Clinical PATHOLOGY BY: - PowerPoint Presentation

Slide1

Clinical PATHOLOGY

BY:

DR (MRS) B.J.THANENTRHIRAN(MBBS)Slide2

Pathology is the study (logos) of suffering (pathos).

Pathology address following components of disease.

Cause /

Etiology

Incidences

Mechanisms of development (

pathogenesis

)

Structural alterations of cells (

morphologic changes

)

Consequences of changes (

clinical manifestations)Slide3

Pathology

Anatomic pathology Clinical pathologySlide4

Anatomic pathology is concerned with the diagnosis of disease based on the gross, microscopic, chemical, immunologic and molecular examination of organs, tissues, and whole bodies (autopsy).Slide5

Clinical pathology

is concerned with the diagnosis of disease based on the laboratory analysis of

body fluids

and tissues

using the tools of Chemistry Microbiology Hematology

and Molecular pathologySlide6

Subsections

Anatomic pathology

Cytopathology

Histopathology

Surgical pathologyClinical pathologyHematology

Chemical pathology

Microbiology

Immunology

Urinalysis

Blood bankSlide7

Cytopathology

is a branch of pathology that studies and diagnoses diseases on the

cellular

level.Histopathology refers to the microscopic examination of

tissue

in order to study the manifestations of disease.

Surgical pathology

involves the gross and microscopic examination of surgical specimens and biopsies.Slide8

Cytopathology / cytology

Cell collection

Exfoliative cytology

Cells from spontaneous exfoliation

Cells from mechanical exfoliation(scraping/brushing)

Intervention cytology

Intervening into the body for sample collection

FNAC – Fine Needle Aspiration CytologySlide9

Indications for cytopathology

Diagnosis of malignancy and its type

Diagnosis of premalignant diseases

Detection of inflammation and certain types of pathogenic agents

Study of the hormonal patterns and evaluation of the

gonadal

hormonal activity.Slide10

Follow-up and monitoring of response to chemotherapy and irradiation.

The identification of sex chromosome

. (Barr bodies)

Tumor

markers study on cytological specimensSlide11

Following parameters are seen in the cellular samplingNucleus

Nucleolus

cytoplasm

In addition following pathologies can be seen.

Microbial infectionsReactive changesImmune reactionsCell agingAmyloidosis

Autoimmune diseasesSlide12

Cytology specimens

Fluids

Effusion into body cavities (pleural, peritoneal, pericardial)

Cyst aspirates

CSF

Urine

Sputum Slide13

Wash specimens – bronchial, bladder

Brush cytology – bronchial, cervical, gastro intestinal.

Pap smears

Bone marrow aspiration

Fine needle aspiration.Slide14

Advantages of cytology

Provides a rapid, inexpensive & simple diagnosis.

Little tissue injury.

Frequent sampling

Evaluation of progression to treatment / recurrenceBetter accepted by the patient & clinicianSample cells from wider surface than a biopsySlide15

Cells can be obtained by inaccessible / difficult to access areas

Determination of hormonal states

Minimum distortion of cells

Smears permit better evaluation of the nature of inflammations and infections.Slide16

Limitations of cytology

Cytologic

diagnosis is not always final. Must be confirmed by histology.

Diagnosis is based upon the study of minute cellular details.

Tissue pattern cannot be appreciatedInterrelation & arrangement of the cells to the supporting stroma cannot be established.

Location of lesion cannot be pin pointed (except in FNAC)Slide17

Size of the lesion cannot be estimated.

Error / misinterpretation may occur.Slide18

Fine Needle Aspiration Cytology (FNAC)

Used to investigate superficial lumps or masses.

Lung, intra-abdominal and retroperitoneal samples can be taken with the help of radiologic imaging (CT, ultrasound)

Sampling is done for diagnostic purposes and to asses the effect of treatment.Slide19

Advantages of FNAC

Easy, reliable, cost effective

Out

patient

procedureMinor surgical procedure, No risk of anesthesia

Safer

than open surgical biopsies

Easily

repeatable

Less

complications

Patient

can go back to normal activities soon

Can

get results rapidlySlide20

Disadvantages of FNAC

False negative

results (some lesion do not exfoliate cells well, needle may miss the site of the lesion, timi

d collection, inadequate negative pressure).

