The Pathology Department accurately diagnoses and classifies human diseases through morphological, immunological, and molecular biological tests and determination, which is an important role for treating patients, and various pathological research and training are conducted in relation to human diseases. In addition, accurate diagnosis and direction of proper treatment are suggested to patients through regular multidisciplinary treatment with each clinical department in the site and collaborative treatment system.

The classification of tumors has become complicated as medicine has developed with disease names changing and new disease names being created. The clinician uses various tests to approach the patient's disease by making accurate diagnosis through histopathology tests, cytopathology tests, immunopathology tests, molecular pathology tests, micropathology (electron microscope) tests, and autopsy pathology. Accurate diagnosis is the start of treatment, and pathological diagnosis is a significant method to give definite diagnosis for diseases.

While pathological diagnosis depended on morphological opinions in the past, the present pathological diagnosis is changing into comprehensive diagnosis for the classification and prediction of prognosis of patients according to the biological, immunological, and molecular genetic characteristics of diseases instead of simply diagnosing disease names. Various clinical treatments have recently been developed following this change, and the era of treatments customized to the characteristics of diseases is opening as they are applied to patients.