Histopathological Techniques in Pathomorphological Diagnostics PDF
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This document describes histopathological techniques used in pathodiagnostics, including intraoperative (frozen section) and postoperative procedures. It explains the principles and steps involved in each technique, as well as their limitations and applications.
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Histopathological Techniques in Pathomorphological Diagnostics istopathology is thestudyof diseased tissues atthe microscopic level, which plays a crucial rolein diagnosing diseases by H examiningtissue architectureandcellular details.Pathomorphological diagnostics utilis...
Histopathological Techniques in Pathomorphological Diagnostics istopathology is thestudyof diseased tissues atthe microscopic level, which plays a crucial rolein diagnosing diseases by H examiningtissue architectureandcellular details.Pathomorphological diagnostics utilises histopathological techniques to identify abnormalities in tissues and cells, often aiding in identifying cancers, infections, and inflammatory conditions. o basically, Histopathology involves studying diseased tissues at the microscopic level to observe changes in the structure S and cellular details.Pathologistscompare the histologicalfeatures of healthy and diseased tissues to diagnose conditions, determine the extent of the disease, and identify abnormalities like infections, cancer, or inflammation. This 1. Introduction to Pathological Techniques athological techniques involve thepreparation andexaminationof tissues toassess any pathological(d isease-related) P changes. They can be classified into several typesbased on when they are performed: Types of Histopathological Procedures: Intraoperative (Frozen Section):It is a fast techniqueused during surgery to give doctors immediate information about a tissue sample. It is performed during surgery to guide immediate clinical decisions. Tissue is quickly frozen, sectioned, stained, and analysed by the pathologist. What is it? uring surgery, if a surgeon wants to know something specific about a piece of tissue—like whether it’s cancerous or if D they’ve removed enough of a tumor—they take a small sample of the tissue and send it to the pathologist. The pathologist uses thefrozen sectiontechnique to analyse it quickly,often within 15-20 minutes, while the patient is still in surgery. How does it work? 1. reezing the Tissue: The tissue is rapidlyfrozenusing a machine called acryostat. Freezing makesthe tissue hard F enough to cut very thin slices. . 2 Sectioning: Thin slices of the frozen tissue are cutusing the cryostat. 3. Staining: The slices arethen stained with dyes(likeHematoxylin and Eosin) tohighlight the cells andtissue structure, making them visible under the microscope. 4. Microscopic Examination: Thepathologist quickly looksat the tissue under a microscope to provide information to the surgeon. Why is it done? I mmediate Diagnosis: It helps surgeons make decisionsright during the surgery. For example, if the tissueis cancerous, the surgeon might remove more tissue. If the tumor margin is clear (no more cancer cells at the edge of the tissue), the surgery might stop there. Saves Time: It avoids the need for another surgeryby confirming diagnoses or treatment options right away. Limitations: ot as detailed: Frozen sections are not as perfectas regular (postoperative) tissue processing because freezing N can sometimes distort the tissue a bit. But it’s goodenough forurgent, on-the-spot decisions. Not for all tissues: Some types of tissues, like fattytissues,may not freezewell and can be harder toevaluate. In short: I t’s like aquick test during surgerythat allowsthe surgical team to make important decisions in real-time, without having to wait for the full, detailed tissue analysis that comes after the surgery. he intraoperative frozen section process is a method used by surgeons and pathologists to make quick, on-the-spot T determinations concerning the pathology of a specific tissue. They use it to make on-the-spot diagnoses and decisions, such as whether a patient requires the removal of a portion of infected tissue or not. How it works: They take a piece of tissue and send it to pathology. Pathology then freezes the tissue (in a cryostat) so that it can be easily cut into tiny slices. They next stain the thinly cut sections with dyes (such as eosin and haematoxylin). They next compare the sample tissues with healthy tissues. he reason they do this is so that, for example, if the infected patient is in surgery, the surgeon can either continue the T process (by cutting the rest of the diseased area during surgery) or leave it alone if it is not infected. As a result, its ability to perform in emergency situations is a plus, but