Upload
fariha-hussain-nijhum
View
1.728
Download
1
Embed Size (px)
Citation preview
Principles of Tissue DiagnosisPrinciples of Tissue Diagnosis
Presented by-
Dr. Fariha HussainIntern DoctorSurgery Unit- 5ShSMCH
Definition of CellDefinition of Cell
Cell : The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing.
There are two basic types of cell :– Prokaryotic cell– Eukaryotic cell
Prokaryote Vs EukaryoteProkaryote Vs Eukaryote
Definition of TissueDefinition of Tissue
A tissue is an aggregation of cells, not necessarily identical, but from the same origin, that together carry out a specific function.
Animal tissues can be grouped into four basic types: 1. Connective tissue 2. Muscle tissue 3. Nervous tissue 4. Epithelial tissue
Four types of tissueFour types of tissue
Connective TissueConnective Tissue
Connective tissue is a fibrous tissue. It is the most diverse tissue and found
throughout the bodyHas 3 main components: Cells, Fibers,
and Extracellular matrix
Connective TissueConnective Tissue Connective tissue makes up a variety of physical
structures including:– tendons – the connective framework of fibers in muscles– capsules and ligaments around joints– cartilage– bone– adipose tissue– blood and lymphatic tissue
Connective TissueConnective Tissue
Functions of connective tissueFunctions of connective tissue
Providing structural framework for the body
Connection of body tissuesStorage of energyProtection of organs
Epithelial TissueEpithelial Tissue
Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands.
Structure of Epithelial TissueStructure of Epithelial Tissue
Cells in epithelium are very densely packed together like bricks in a wall, leaving very little intercellular space
The cells form continuous sheets which are attached to each other at many locations by tight junctions
Structure of Epithelial TissueStructure of Epithelial Tissue
All epithelial cells rest on a basement membrane, which acts as a scaffolding on which epithelium can grow.
Cell junctions are especially abundant in epithelial tissues. They consist of protein complexes that provide contact – between neighbouring cells– between a cell and the extracellular matrix or – control the paracellular transport.
Special types of EpitheliumSpecial types of Epithelium Pseudostratified columnar epithelium: It is a
type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia.
Keratinized Epithelium: – most apical layers (exterior) of cells are dead and lose
their nucleus and cytoplasm – contain a tough, resistant protein called keratin
Special types of EpitheliumSpecial types of Epithelium
Transitional Epithelium: – found in tissues that stretch– sometimes called the urothelium– almost exclusively found in the bladder,
ureters and urethra
Fig: Keratinized Squamous Epithelium
Muscle TissueMuscle Tissue
Muscle cells form the active contractile tissue of the body known as muscle tissue
Muscle tissue is separated into three distinct categories: – visceral or smooth muscle– skeletal muscle– cardiac muscle
Structure of muscle tissueStructure of muscle tissue
Stucture of smooth muscle Stucture of smooth muscle
Structure of Cardiac muscleStructure of Cardiac muscle
Nervous TissueNervous Tissue
Nervous tissue is the main component of the nervous system - the brain, spinal cord, and nerves-which regulates and controls body functions.
It is composed of neurons, which transmit impulses, and the neuroglia cells, which assist propagation of the nerve impulse and provide nutrients to the neuron.
Structure of a NeuronStructure of a Neuron
Methods of tissue diagnosisMethods of tissue diagnosis
Examination of tissues starts with surgery, biopsy, or autopsy
The tissue is removed from the body and then placed in a fixative which stabilizes the tissues to prevent decay
The most common fixative is formalin
What is a Biopsy?What is a Biopsy?
Biopsy is the removal of tissue for the purpose of diagnostic examination.
Principles and Techniques of Principles and Techniques of BiopsyBiopsy
It is important to develop a systematic approach in evaluating a patient with a lesion
These steps include :These steps include :
A detailed health historyA history of the specific lesionA clinical examinationA radiographic examinationLaboratory investigationsSurgical specimens for histopathologic
evaluation
Medical conditions that Medical conditions that warrant special care include:warrant special care include:CoagulopathiesHypertensionPoorly controlled diabetesImmunocompromised patients
History of the LesionHistory of the Lesion
Questions to AskQuestions to Ask
Duration of the lesionChanges in size and rate of changeChanges in the character of the lesion.
– Lump to ulcer, etcAssociated systemic symptoms:
– fever– nausea– anorexia
More Questions to AskMore Questions to AskPainAbnormal sensationsAnesthesiaA feeling of swellingBad taste or smell DysphagiaSwelling or tenderness of adjacent lymph
nodesCharacter of the pain if present
Clinical ExaminationClinical Examination
The clinical examination should always include when possible:– Inspection– Palpation– Percussion– Auscultation
Clinical EvaluationClinical Evaluation
The anatomic location of the lesion/mass The physical character of the lesion/mass The size and shape of the lesion/mass Single vs. multiple lesions The surface of the lesion The color of the lesion The sharpness of the boundaries of the lesion The consistency of the lesion to palpation Presence of pulsation Lymph node examination
Radiographic ExaminationRadiographic Examination The radiographic appearance may provide clues
that will help determine the nature of the lesion. A radiolucency with sharp borders will often be
a cyst A ragged radiolucency will often be a more
aggressive lesion Radiopaque dyes and instruments can help
differentiate normal anatomy
Indications for BiopsyIndications for Biopsy Any lesion that persists for more than 2 weeks
with no apparent etiologic basis Any inflammatory lesion that does not respond
to local treatment after 10 to 14 days. Persistent hyperkeratotic changes in surface
tissues. Any persistent tumescence (swelling) either
visible or palpable beneath relatively normal tissue.
