Tissue diagnosis involves examining tissues through biopsy to identify conditions such as cancer, infections, and inflammatory disorders. There are four main types of tissue - connective, epithelial, muscle and nervous. Biopsies are usually done using fine needle aspiration, core needle biopsy, or excisional biopsy. The tissue is examined under a microscope to look for features of malignancy like abnormal growth, invasion of surrounding areas, and metastasis. Tissue diagnosis is an important tool for medical diagnosis and treatment planning.

1. Principles of Tissue Diagnosis

2. Presented by-
Dr. Fariha Hussain
Intern Doctor
Surgery Unit- 5
ShSMCH

3. Definition 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

4. Prokaryote Vs Eukaryote

5. Definition 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

6. Four types of tissue

7. Connective Tissue
 Connective tissue is a fibrous tissue.
 It is the most diverse tissue and found
throughout the body
 Has 3 main components: Cells, Fibers,
and Extracellular matrix

8. Connective 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

9. Connective Tissue

10. Functions of connective tissue
 Providing structural framework for the
body
 Connection of body tissues
 Storage of energy
 Protection of organs

11. Epithelial Tissue
Epithelial tissues line the cavities and
surfaces of structures throughout the
body, and also form many glands.

12. Structure 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

13. Structure 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.

15. Special 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

16. Special types of Epithelium
 Transitional Epithelium:
– found in tissues that stretch
– sometimes called the urothelium
– almost exclusively found in the bladder,
ureters and urethra

18. Fig: Keratinized Squamous Epithelium

20. Muscle 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

21. Structure of muscle tissue

22. Stucture of smooth muscle

23. Structure of Cardiac muscle

24. Nervous 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.

25. Structure of a Neuron

26. Methods 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

27. What is a Biopsy?
 Biopsy
is the removal of tissue for the
purpose of diagnostic examination.

28. Principles and Techniques of
Biopsy
 It is important to develop a systematic
approach in evaluating a patient with a
lesion

29. These steps include :
A detailed health history
 A history of the specific lesion
 A clinical examination
 A radiographic examination
 Laboratory investigations
 Surgical specimens for histopathologic
evaluation

30. Medical conditions that
warrant special care include:
 Coagulopathies
 Hypertension
 Poorly
controlled diabetes
 Immunocompromised patients

31. History of the Lesion

32. Questions to Ask
 Duration of the lesion
 Changes in size and rate of change
 Changes in the character of the lesion.
– Lump to ulcer, etc
 Associated systemic symptoms:
– fever
– nausea
– anorexia

33. More Questions to Ask
 Pain
 Abnormal sensations
 Anesthesia
A feeling of swelling
 Bad taste or smell
 Dysphagia
 Swelling or tenderness of adjacent lymph
nodes
 Character of the pain if present

34. Clinical Examination
 The clinical examination should always
include when possible:
– Inspection
– Palpation
– Percussion
– Auscultation

35. Clinical 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

36. Radiographic 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

37. Indications 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.

38. Indications 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

39. Characteristics of lesions that raise the
suspicion 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

40. Types of Biopsy
 Fine neeedle aspiration biopsy/cytology
(FNAB or FNAC)
 Tru-cut biopsy
 Incisional biopsy
 Excisional biopsy
 Cone biopsy
 Wedge biopsy
 Frozen section biopsy

41. Fine 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

42. Aspiration
 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.

43. FNAC

44. Tru-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

45. PRINCIPLE OF TRUCUT BIOPSY

46. Incisional 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

47. Incisional 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.

48. Incisional Biopsy

49. Excisional 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.

50. Excisional Biopsy
 Technique:
– The entire lesion with 2 to 3mm of normal
appearing tissue surrounding the lesion is excised
if benign.

51. Wedge Biopsy
 Anexcisional biopsy in which a lesion
identified at the time of a surgical
procedure is removed, with a wedge of
normal surrounding tissue

52. Wedge Biopsy

53. Cone 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.

54. Cervical Cone Biopsy

55. Frozen Section Biopsy
 This 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.

56. Frozen 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.

57. Biopsy guidance
 Blindly without any guidance
 X-ray to see the location
 USG guided
 CT guided
 MRI guided

58. Principles of Surgery for
Biopsy

59. Anesthesia
 Block anesthesia is preferred to
infiltration
 When blocks are not possible distant
infiltration may be used
 Never inject directly into the lesion

60. Tissue Stabilization
 Digitalstabilization
 Specialized retractors/forceps
 Retraction sutures
 Towel Clips

61. Hemostasis
 Gauze compresses are usually adequate
 Suction devices should be avoided

62. Incisions
 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.

63. Handling of the Tissue
Specimen
 Direct handling of the lesion will expose
it to crush injury resulting in alteration
the cellular architecture.

64. Specimen Care
 Thespecimen should be immediately
placed in 10% formalin solution, and be
completely immersed.

65. Margins of the Biopsy
 Margins of the tissue should be identified
to orient the pathologist. A silk suture is
often adequate.

66. Biopsy 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.

67. Conditions identified with biopsy
 Cancer
 Precancerous conditions
 Inflammatory conditions
 Infections e.g. Tuberculosis
 Autoimmune disorders e.g. lupus

68. Biopsy Results
A biopsy is most commonly done to
indentify malignancy

69. Characteristics of Benign and
Malignant 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

70. Characteristics of Benign and
Malignant 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

71. DIFFERENTIATION 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

72. DIFFERENTIATION 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

73. Microscopic 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

74. Microscopic features of
malignancy
 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.

75. Microscopic features of
malignancy
 Angiogenesis - malignant tumours must
form new blood vessels in order to expand
locally. Angiogenesis is also important for
metastasis.

76. Normal Vs Malignant tissue

77. Normal Vs Malignant tissue

78. Normal 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

79. Tumour giant cell
Malignant cells with an osteoclast-type giant cell

80. Malignant Epithelpoid Cells

81. 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.

82. 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