This document provides an overview of fine needle aspiration cytology (FNAC). It discusses the history, advantages, limitations, equipment, techniques, processing, complications, and applications of FNAC for diagnosing lesions in the salivary gland, oral cavity, and other areas. FNAC is a simple, economical technique that can provide a rapid diagnosis without the need for an open biopsy. It describes the evaluation of FNAC samples under the microscope for diagnosing various conditions.

1. Fine Needle Aspiration
Cytology
Presented by:
Dr Kalpajyoti
Bhattacharjee

2. CONTENTS
 INTRODUCTION
 HISTORICAL PERSPECTIVE
 ADVANTAGE
 LIMITATIONS
 EQUIPMENTS
 FINE NEEDLE ASPIRATION TECHNIQUE
 PROCESSING
 FIXATION & STAINING
 COMPLICATIONS
 FNAC IN SALIVARY GLAND, ORAL CAVITY.

3. INTRODUCTION
 Fine Needle Aspiration Cytology (FNAC) is a
technique whereby cells are obtained from a
lesion using a thin bore needle and smears
are made for cytopathological diagnosis.
 This technique is based on the fact that tumor
cells are less cohesive and are easily
aspirated.
 Used in the diagnosis of breast lumps, thyroid
nodules, liver disease, subcutaneous soft
tissue mass, salivary gland diseases and oral
diseases.

4.  Oral cavity is a site where mucosa is very vascular and an
open biopsy leads to a lot of bleeding which is difficult to
control.
 In recent times FNAC solves these problems, adequate
material can easily be obtained by using a 10 ml. syringe
from an intraoral or extraoral site without any discomfort to
the patient and with no bleeding.
 In some cases a subsequent surgery is not needed and
patient can be put on appropriate treatment.
 FNAC report is prepared within 24 hours of sampling gives
early, quick information to the surgeon about the type of
lesion he is dealing with.

5. HISTORICAL PERSPECTIVE
 The technique was introduced in the 1930s by Martin
and Ellis in the United States, but it never became
widespread.
 Since the 1950s it has been used extensively in
Scandinavia and in Holland.
 Fine Needle for aspiration were first introduced in
Europe in the 1950’s by Lopez-Cardozo in the
Netherlands and Soderstrom in Sweden
 Publication by Zajicek from Karolinska Hospital in
Stockholm that brought aspiration cytology to
international alterations.

6. ADVANTAGE
 Simple office technique
 Rapid diagnosis
 Economical
 Sampling from multiple sites in the same sitting
 High diagnostic accuracy
 Many techniques such as bacterial culture,
immunocytochemistry, flow cytometry, cytogenetics,
polymerase chain reaction, etc. are possible from
FNAC material.

7. LIMITATIONS
 Loss of tissue architecture
 Capsular invasion and lymphovascular invasions
cannot be detected
 Difficult to differentiate in situ versus invasive
carcinoma
 Considerable training is needed for accurate
interpretation.

8. FNAC AS A TOOL IN CLINICAL
INVESTIGATION
 Initially used as a mean to confirm a clinical suspicion
of local recurrence or metastasis of known cancer
without subjecting the patient to further surgical
intervention.
 Inflammation, infection, degenerative conditions, in
diagnosis and monitoring of graft rejection in
transplantation surgery
 Alternative or complement to frozen section
 Intraoperative cytology

9. THE PRACTICE OF FNAC
 Success of FNAC depends on four fundamental
requirement:
1. Samples must be representative of the lesion
investigated.
2. Samples must be adequate in terms of cells & other
tissue components
3. Samples must be correctly smeared and processed
4. Biopsy must be accompanied by relevant and
correct clinical/radiological information.

10. EQUIPMENTS
1. NEEDLES: Routinely 22-23 gauge needle used.
2. Syringes: 20 ml syringe
3. Pistol handle

11. 4) Sterile container: Physiological saline or Hank’s
balanced solution
5) Slides: clean, dry & free of grease.
6) A 0.4 mm haemocytometer coverslip gives better
control over smearing pressure & a more perfect
spread
7) Fixatives: 70-90% ethanol, Carnoy’s fixative, 10%
buffered formalin, gluteraldehyde used
8) Stains
9) Microscopes

12. FINE NEEDLE ASPIRATION TECHNIQUE
 2 techniques:
1. FNAC with aspiration
2. FNAC without aspiration

13. Site of FNAC should be
cleaned by spirit swab
Needle is introduced in the swelling and is gently
moving to and fro. Simultaneously negative suction
is also created by withdrawing the piston
Air is taken in the syringe and needle is reattachedThe aspirated material is expelled and the
smear is made by gently pressing the upper
slide on the lower one
FNAC with aspiration

15. -Introduced by Zajdela in 1987
-based on the observation that the capillary pressure in a
fine needle is sufficient to keep the detached cell inside the
lumen of the needle
FNAC without aspiration

16. FAILURE TO OBTAIN A REPRESENTATIVE
SAMPLE
 Needle has missed the target tangentially
 Needle in central cystic/necrotic/hemorrhagic area
devoid of diagnostic cells.
 Needle in dominant benign mass missing a small
adjacent malignant lesions.
 Fibrotic/desmoplastic target tissue giving a scant cell
yield.