Indications for BiopsyIndications for Biopsy Inflammatory changes of unknown cause that
persist for long periods Lesion that interfere with local function Bone lesions not specifically identified by
clinical and radiographic findings Any lesion that has the characteristics of
malignancy
Characteristics of lesions that raise the Characteristics of lesions that raise the suspicion of malignancysuspicion of malignancy
Erythroplasia- lesion is totally red or has a speckled red appearance.
Ulceration- lesion is ulcerated or presents as an ulcer. Duration- lesion has persisted for more than two weeks. Growth rate- lesion exhibits rapid growth Bleeding- lesion bleeds on gentle manipulation Induration- lesion and surrounding tissue is firm to the
touch Fixation- lesion feels attached to adjacent structures
Types of BiopsyTypes of Biopsy
Fine neeedle aspiration biopsy/cytology (FNAB or FNAC)
Tru-cut biopsyIncisional biopsy Excisional biopsyCone biopsyWedge biopsyFrozen section biopsy
Fine Needle Aspiration BiopsyFine Needle Aspiration Biopsy Aspiration biopsy is the use of a needle and syringe
to penetrate a lesion for aspiration of its contents. Indications:
– To determine the presense of fluid within a lesion– The type of fluid within a lesion– When exploration of an intraosseous lesion is
indicated
AspirationAspiration
An 18 gauge needle on a 5 or 10 ml syringe is inserted into the area under investigation after anesthesia is obtained.
The syringe is aspirated and the needle redirected if necessary to find the fluid cavity.
FNACFNAC
Tru-cut biopsyTru-cut biopsy
The tru-cut biopsy aims to provide the pathologist with a core of undamaged tissue from the lesion.
The procedure is performed using a specially designed needle known as the Trucut needle
PRINCIPLE OF TRUCUT BIOPSYPRINCIPLE OF TRUCUT BIOPSY
Incisional BiopsyIncisional Biopsy
An incisional biopsy is a biopsy that samples only a particular portion or representative part of a lesion.
If a lesion is large or has different characteristics in various locations more than one area may need to be sampled
Incisional BiopsyIncisional Biopsy Indications:
– Size limitations – Hazardous location of the lesion– Great suspicion of malignancy
Technique:– Representative areas are biopsied in a wedge fashion.– Margins should extend into normal tissue on the deep
surface.– Necrotic tissue should be avoided.– A narrow deep specimen is better than a broad shallow
one.
Incisional BiopsyIncisional Biopsy
Excisional BiopsyExcisional Biopsy
An excisional biposy implies the complete removal of the lesion.
Indications:– Should be employed with small lesions. Less than 1cm– The lesion on clinical exam appears benign.– When complete excision with a margin of normal tissue is
possible without mutilation.
Excisional BiopsyExcisional Biopsy
Technique:– The entire lesion with 2 to 3mm of normal
appearing tissue surrounding the lesion is excised if benign.
Wedge BiopsyWedge Biopsy
An excisional biopsy in which a lesion identified at the time of a surgical procedure is removed, with a wedge of normal surrounding tissue
Wedge BiopsyWedge Biopsy
Cone BiopsyCone Biopsy A cone biopsy is an extensive form of a cervical
biopsy It is called a cone biopsy because a cone-shaped
wedge of tissue is removed from the cervix and examined under a microscope
A small amount of normal tissue around the cone-shaped wedge of abnormal tissue is also removed so that a margin free of abnormal cells is left in the cervix.
Cervical Cone BiopsyCervical Cone Biopsy
Frozen Section BiopsyFrozen Section BiopsyThis technique allows examining histologic
sections within a few minutes of removing the specimen from the patient.
The quality of the tissue sections is not as good as those of the permanent section.
Commonly done intraoperatively for quick results.
Frozen Section BiopsyFrozen Section Biopsy
Technique: The tissue is frozen and sliced thinly using a microtome mounted in a below-freezing refrigeration device called the cryostat.
The thin frozen sections are mounted on a glass slide, fixed immediately in liquid fixative, stained and examined under microscope.