Definitive diagnosis is difficult.Slide21

Complications of FNAC

Needle trauma

Needle track seeding - testicular tm,

chondrosar

HematomaPainSlide22

Preparations before the procedure

No use of aspirin or non-steroidal anti-inflammatory medications (e.g. ibuprofen, naproxen) for one week before the procedure

No food intake a few hours before the procedure

Routine blood tests (including clotting profile) must be completed two weeks before the biopsySlide23

Suspension of blood anticoagulant medications

Antibiotic prophylaxis may be instituted.

Check vital signs before the procedure

IV line if necessary.Slide24

Equipments needed for FNAC procedure

Syringes

Standard disposable plastic syringes of 10ml are used.

Syringe should be of good quality and should produce good negative pressure.

Needles

Standard disposable 22-24 gauge 1-1½-inch needles are used for plain FNAC.Slide25

Slides

Plain glass slides of good quality are used. Slides should be clean, dry, transparent and grease free.

An important procedure is slide labeling at the time of sampling.

Fixatives

These are applied to the smears as a spray or by immersion of the slide into a liquid.

The most commonly used is 95 % Ethanol.

This inexpensive readily available liquid provides excellent cytological details.

Fixative is kept ready in

Coplin

jars.

Container Slide26

Other supplies

Test tubes, pencil for marking, alcohol, swabs for skin, watch glass, saline, adhesive dressing, gloves etc. are needed.

All the materials required are assembled in advance before starting the procedure.

This is extremely important as delay in fixation can make interpretation of smears difficult.Slide27

Steps to be followed before performing the aspiration

Relevant history and clinical details, radiological findings, provisional diagnosis etc. must be entered in the requisition form. Site of FNA must be clearly stated.

Lesion to be aspirated is palpated and its suitability for aspiration assessed. The appropriate needle is selected accordingly.Slide28

The procedure must be clearly explained to the patient and consent and co-operation ensured. Patient may be anxious which needs to be allayed. Ignoring this simple but crucial step can result in failure.

Before starting the procedure, ensure that all the required equipment, instruments and supplies are available.

All universal precautions should be followed during the procedure.Slide29

Steps to be followed during the aspiration

Position the patient.

Sterilize the skin above the area to be biopsied with antiseptics.

May use local anesthesia but often not necessary.

Locating the mass by palpation by non dominant hand.Slide30

Aspirates should be obtained using preferably a 23 gauge, 1 ½ inch disposable needle mounted on a 10 ml plastic syringe, held by the dominant hand.

The needle should be gently introduced through the skin passing to the level of the dominant mass.

Having confirmed the position of the needle within the mass, negative pressure should be created within the syringe by pulling back the plunger.

The needle should move back and forth through the mass, in different rotational directions.Slide31

Suction should be maintained throughout the process by outward.

All suction should be released before removing the needle from the mass.

Then the needle should be withdrawn gently from the mass.

To limit hematoma formation from the site of the puncture, firm pressure should be applied with a piece of cotton for two minutes.Slide32

Preservation and processing of Smears

Smears are prepared and fixed according to the requirements of the stain to be used.

Air-drying followed by hematological stains.

Alcohol fixation followed by

Papanicolaou

(pap) or

hematoxylin

and eosin (H&E) staining.Slide33

Preparation and fixation for pap/ H&E staining

Immediately after withdrawing, detach the needle, draw air into the syringe, reattach the needle and express the material in the needle onto a slide.

Needle tip is brought into light contact with the slide and the aspirate is carefully expressed without spraying into the air, which can cause air-drying and also can form aerosols, which are potentially infectious.

Aspirates are smeared immediately using another slide or cover slip or with the needle itself and dropped into the fixative.Slide34

The cells must be delicately and thinly smeared with minimal distortion and fixed according to the stain to be used.

Spreading the cells too thinly as well as preparing too many smears is an error because of cellular distortion or dilution. Thus the smears must be of adequate thickness.Slide35

Unsatisfactory smears can be due to non representative / inadequate samples or due to poor quality of preparation (thick smears, extreme admixture with blood, delayed fixation, over staining etc)Slide36

Quality control Measures

In addition to details of technique (procedure, preparation, quality of materials used) and clinical correlation; other routine quality control practices regarding specimen reception (checking patient details, identification of slides, number of slides from each patient, labeling the slides), preparation and maintenance of stains, staining procedure, mounting, record keeping etc. are needed for optimal quality of diagnosis.Slide37

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