18. PROCESSING THE SAMPLE
Sample expelled on to a clean & dry
microscope slide using air in a syringe.
SMEARING
DIRECT
INDIRECT

19. DIRECT
SMEARING
DRY
Creamy consistency &
consists of numerous
cells suspended in a
small amount of tissue
fluid
WET
Smaller number of cells
suspended in fluid or
blood

20.  Indirect smearing: Thin fluid samples are
best processed by centrifugation on the
cytocentrifuge.
 Milipore nucleopore filtration is an alternative
 Thinprep technique

21. FIXATION & STAINING
 2 fundamentally different methods of fixation &
staining are used in FNAC:
1. Air drying followed by staining with a
haematological stain such as MAY GRUNWALD-
GIEMSA STAIN , Jenner-Giesma, Diff-Quik
2. Alcohol fixation and staining according to PAP or
with H&E.

22. Papanicolaou stain
Contents:
 Harris’s hematoxylin
 Orange G6
 EA 50
Results:
 Nuclei- blue/black
 Cytoplasm (non-keratinizing)- blue/green
 Keratinizing cells- pink/orange

23. Romanowsky stain
Contents:
 Methylene blue/azure B and eosin, dissoved in
acetone-free methanol, include jenner, Giesma, May
Grunwald and Leishman stain
Results:
 Nuclei- purple/blue
 Cytoplasm- pink/blue
 Eosinophils- pink/red

24.  Diff-Quik is a commercial Romanowsky stain variant,
commonly used in histological staining to rapidly stain and
differentiate a variety of smears, commonly blood and non-
gynecological smears, including those of fine needle
aspirates.

25. MAY GRUNWALD- GIEMSA STAIN
 commonly used staining of blood smears
Contents:
 methylene blue (a basic dye)
 Azures (also basic dyes)
 Eosin (an acid dye)
Results:
 Nuclei of white blood cells and the granules of
basophil granulocytes- blue
 Red blood cells and eosinophil granules – red
 cytoplasm of white blood cells - light blue

26. SPECIAL STAINS
1. PAS or Alcian blue - mucins, glycogen
2. Prussian blue - iron
3. Masson-Fontana - melanin
4. Congo red - amyloid
5. Ziehl-neelson - acid fast bacilli
6. Bile pigment- Fauchet’s reagent counterstained with
sirus red.
7. Gram, PAS or Gomori’s silver stain for microorganism

27. COMPLICATIONS
 Usually free of complications
 Bleedings, hematoma, emphysema (in lung).
 Rarely anaphylactic reaction- accidental
rupture of hydrated cyst

28. FNAC OF SALIVARY GLAND
 FNAC of the salivary gland lesions has gained wide
clinical recognition.
 The incisional biopsy of the salivary gland may cause
fistula formation and other complications that can be
avoided in FNAC.
 For accurate diagnosis of salivary gland lesions, an
adequate sample stained by both May Grunwald-
Giemsa stain and Papanicolaou’s stain (or H and E)
along with detailed clinical history are needed.

29. Cytology of Normal Salivary Glands
Benign ductal cells: These cells are usually in
small clusters or monolayered sheets. The cells
are round to oval, with scanty cytoplasm having
monomorphic nuclei.
Acinar cells: These are commonly present as
small ball like clusters. The individual cells are
round with abundant foamy cytoplasm and small
round nuclei. The acinar cells may also be present
discretely and cells with bare nuclei may be
mistaken as lymphocytes.

30. Myoepithelial cells: These are oval to
spindle shaped cells present near the
basement membrane of the ductules. Oval
plasmacytoid myoepithelial cells may also be
seen.
Fibrous tissue: Fragments of fibrous and
adipose tissue may also be seen in the
background of the normal salivary aspirate.

31. Aspirate of normal salivary gland tissue showing
grapelike clusters of epithelial cells composed of spherical
acini and branching ducts (Romanowsky’s stain).

32. Benign acinar cells arranged in ‘‘rosette’’ formation. The cells have
abundant foamy vacuolated cytoplasm with indistinct cell borders, and
eccentric nuclei (Papanicolaou stain).

