What Is Pathology
Modern medicine relies on the combined medical and scientific skills of the pathology laboratory to assist in the investigation and management of a patient's illness.
At the heart of pathology is the care of the patient. The pathology laboratory must produce accurate and reliable results quickly in response to their colleagues' requests. The modern pathology laboratory is a complex operation that relies on the skills and teamwork of many people to ensure that each patient and doctor receives the best service possible.
The pathologists, with their blend of general medical training and specialist training in the science and discipline of pathology, supervise the laboratory investigations as well as consulting with the patient's doctor. The modern pathology laboratory also requires the skills of highly trained professional scientists and technicians, as well as various equally skilled support staff to ensure that investigations are performed efficiently and accurately.
Any pathology investigation starts with one or more specimens obtained from the patient. Doctors may collect some specimens, while special collection staff or the laboratory can collect others. Pathology laboratories examine a wide range of specimens including blood, urine and tissue specimens.
Once the specimen has arrived in the laboratory, depending on the tests requested, various expert departments may be involved in the investigation. Some tests are simple and can be performed rapidly, though more complex tests can take days. Some tests can only be performed by highly specialised laboratories and the specimens may need to be sent interstate or even internationally to the appropriate laboratory.
Once the tests are completed and checked for accuracy, a report is sent to the patient's doctor.
Chemical Pathology
Chemical Pathology is the diagnosis and monitoring of disease through the measurement of changes in the chemical composition of blood, urine and other body fluids. Tests are used to monitor kidney and liver function, to diagnose endocrine diseases such as diabetes and infertility, to assess nutritional status and measure drug levels in blood and urine. This is the most automated area of a modern diagnostic laboratory and there is a great deal of emphasis on the accuracy and precision of the results that are produced.
Haematology
Haematology is the study of the morphology of blood cells, the physiology of the blood and the blood forming organs. This encompasses the use of automated instruments to count blood cells and haemoglobin levels. Blood smears are used to examine the cell types and appearance of the blood cells to diagnose haematological diseases and to monitor the progression of treatment. Bone marrow examinations by aspiration biopsy aids in the diagnosis of these diseases. Another area of importance is the study of blood coagulation, measuring the ability of blood to clot, either to check before surgery, or investigating patients who have unexplained bleeding or clotting, or monitoring patients on anticoagulants. Transfusion medicine is another arm of haematology dealing with blood groups, antibodies and blood transfusion.
Microbiology
Microbiology is the study of microscopic organisms including viruses, bacteria, fungi, algae, worms and protozoa. Microbiology is concerned with their distribution, their role in the environment and their relationship to humans, in health and disease. Any body fluid or tissue can be examined for organisms or evidence of infectious disease. The role of the microbiology laboratory are the isolation and reliable identification of infectious organisms, and testing to identify the most appropriate treatment to fight the infection.
Infectious disease serology is also performed in the medical microbiology laboratory. These tests use the presence of antibodies or DNA from the organism in the blood, to help diagnose infectious diseases.
The role of the Medical Microbiologist is to provide interpretation of the results and advise referring doctors on the initial management of patients. Medical Microbiologists also play a leading role in Infection Control, and work with the scientists to maintain relevant and up-to-date tests.
Cytopathology
Cytopathology is a specialist discipline that includes diagnostic and screening components. Diagnostic cytology uses non-invasive and minimally invasive techniques to collect cellular material to confirm or exclude malignancy. Specimens examined include sputum, urine, brushings and washings from various organ systems and fine needle aspirates of palpable or radiologically identified lesions. The National Cervical Cancer Screening Program relies upon the Pap smear to identify asymptomatic women with premalignant disease. The interpretation of cervical smears is a non-automated discipline, which has an extensive and varied quality control system in place to monitor and improve standards.
Histopathology
Histopathology is the branch of pathology that deals with the tissue diagnosis of disease. The tissue on which the diagnosis is made is biopsy material taken from a patient to detect and diagnose disease, examine disease progression including the response to treatment or lack of response, and to establish the cause in cases of sudden or unexpected death. A large part of this is the detection and diagnosis of cancer. A tissue diagnosis is essential before commencing treatment involving major surgery, radiation or drugs, treatments which may have major side-effects