one of its downsides is that it is not as detailed as post-operative care because it requires less time. Despite this, it remains helpful for making on-the-spot/urgent diagnoses.. Postoperative (Routine Histopathology):Tissue isprocessed and examined after surgery using standard methods. Purpose:Provides detailed and accurate diagnosisof removed tissues (e.g., tumor analysis). Postoperative (Routine Histopathology) Procedure: ostoperative histopathology, also known asroutinehistopathology, refers to the detailed examinationof tissue that is P removed during surgery after the procedure is completed. Here’s how the process works in simple terms: What is the Goal? he goal of postoperative histopathology is to thoroughly analyse the tissue under a microscope to figure out what disease is T present, how advanced it might be, and whether or not the surgical procedure successfully removed the diseased tissue. The issue is processed and examined after surgery using standard methods For example, if a surgeon removes a tumor, the pathologist will look at the tumor closely to see: I s it cancerous or benign? How aggressive the cancer is, if it’s present. If the tumor was completely removed (are the "margins" of the tissue clear?). Steps Involved in Routine Histopathology: 1. issue Collection:After surgery, the removed tissue(for example, a lump or part of an organ) is sent to the T pathology lab. This tissue could be anything from a small biopsy (tiny tissue sample) to a large specimen (like part of an organ). 2. Fixation:To prevent the tissue from rotting or breakingdown, it is placed in a special chemical called afixative (usually formalin). This helps preserve the structureof the tissue, keeping it as close to its natural state as possible. 3. Tissue Processing:After fixation, the tissue is preparedfor microscopic examination. Here’s how: ○ Dehydration:The water is removed from the tissueusing alcohol. ○ Clearing:The alcohol is replaced with a chemical(like xylene) that makes the tissue ready for the next step. ○ Embedding:The tissue is placed inparaffin wax, whichhardens and provides support, making it easier to cut. 4. Sectioning:The tissue block is sliced into ultra-thinsections (like 3–5 microns thick). These slices are placed on glass slides. Kinda like slicing a loaf of bread super thin! 5. Staining:Since tissues are mostly transparent, theyneed to bestainedwith special dyes to see the differentparts clearly under the microscope. The most common stain used isHematoxylin and Eosin (H&E), which colorsthe nuclei of cells blue/purple and the rest of the tissue pink/red. 6. Microscopic Examination:Apathologistlooks at thestained slides under a microscope. They will compare the tissue with normal (healthy) tissue to spot any abnormalities. They may look for: ○ Unusual cell shapes and sizes. ○ The way the cells are organised. ○ Whether there are signs of cancer, infection, or inflammation. 7. Report Generation:After carefully analysing the tissue, the pathologist writes areport. This report includes: ○ Diagnosis(e.g., cancer, benign growth, inflammation). ○ Description of how severe or advanced the disease is. ○ Comments on whether the tumor or diseased tissue was completely removed. 8. Communication with Surgeon:The pathologist sendsthe report to the surgeon or treating doctor, who then uses this information to plan the next steps in patient care, such as further treatment, additional surgery, or no further action if all is clear. Summary: hepostoperative procedure,also known asroutinehistopathology, isa detailed process used to examine tissue samples T collected during surgery. It helps pathologists determine whether the tissue is benign or cancerous, assess the severity of the disease (such as the stage of cancer), and check if the entire tumor has been removed. The procedure involves eight steps: First, the surgeon collects the tissue, then it is fixed in a solution like formalin to preserve its structure for laboratory analysis. In the lab, the tissue undergoes processing, which includes dehydration (removing water using alcohol), clearing (replacing the alcohol with a solution like xylene), and embedding (hardening the tissue in paraffin wax to make it easier to cut). Next, the tissue is sectioned into thin slices, which are then stained using dyes such ashematoxylin(to colour the nuclei blue/purple) andeosin(to stain the cytoplasmpink/red). This staining allows for easier examination under a microscope, as unstained tissues are nearly transparent. The pathologist then conducts amicroscopic examination, identifying any abnormalities in the cells, such as changes in size, shape, or number. Finally, a report is written detailing the findings, and the pathologist consults with the surgeon to inform them of the results and guide any further treatment decisions
