Anatomopathology: Definition, Structure, Pathophysiology, Pathology and Anatomo-Pathological Procedures

It is a unique medical discipline at the intersection of clinic, biology and image.

It is an essential step for diagnosis, especially in cancer cases.

It uses a lot of complementary techniques, such as molecular biology methods, chromogenic in situ hybridization or fluorescence in situ hybridization.

Currently, the demand for new diagnoses that use cytology and anatomy approaches increases rapidly.

These growing needs range from scanning, visualization, image management, annotation, quantification and, finally, the generation of reports.

Pathological anatomy or anatomopathology studies the structural alterations ( anatomical lesions ) of the body and its organs and tissues and how this relates to function and contributes to the development of the disease.

They cover the study of the normal and abnormal morphology of the body at macroscopic and microscopic levels.

The emphasis in anatomy is on understanding how the structure is related to the function in the organism and in pathology it is about developing an understanding of the causes, the mechanisms of development and the consequences of the disease.

Structure

Each organ of a body consists of four basic types of tissues: epithelial, connective, muscular and nervous tissue.

However, the cells in these tissues can be formed differently when they are found in different organs.

In fact, the way how cells form a tissue can predict how that tissue works.

This is because the same patterns of structure and function are repeated throughout the body.

Some tissues provide a rigid support to the structure, such as bone; others contract to the general force of movement, like skeletal muscle; while others form pockets that secrete fluids, such as the salivary glands.

Pathophysiology and pathology

Diseases occur because normal tissues are damaged or do something wrong.

Pathology and pathophysiology are the study of malformed diseases and tissues with the hope of understanding their causes and possible treatments.

The pathology examines how a tissue has an abnormal shape.

Pathophysiology examines how a tissue abnormally produces molecules and fluids.

Neither the pathology nor the physiopathology would be possible without histology, since a researcher would not recognize the abnormal without knowledge of what is normal

Pathological anatomy is a discipline that combines fundamental sciences and clinical practice.

The information acquired by studying the morphological changes of organs, tissues and cells induced by pathological processes and human diseases serves as a basic knowledge for the further development of essential diagnostic and treatment skills.

The general sections (associated with pathological processes) and systemic, nozological (associated with diseases) sections of the pathological anatomy are studied.

Activities and procedures Anatomo-Pathological

Biopsies

A biopsy is a medical procedure in which a tissue sample is taken from a patient for examination and diagnosis of a disease or medical condition.

There are many different biopsy procedures depending on the location of the tissue being investigated, which include:

  • Bone marrow biopsy: A small sample of bone marrow (usually hip) is removed through a thin needle. This type of biopsy helps diagnose diseases such as leukemia.
  • Colposcopy-directed biopsy: A colposcope is a small microscope used to examine a woman’s cervix while taking a tissue sample and helping to diagnose based on the results of the Pap test.
  • Endoscopic biopsy: The endoscope is a flexible tube that can be inserted into a hole (such as the mouth or anus) or through a small incision in the skin. Once the mass is reached, the cutting tools are threaded through the endoscope so that a tissue sample can be taken.
  • Needle biopsy: A small sample of the tumor is removed with a thin hypodermic needle. This can be done with or without local anesthesia. This type of biopsy can be used to diagnose conditions of the liver or thyroid.
  • Puncture biopsy: a special tool is used to drill a hole through the upper layers of the skin. The anesthetic used can be local or topical. This type of biopsy can help diagnose various skin conditions.
  • Stereotactic biopsy: a series of x-rays help guide the surgeon’s needle to the lump. This type of biopsy is usually done when the lump is difficult to see or feel.

Anatomical pathology and cytology

The DNA is extracted from the patient’s tissue, the hormone receptor assays are performed on paraffin-embedded tissues and fixed with formalin.

The tests are:

  1. Analysis of hormone receptors of all cases of breast carcinoma such as: estrogen, progesterone and HER2 gene receptors.
  2. Amplification assays of the HER2 gene by in situ fluorescent hybridization, in selected cases of breast carcinoma, UroVysion FISH assay to help diagnose recurrent bladder carcinoma in urine samples.
  3. Microsatellite instability assays to detect patients with colorectal carcinoma due to possible inherited genetic defects.
  4. Quantification of DNA in hidatidaphic moles and subtyping of genital and cervical lesions for the human papillomavirus, to identify patients at high risk of developing cervical cancer.
  5. Diagnosis of skin diseases, neoplasms of soft and haematopoietic tissues, systemic diseases that can affect the skin, thanks to histology and routine optical microscopy.

Cytogenomics

This includes the analysis of amniotic fluid, chorionic villi, bone marrow , peripheral blood, fetal blood, solid tumors and other tissues.

Tests are used such as chromosomal analysis of amniotic fluids, bone marrow aspirates, chorionic villus biopsies, solid neoplastic tissue, oncological blood, peripheral blood, products of conception, cytogenetic tests.

Also oncological, prenatal tests, special stains to identify chromosomal variants, tissue culture of the patient to provide cells for analysis and biochemical tests, fluorescent in situ hybridization tests, complete chromosomal markers or chromosomes of unknown origin.

These procedures are useful for detecting chromosomal abnormalities associated with microdeletion and microduplication syndromes, hematological disorders and detection of prenatal aneuploidy.

Electron microscopy

This involves fixing the tissue, embedding the sample in epoxy polymer, sectioning the tissue at approximately 700 Angstroms, staining with heavy metals, examining the samples and recording images representative of the tissue.

Electron microscopy can be seen as an extension of routine optical diagnostic techniques.