Histology is the study of the normal microscopic morphology (shape) of tissue eg skin, kidney, breast, etc. Histopathology is the study of the abnormal morphology of tissue which occurs when the tissue is diseased.
Using an example of a skin lesion (disease), a Medical Practitioner will remove part or all of the diseased area and send the tissue fragment, called a biopsy, to the laboratory. In the laboratory the biopsy is processed to enable thin sections (4 microns in thickness) to be cut. The sections are placed on a glass slide, stained and handed to a Histopathologist for examination. The Histopathologist will determine the diagnosis (type of abnormality) and, if necessary, indicate a cause. Consultation often takes place between the Histopathologist and the referring Medical Practitioner.