Histopathologic and Cytologic Techniques PDF

HISTOPATHOLOGIC AND CYTOLOGIC TECHNIQUES Laboratory Prof. Peter Samonte | A.Y. 2024-2025| 3rd Year 1st Semester | Prelim LESSON 2: PATHOLOGY AUTOPSY...

HISTOPATHOLOGIC AND CYTOLOGIC TECHNIQUES Laboratory Prof. Peter Samonte | A.Y. 2024-2025| 3rd Year 1st Semester | Prelim LESSON 2: PATHOLOGY AUTOPSY “Autopsia” - to see with one’s own eye HUMAN PATHOLOGY It is usually performed by a specialized medical doctor called pathologists 1. GENERAL PURPOSES ❖ Is concerned with the basic reactions of cells and tissues ➔ To establish the cause of death to abnormal stimuli that underlie all diseases ➔ To interpret and correlate facts surrounding death ❖ Deals with the general principles of disease ➔ To identify the decedent (decease) ➔ To establish the time of death ➔ To reconstruct the events surrounding the infliction of 2. SYSTEMIC injury ❖ Organ and organ system pathology ➔ To collect evidence in cases of questionable death ➔ Role of the medical technologist in autopsy ❖ Examines the specific responses of specialized organs ➔ To process the collected specimen and tissues to more or well - defined stimuli ➔ To assist in the collection of specimen ❖ Includes the study of diseases pertaining to the specific ➔ To maintain the quality control in the record and specimen organs and body system. materials ➔ To dispose the analytes DIGITAL PATHOLOGY TYPES OF AUTOPSIES ➔ Includes two disciplines: 1. MORPHOLOGICAL DISCIPLINES CLINICAL AUTOPSY ❖ Involves application of microscope as an essential tool for ❖ Done on a patient that has died while under the care of a the study hospital or clinical staff and in cases where the physicians ❖ Includes histopathology, cytopathology, and hematology have failed to identify the cause of a sudden death ❖ Histopathology (used synonymously with anatomic pathology) FORENSIC AUTOPSY ❖ Deals with the study of disease in a tissue section ❖ Performed when a corpse has been retrieved from a crime or murder site SUBDIVISIONS OF ANATOMIC PATHOLOGY ❖ This autopsy will reveal any trace of bullets, blows, or injuries and poison in the system SURGICAL PATHOLOGY ACADEMIC AUTOPSY ➔ Deals with the study of tissues removed from the living body by biopsy or surgical resection ❖ Performed by medical students to teach them about human anatomy EXPERIMENTAL PATHOLOGY ❖ May be used for research purposes ➔ Defined as production of disease in the experimental animal and study of morphological changes in organs AUTOPSIES TECHNIQUE after sacrificing the animal ➔ It is done for research. The most common animal for experiment is the Mice. VIRCHOW TECHNIQUE ❖ The organs are removed one by one (individually) and FORENSIC PATHOLOGY AND AUTOPSY WORK dissected as they are removed ➔ Includes the study of organs and tissues removed at post mortem for medico legal work and for determining the ROKITANSKY TECHNIQUE underlying sequence and cause of death ❖ Organs are removed based on convenience 1 HISTOPATHOLOGIC AND CYTOLOGIC TECHNIQUES Laboratory Prof. Peter Samonte | A.Y. 2024-2025| 3rd Year 1st Semester | Prelim ❖ Removal is done partly en bloc FOUR POST MORTEM SIGNS USED IN TELLING THE TIME ❖ Dissection is done in situ OF DEATH ❖ Pathologies are correlated EN MASSE (LE TULLE) TECHNIQUE 1. PALLOR MORTIS ❖ En masse (all at one time) removal of organs of the ❖ As the heart stops beating the circulation of blood thoracic cavity, abdominal cavity, and pelvic area and throughout the body decreases. The organs farthest subsequently dissected into organ blocks away from the heart like the skin stop receiving blood ❖ It preserves the blood supply as well as the relationship ❖ This gives the corpse the pale and lifeless appearance of the organs to each other that was associate with death ❖ The cadaver can be released immediately ❖ This paleness which appears 15 to 30 minutes after ❖ Difficult to do without an assistant death is called pallor mortis. It is one of the most ❖ The pathologist deal with a very large number of organs identifiable signs of death. at a time ❖ Namumutla yung body nung patient. ❖ All organs are removed from the cadaver, examined grossly, weighed and measured 2. ALGOR MORTIS ❖ Humans are homeothermic which means