Introduction to pathology (I) What is pathology? What services can the Department of Pathology provide to you? From the medical point of view, pathology is a discipline that bridges basic medicine and clinical medicine by studying the etiology, pathogenesis, morphological and structural changes, and the resulting functional changes of diseases. However, for most non-medical professionals, “pathology” is an unfamiliar term. So what exactly does pathology do? What is the relationship between pathology and clinical medicine? What kind of tests does the pathology department in the hospital do? The close relationship between pathology and clinical medicine is evident in the study and diagnosis of diseases. In general, pathologists in hospitals are mainly engaged in surgical diagnostic pathology. Surgical pathology is a method of making a diagnosis by processing specimens obtained by local excision, clamping, puncture and scraping, removal and other surgical methods, and then by observing their morphology under the microscope. Pathological diagnosis is by far the most accurate diagnosis among all clinical and experimental techniques. It has been suggested that “pathological diagnosis is the gold standard”, and some even describe pathologists as “the judge who sentences people to death in hospitals”. This may be an overstatement, but it also illustrates the importance of pathological diagnosis. The “death penalty” mentioned here mainly refers to malignant tumors, which are extremely dangerous to human beings. But in fact, some malignant tumors can be treated better by radiotherapy and chemotherapy, and the pathological diagnosis provides the basis for the treatment plan of radiotherapy and chemotherapy. At present, the pathology department of our hospital has carried out the routine pathology diagnostic projects, such as clinical pathology diagnosis based on paraffin section and HE staining, clinical cytology diagnosis and intraoperative frozen section pathology diagnosis. We also carry out a number of projects such as kidney biopsy and special staining, immunofluorescence and immunohistochemistry. Among them, immunohistochemical examination includes the detection of junctional lesions (precancerous lesions) and prognostic indicators of malignant tumors based on immunohistochemical techniques, the determination of certain oncogene expression proteins, the determination of certain receptors and the determination of cell proliferation activity, as well as tumor differential diagnosis related items based on immunohistochemical techniques, etc. Clinical cytology diagnosis includes sputum, fiberoptic bronchoscopy, pleural fluid, ascites, urine and cervical scraping and aspiration cytology for cancer cells.