a waiting period of several days between the two steps, and the patient not only suffers financially, but also mentally. Intraoperative frozen section examination can determine the benign or malignant nature of the lesion during the operation, providing a guiding reference for the surgeon to decide the scope of the operation, thus turning the “two steps” into “one step”. However, intraoperative rapid biopsy also has the scope of caution and inappropriate application. Compared with conventional paraffin sections, it has a simplified tissue processing procedure, the cellular morphology is not clear enough, artificial artifacts in the sectioning process may occur, and generally only a preliminary judgment of the nature of the lesion can be made, or sometimes not even a preliminary judgment can be made. Therefore, after the intraoperative rapid section examination, the remaining tissues should also be examined by conventional paraffin section, and the final pathological diagnosis is based on the diagnosis of conventional paraffin section. Of course, in general, the consistency of the results of these two methods is more than 95%. How to read the pathology report initially? Generally speaking, there are 4 basic types of pathology report presentation. Category 1 is a positive diagnosis: the nature of the lesion diagnosis is clear, directly give a positive pathological diagnosis. Category 2 is not completely sure of the diagnosis: according to the different degrees of intent, in the proposed diagnosis before the name of the lesion is crowned with such as “consider as”, “in line with”, “tend to”, “suggestive”, “possible”, “suspected”, “cannot be excluded (except)”. means that the diagnostic opinion of the pathology is reserved. Category 3 is the diagnosis of insufficient basis for the lesion: it means that the lesion shown in the section is insufficient to make the diagnosis of category 1 or 2 above, and only the morphological points of the lesion can be described in the report, i.e., the descriptive report without diagnostic opinion. Category 4 is unable to make a diagnosis: the pathology report states that the specimen cannot be diagnosed and the reasons why it cannot be diagnosed, such as the specimen sent for examination is autolysed, dried up, too small, severely deformed by extrusion, denatured by cauterization, or unable to be made into a slice for some reason, and so on. Any type of pathology report should not be separated from the clinic, especially for category 2 and 3 diagnostic reports, clinicians need to combine multiple aspects of the examination data to choose the appropriate treatment plan. In addition, the pathologist can only observe the specimen submitted for examination. When the results of the pathology report differ greatly from the clinical manifestations, it may be due to the fact that the tissues submitted for examination are not representative of the disease, and the clinician may consider performing multiple biopsies according to the needs.