we maintain a EN BLOC (GHON / ZENKER) TECHNIQUE constant internal body temperature, ❖ The physically related organs (organ bloc) are removed ❖ The circulatory system is an important mechanism by at the same time (e.g., the thoracic block, the celiac which humans maintain an average internal temp of 37 block, the urogenital block) degree Celsius. ❖ It preserves the anatomic relationship among organs ❖ Heat is produced primarily through various metabolic without the unwieldy mass of organs processes happening in and put the body. ❖ The pathologists deals with a large number of organs at a ❖ This produced heat is dissipated in deeper organs such time as the liver and brain and to other parts such as the skin ❖ The organs comprising a bloc are removed from the through the movement of blood. cadaver, examined grossly, weighed and measured ❖ Requires skill to remove an intact block of organs 3. RIGOR MORTIS ❖ This sign is one of the most important signs in calculating TIME OF DEATH time of death The time of death is not exact time the person had died ❖ Rigor mortis literally means stiff death but instead a time frame in which a person could have ❖ It is the contraction of the muscles in the body after death died based on the evidence presented ❖ Before rigor mortis all the muscle relax which is called the Forensic scientists calculate time of death with different primary flaccidity. techniques. The first go- to- method is to study the ❖ This happens because brain activity decreases until it physical changes of the body after death stops. Without the brain giving muscles the signal to Four Postmortem signs used in telling the time of death: contract, the muscles will remain relaxed. Primary ○ These are physical and observable changes in the flaccidity will last 1-2 hours after time of death. body at the first 24 to 48 hours after the heart stops ❖ The first muscles to relax are the ones at the eyelids, beating and the nervous system shuts down fingers, and toes. In this stage the corpse usually ○ These four signs are commonly used together to releases urine and gas because the muscles controlling estimate the time of death urination and passing of gas are relaxed. ○ Time of death is not 100% accurate because of other ❖ Primary flaccidity is followed by rigor mortis where factors such as the environment, weather, clothes, or muscles stiffen up because of cells being broken down by whether the victim was moved digestive enzymes. This cellular breakdown is a normal part of body decomposition and is called autolysis. ❖ Rigor mortis start in the same order as the primary flaccidity does; first with the eyes and fingers then slowly progresses to the body 2 HISTOPATHOLOGIC AND CYTOLOGIC TECHNIQUES Laboratory Prof. Peter Samonte | A.Y. 2024-2025| 3rd Year 1st Semester | Prelim ❖ Rigor mortis reaches its peak at 12 hours postmortem, LATE POST - MORTEM CHANGES after that the muscles begin to relax in the same order that they began contracting ❖ After the rigor mortis, a second cycle of relaxation called 1. AUTOLYSIS (SELF - DESTRUCTION) secondary flaccidity which is due to muscle degeneration ❖ Digestive enzymes breakdown the proteins in the ❖ Is an intrinsic activity brought about by the breakdown of muscles including the muscle contracting machinery cells and tissue of the human body because of the ❖ Forensics experts used this progression of relaxation and constituents of the said cells. stiffening to estimate the time of death a. Just after death, the cell membranes breakdown and release enzymes that start self-digestion. The first external sign of autolysis is the whitish appearance 4. LIVOR MORTIS of the cornea. ❖ After death, blood is subjected to the forces of the gravity ○ On autopsy, the doughy appearance of the now that the heart is not moving it around any longer. It parenchyma of the pancreas and lungs appears pulls wherever the forces of gravity is strongest. This is within hours of death. called lividity or hypostasis. b. Autolytic fermentation in the unborn fetus within the ❖ This starts about 15 to 30 mins after death and starts to amniotic cavity is termed as maceration and become visible 2 hours after death. characteristically demonstrates as