Histopathology Techniques PDF

HISTOPATHOLOGY OLFU | College of Medical Laboratory Science  UNIT OUTCOME 1. Define Histopathologic Techniques 2. E n u m e r a t e a n d e x p l a i n t h e d i f f e r e n t s t e p s i n histopathologic techniques 3. Discuss Specimen collection 4. Explain the...

HISTOPATHOLOGY OLFU | College of Medical Laboratory Science  UNIT OUTCOME 1. Define Histopathologic Techniques 2. E n u m e r a t e a n d e x p l a i n t h e d i f f e r e n t s t e p s i n histopathologic techniques 3. Discuss Specimen collection 4. Explain the maintenance of equipment in histopathology 5. Explain the different cytologic specimens  HISTOPATHOLOGY HISTOPATHOLOGIC TECHNIQUES: involves different procedures that have been adopted for the preparation of materials and tissue for microscopic examination 12 steps in Histopathologic Techniques: 1.Numbering 7.Blocking 2. Fixation 8. Trimming 3. Dehydration 9. Sectioning 4. Clearing 10. Staining 5. Wax impregnation 11.Mounting 6. Embedding 12. Labelling  NUMBERING Basic information needed: 1. Date and time 2. Name of the patient 3. Specimen Number C- Cytology specimen A- Anatomical specimen S- Surgical specimen - Example: S-09-2111  I. NUMBERING Specimen source 1. Bilateral organs Examples: Extremities, kidneys, lungs and ovaries) 2. Miscellaneous Examples: age, sex, ward  RECEPTIONIST Validates if the specimen is adequate or good for tissue processing 1 person that will receive the specimen and put it into st the container CONTAINER: contain fixatives ✔Proportional to the size of the specimen ✔Clear ✔Unbreakable ✔Wide mouthed bottle  II. FIXATION Most critical step in histopathological techniques PRIMARY AIM: preserve the morphology and chemical constituents of the tissue. SECONDARY AIM: Protect and harden the specimen for further handling  EFFECTS OF FIXATIVES 1. Inhibit bacterial growth and reduce the risk of infections 2. Act as mordant or accentuator- accelerating the staining process  Types of fixatives (According to Actions) 1. Microanatomic Fixative Involves small tissue or organ 2. Cytological Fixative Involves body fluid or secretion 3. Histochemical Fixative Involves tissue containing labile substances  Types of fixatives (According to Compositions) 1. Simple Fixative Uses only on chemical for fixation 2. Compound Fixative The use of two or more chemicals for fixation  III. DEHYDRATION Utilizing chemical known as dehydrating agents Removing of intracellular and extracellular water and fixatives in the tissue EXAMPLES: 1. Alcohol- most commonly used 2. Acetone 3. Dioxane 4. Tetrahydrofuran 5. Cellosolve  IV. CLEARING Also known de-alcoholization Removal of dehydrating agent EXAMPLES: 1. Xylene- most commonly used 2. Toluene 3. Chloroform 4. Benzene 5. Cedarwood oil  V. IMPREGNATION T he p ro c e ss whe re b y the c l e ari ng ag e nt i s completely removed from the tissue and replace by a medium that will completely f il l all the tissue cavities. Also known as INFILTRATION PARAFFIN WAX IMPREGNATION PARAFFIN: the simplest, most common and best embedding medium used for routine tissue processing  VI. EMBEDDING Also known as CASTING OR BLOCKING The process by which the impregnated tissue is placed into a precisely arrange position in a mold containing medium which is then allowed to solidify FOUR TYPES OF TISSUE IMPREGNATION: 1. Parrafin wax 2. Celloidin 3. Gelatin 4. Plastic  VII. BLOCKING Allows the medium to solidify to produce tissue block  VIII. TRIMMING Process of removing excess wax after embedding Can use knife/blade or heated spatula  IX. SECTIONING Also known as CUTTING OR MICROTOMY T he p roc e ss by whi c h processed tissue is cut into unif orm ly thin slic es to fac ilitate studies under microscope MICROTOME: machine or instrument used for cutting sections of tissue  KINDS OF MICROTOME 1. Rocking Microtome Most simplest and oldest type of microtome 2. Rotary Microtome For cutting serial sections of tissue specimen 3. Sliding Microtome Most dangerous type of microtome  KINDS OF MICROTOME 4. Freezing Microtome For urgent surgical biopsies specimen 5. Cryostat Microtome Permits rapid penetration of tissue biopsies for surgical pathology Also known as COLD MICROTOME 6. Ultrathin Microtome Specimen for electron microscope  X. STAINING Tissue constituent are demonstrated in sections by direct interaction with dye or staining solution p rod uc i ng c ol orati on of the ac ti v e ti ssue component HEMATOXYLIN AND EOSIN STAINING Utilizes micro-anatomical studies of tissue It is a regressive staining method  XI. MOUNTING MOUNTING MEDIUM: the solution in which the specimen is embedded, generally under a cover glass. It may be liquid, gum or resinous, soluble in water, alcohol or other solvents and be sealed from the external atmosphere by non-soluble ringing media  Specimens for Examination I. Gynecologcial specimen Performed regularly even in pregnant women without undue risk EXAMPLE: Vaginal smear II. Non-gynecological specimen EXAMPLE: Respiratory Tract specimens: a. Sputum b. Bronchoalveolar lavage (BAL) III. Urine Determine the presence of urethral cancer  FERNING Arborization of mucus due to the formation of salt crystals in high NaCl concentration Exhibits “palm leaf appearance” THANK YOU FOR LISTENING !! OLFU | College of Medical Laboratory Science