Biopsy guidanceBiopsy guidance
Blindly without any guidanceX-ray to see the locationUSG guidedCT guidedMRI guided
Principles of Surgery for Principles of Surgery for BiopsyBiopsy
AnesthesiaAnesthesia
Block anesthesia is preferred to infiltration
When blocks are not possible distant infiltration may be used
Never inject directly into the lesion
Tissue StabilizationTissue Stabilization
Digital stabilizationSpecialized retractors/forcepsRetraction suturesTowel Clips
HemostasisHemostasis
Gauze compresses are usually adequateSuction devices should be avoided
IncisionsIncisions Incisions should be made with a scalpel. They should be converging Should extend beyond the suspected depth of the lesion They should parallel important structures Margins should include 2 to 3mm of normal appearing
tissue if the lesion is thought to be benign. 5mm or more may be necessary with lesions that appear
malignant, vascular, pigmented, or have diffuse borders.
Handling of the Tissue Handling of the Tissue SpecimenSpecimenDirect handling of the lesion will expose
it to crush injury resulting in alteration the cellular architecture.
Specimen CareSpecimen Care
The specimen should be immediately placed in 10% formalin solution, and be completely immersed.
Margins of the BiopsyMargins of the Biopsy
Margins of the tissue should be identified to orient the pathologist. A silk suture is often adequate.
Biopsy Data SheetBiopsy Data Sheet
A biopsy data sheet should be completed and the specimen immediately labeled.
All pertinent history and descriptions of the lesion must be conveyed.
Conditions identified with biopsyConditions identified with biopsy
CancerPrecancerous conditions Inflammatory conditionsInfections e.g. TuberculosisAutoimmune disorders e.g. lupus
Biopsy ResultsBiopsy Results
A biopsy is most commonly done to indentify malignancy
Characteristics of Benign and Characteristics of Benign and Malignant neoplasmsMalignant neoplasms
In the great majority of instances, the differentiation of a benign from a malignant tumor can be made morphologically with considerable certainty
There are criteria by which benign and malignant tumors can be differentiated
Characteristics of Benign and Characteristics of Benign and Malignant neoplasmsMalignant neoplasms
These differences can be discussed under the following headings:
(1) Differentiation and anaplasia(2) Rate of growth: Most malignant tumours
are rapidly growing(3) Local invasion: Malignant tumours may be
locally invasive (4) Metastasis: Occurs in malignant tumours
DIFFERENTIATION AND ANAPLASIADIFFERENTIATION AND ANAPLASIA
Differentiation: Differentiation refers to the extent to which parenchymal cells resemble comparable normal cells, both morphologically and functionally– Well-differentiated tumors are thus composed of
cells resembling the mature normal cells of the tissue of origin of the neoplasm
– Poorly differentiated or undifferentiated tumors have primitive-appearing, unspecialized cells
DIFFERENTIATION AND ANAPLASIADIFFERENTIATION AND ANAPLASIA
Anaplasia: Malignant neoplasms composed of undifferentiated cells are said to be anaplastic
Indeed, lack of differentiation, or anaplasia, is considered a hallmark of malignant transformation
Microscopic features of malignancyMicroscopic features of malignancy
Loss of normal tissue architecture Increased mitotic rate: Mitoses are rarely seen in
normal tissues. Malignant cells will often have increased numbers of mitoses
Pleomorphism: Malignant cells may show a range of shapes and sizes, in contrast to regularly sized normal cells. The nuclei of malignant cells are often very large and may contain prominent nucleioli
Microscopic features of Microscopic features of malignancymalignancy Hyperchromatic nuclei: The nuclei of malignant
cells typically stain a much darker colour than their normal counterparts
High nuclear-cytoplasmic ratio: The nuclei of malignant cells often take up a large part of the cell compared with normal cell nuclei
Giant cells: Some malignant cells may coalesce into so-called giant cells, which might contain the genetic material of several smaller cells.
Microscopic features of Microscopic features of malignancymalignancyAngiogenesis - malignant tumours must
form new blood vessels in order to expand locally. Angiogenesis is also important for metastasis.
Normal Vs Malignant tissueNormal Vs Malignant tissue
Normal Vs Malignant tissueNormal Vs Malignant tissue
Normal Vs Malignant CellsNormal Vs Malignant Cells
A. Normal Papanicolaou smear from the uterine cervix. Large, flat cells with small nuclei. B, Abnormal smear containing a sheet of malignant cells with large hyperchromatic nuclei. There is nuclear pleomorphism, and one cell is in mitosis
Tumour giant cellTumour giant cell
Malignant cells with an osteoclast-type giant cell
Malignant Epithelpoid CellsMalignant Epithelpoid Cells
Immunohistochemical staining : (a) Normal (non-neoplastic) breast tissue; Note staining in normal ducts. (b) Human breast carcinoma (infiltrating ductal carcinoma); formalin-fixed, paraffin-embedded tissue. Note strong membranous staining in breast cancer. (c) Normal (non-neoplastic) breast tissue; frozen tissue. Note staining in normal ducts. (d) Human breast carcinoma; frozen tissue. Note staining of invasive breast carcinoma.
Biopsy Results: What If ?Biopsy Results: What If ? They don’t corroborate your clinical impression
– Repeat the biopsy– Determine if the tissue was looked at by an
experienced Pathologist