slippage of skin ❖ Lividity starts to become fixed after 6 hours as the blood with blackish-brownish discoloration of the underlying vessels begin to breakdown tissues. ❖ After 8-12 hours a purple coloration develops, this purple ○ The process of autolysis is devoid of any coloration develops because deoxygenation of bacterial action. hemoglobin forms deoxyhemoglobin which has a purple- blue color. This coloration can be very useful in 2. PUTREFACTION determining the time of death. Once lividity is fixed it doesn’t fade even when the body is moved. ❖ Is the decomposition of the body carried out by the ❖ If the part of the body comes in contact with a firm microbial action. surface that obstructs the blood flow an impression of it a. After cessation of homeostasis, the natural flora of will show on the skin that is surrounded by a pool of the body migrates from the gut to the blood vessels blood. and spreads all over the body. ❖ The color or pattern of lividity can allow forensic scientists ○ External micro-organisms enter the body to guess not only what the time of death could be but also through the alimentary canal, respiratory tract, the cause of death and open wounds. In the absence of body ❖ Lividity on the extremities such as the fingers would defense/immune mechanisms, the microbes suggest that the body was upright keep growing, as they feed upon the proteins ❖ Lividity developed on the back would suggest a and carbohydrates of the blood and body parts. horizontal position ○ The principal bacterial agent causing putrefaction is the gram-positive, anaerobic, and rod-shaped Clostridium welchii. SHIFTING OF POST - MORTEM LIVIDITY ○ It releases lecithinase, which causes hydrolysis ➔ Any change in the position of the body causes blood to of lecithin present in the blood cells, causing settle down in the newer dependent areas, referred to as their lysis. “shifting of postmortem lividity”. ○ Putrefaction begins within an hour of death, but ◆ However, this shifting may not be possible after 6 to the peak activity of the microbes occurs around 8 hours of death, due to postmortem coagulation of the 24-hr time frame. blood accumulated in the dependent areas of the b. The first external sign of putrefaction is the greenish body. This phenomenon is termed as “fixation of postmortem staining”. Whether or not lividity is fixed discoloration of the skin over the right iliac fossa, the is determined by the blanching test. region overlying the caecum, the contents of which ➔ Pressure is applied to the livid area by the thumb of the are mostly liquid and are full of bacteria. observer for about a minute, then released. If the area ○ The greenish discoloration gradually spreads to underneath the thumb becomes pale on the removal of the abdomen and involves the entire body in pressure, the lividity is said to be not fixed, while if the later stages. region stays stained after removal of pressure, the lividity is said to be fixed. 3 HISTOPATHOLOGIC AND CYTOLOGIC TECHNIQUES Laboratory Prof. Peter Samonte | A.Y. 2024-2025| 3rd Year 1st Semester | Prelim TWO MODIFICATIONS OF PUTREFACTION 1. ADIPOCERE FORMATION a. Saponification or adipocere formation is a medication of the putrefaction process, which involves hydrolysis and hydrogenation of fatty tissues into a yellowish, greasy, rancid, wax-like substance called adipocere b. The formation of adipocere requires the body to decompose in a warm, moist, and humid environment as water is a prerequisite for hydrolysis of fats. It can occur as early as in three weeks, but usually, it takes three months to form. Adipocere initially is yellow and soft, but after a few months turns white and brittle. 2. MUMMIFICATION a. Modification of the putrefaction process characterized by the desiccation or dehydration of the cadaveric tissues. b. Skin of the deceased becomes brown, hard, and brittle and has stretched appearance over prominences like the zygomatic bones, mandible, etc c. Requires a dry arid environment with a constant warm breeze to materialize. The body needs more time for mummification than adipocere formation. Partial mummification can be seen to co-exist with other putrefactive changes in different parts of the same body 4