Anatomopathology, Anatomical Pathology (Commonwealth) or Anatomic Pathology (U.S.) is a medical speciality that is concerned with the structural alterations (anatomical lesions) of the body and its organs and tissues, and how this relates to function changes and contributes to the development of the disease.
It is based on the normal and abnormal morphology of the organism at macroscopic and microscopic examination (histological and cytological). The emphasis in anatomy is on understanding how structure relates to function in the organism; while in pathology it is about developing an understanding of the causes, the mechanisms of development and the consequences of the disease.
The ultimate purpose of this specialty is the correct diagnosis of biopsies, surgical pieces, cytologies and autopsies/necropsies. In the case of human medicine, the essential study field are the human diseases; on the other hand in veterinary medicine, diseases that affect pets and supply animals are sought, as well as those zoonotic diseases of possible transmission to humans.
It is an essential step for diagnosis, especially in cancer cases.
- Gross examination: the examination of diseased tissues or corpses with the naked eye. This is important especially for large tissue fragments, because the disease can often be visually identified. It is also at this step that the pathologist selects areas that will be processed for histopathology.
- Histopathology: the microscopic examination of stained tissue sections obtained by paraffin inclusion or freeze slides.
- Cytopathology: the examination of loose cells spread and stained on glass slides, taken by skin scrape or fine-needle aspiration cytology (FNAC)
- Histochemistry: the science of staining tissue sections using histological techniques. The standard stain is haematoxylin and eosin, but many others exist (PAS, Giemsa, ZN…)
- Immunohistochemistryv the use of antibodies to detect the presence, abundance, and localization of specific proteins of cells or etiological agents. This technique is critical to distinguishing between disorders with similar morphology, as well as characterizing the molecular properties of certain cancers.
The histopathology is the Pathology specialization referred to the microscopic examination of tissue in order to study the manifestations of disease.