ANATOMICAL PATHOLOGY LABORATORY: HOW FAR DO YOU KNOW IT?

In daily medical practice, people are very accustomed to hear about laboratory examinations as one of the diagnostic tests. But not many people know that kinds of laboratory which are often abbreviated as lab are vary. Most people assumed the lab examinations are only related to blood, urine or feces. Actually, there is a kind of lab that specifically examines body fluids or tissues to assess the morphological changes of body cellsto identify the presence of tumors or cancer, inflammation, infection, and others. The laboratory was named as the Anatomical Pathology Laboratory, more popular abbreviated as pathology lab.

        The pathology lab is led by a pathologist (in Indonesia named Sp.PA). In this lab, besides the pathologist, there must be histotechnician and cytotechnician. The specimen that received by the lab must be examined macroscopically and sampled by pathologist. The selected sample is then processed by the histo/cytotechnician until being slide preparations. Next the pathologist read the preparations with a microscope until a diagnosis is produced.

            Have you ever heard about pap smear? The public can conduct pap smear examinations anywhere, such as puskesmas, midwives / doctors practicing independently, clinics and hospitals. But those who analyzed and read the pap smear specimen were pathologists, not midwives or other doctors.

           Besides pap smears, what other types of examinations are performed in pathology lab? In principle, what is analyzed in pathology lab is the cells or tissues of the body. So the specimen examined very vary.

            To assess cells, the material examined may be urine, joint fluid, pleural fluid (abnormal fluid in the cavity of the pulmonary membrane), ascites fluid (abnormal fluid in the abdominal cavity), etc., according to the site of the disease. For example, if a tumor in the bladder is suspected, the material being examined is urine. If there is a suspected tumor in the lungs that has spread to the pleural cavity, the material examined is pleural fluid, and so on. Cell examination of these materials is called cytological examination. Pap smear is also one of example included in this examination category. Another example is Fine Needle Aspiration or Fine Needle Aspiration Biopsy (abbreviated as FNA or FNAB, respectively). This type of biopsy is done to get an initial diagnosis, by aspiring or suctioning the contents of the tumor or tissue using fine needles with certain techniques.

            For tissue examination, or in medical terms is called histopathological examination, the material may be obtained by biopsy or surgery. Biopsy means taking a small part of a tumor or any lesion at body tissue. This biopsy is done to establish the diagnosis so that patients can be given appropriate treatment. Surgery means removing all the tumors or body tissues or organs that have lesions. The purpose of histopathological examination of the surgical specimen is to make a more detailed diagnosis (type, subtype), to determine the severity of the disease and the extent of the spread of the disease. In cancer patients receiving radiation therapy and/or chemotherapy, histopathological examination is also used to assess the response of therapy.

            Pathology examination has been progressed. In addition to cytological and histopathological examinations, one other type of examination that is quite routine at present is the immunohistochemical (IHC) examination. The IHC uses histopathological examination specimen which is archived in the paraffin blocks (a type of wax). The IHC is generally done in cases of tumors/cancers and is carried out for several indications, such as, to establish a diagnosis of difficult cases that cannot be diagnosed by histopathological examination and to identify proteins used as guidelines for the selection of therapy.

            In addition to playing a role in patient care, the pathology lab is also an important storehouse of research. The tissue embedded in paraffin blocks archived in pathology lab is widely used to study various aspects of the disease, such as understanding the causes, the process of disease occurrence, diagnosis and the course of the disease.

            Nowadays the importance of the role of the pathology lab is being increasingly realized. Study program to graduate pathologist is increasingly in demand. In Indonesia there are already scattered centers of pathology study program, including at the Faculty of Medicine of Udayana University. Many hospitals have begun recruiting pathologists and make their own pathology labs so that the distribution of pathology examination services is more even and affordable.