33. Diagnostic approach of salivary gland tumors

34. Fatty Infiltration
 Presents as a diffuse enlargement
 Addition to normal salivary gland elements, there is
significant increase in the amount of adipose tissue
situated between ductal and acinar cells
 Associated with diabetes, cirrhosis, alcoholism,
medications, nutritional deficiencies and hormonal
disturbances

35. Chronic sialadenitis
 Commonly results from stones or postsurgical scarring
 More frequently seen in the submandibular gland
Cytology:
 low cellularity and show predominance of ductal cells,
background has variable number of lymphocytes,
occasional plasma cells and neutrophils, and spindle
fibroblasts
 Squamous and mucinous metaplasia may be focally
encountered
 Acute sialadenitis: seldom sampled, many neutrophils
are admixed with benign salivary gland elements, reactive
and reparative changes may be seen

36. Short tubular segments of ductal epithelium composed of small hyperchromatic
cells characteristic of chronic sialadenitis
(Romanowsky’s stain).

37. Benign Lymphoepithelial Cysts of the Parotid
Glands
Cytology:
 Smears - characterized by a mixed lymphoid infiltrate
with a predominance of small mature lymphocytes
 Characteristically has a watery proteinaceous
background in which the lymphoid elements are
distributed
 Cuboidal or mucin-containing cells may be found
distributed singly in the smear

38. Aspirates of benign lymphoepithelial cysts are characterized by a
mixed population of lymphoid cells dispersed in a watery
background (Romanowsky’s stain).

39. Pleomorphic Adenoma
 Pleomorphic adenoma (PA) commonly involves the parotid
gland (more than 75%).
 painless, slow growing, firm to hard swelling of the salivary
gland.
Cytology
• Pinkish fibrillar chondromyxoid matrix material with frayed
indistinct margins
• Clusters of round, ovoid or plasmacytoid epithelial cells with
moderate amount of dense cytoplasm
• Clusters and discrete spindle shaped myoepithelial cells
embedded in mesenchymal stroma

40. Immunochemistry:
Epithelial cells are positive for cytokeratin (CK)
Myoepithelial cells are positive for CK and vimentin
(co-expressed), S-100, Glial fibrillary acid protein
(GFAP) and Calponin

41. Long strands of spindle cells
embedded in the connective tissue
stroma
(H & E)
Cellular pleomorphic adenoma
showing discrete and cluster of
epithelial cells
(H & E)

42. Clusters of epithelial and myoepithelial
cells associated with fragments of
myxoid and chondroid stroma are
characteristic of pleomorphic
adenomas
(Papanicolaou’s stain)
The myxoid-chondroid stroma
of pleomorphic adenomas often
has a fibrillary character along
its edges (Romanowsky’s stain)
The myoepithelial cell
component of pleomorphic
adenomas
frequently has a plasmacytoid
appearance
(Romanowsky’s stain)

43. Warthin’s Tumor
 2nd most common tumor, occurs almost exclusively in
parotid gland.
Cytology:
 The aspirate has a thin watery mucoid appearance,
and consists of a mixed population of lymphocytes,
occasional plasma cells, and variable number of
oncocytes
 mucoid material or greenish-brown dirty fluid
 Many cohesive sheets of oncocytes
 Squamous and mucinous metaplasia.

44. There is admixed population of large
flat sheets of oncocytes and lymphoid
cells.
The epithelial cells have abundant
dense eosinophilic cytoplasm, well
defined cytoplasmic border, enlarged
centrally placed nuclei, and prominent
nucleoli (Papanicolaou stain)
Aspirates of Warthin tumors are
characterized by a mixed population
of lymphocytes and clusters of
epithelial cells with abundant
granular cytoplasm. The cells lie
within a dirty proteinaceous
background
(Romanowsky’s stain).

45. Basal Cell Adenoma (BCA)
 Basal cell adenoma (BCA) is an uncommon salivary
gland tumor
 The majority of BCA arises in the major salivary gland.
 The parotid gland is the predominant site of
occurrence and more than 75 percent of BCA arise in
parotid gland.

46. Cytology:
 Cohesive groups of basaoid cells
 Peripheral palisading arrangement
 Round nucleus, bland nuclear chromatin and scanty
cytoplasm
 Squamous morules
 Scanty homogeneous acellular stromal material.

47. Tightly cohesive clusters of basaloid
cells and many background stripped
nuclei
(DQ stain)
Membranous variant of basal cell
adenoma. There is dense hyaline
extracellular material surrounding the
basaloid cell clusters. (Papanicolaou stain)

48. Oncocytoma
 This is a benign salivary gland neoplasm that
predominantly involves parotid gland (about 75%).
 The tumor predominantly presents as a painless
mobile mass.
 Occurs exclusively among elderly people
 Pain is generally absent.

49. Cytology:
 Three-dimensional clusters of oncocytes
 Polygonal cells with abundant densely granular
eosinophilic cytoplasm
 Central to eccentric monomorphic round nucleus.

50. Predominantly discrete oncocytic
cells in FNAC smear
(MGG)
Oncocytomas contain epithelial
cells with abundant granular
cytoplasm identical to those seen
in Warthin tumors, but
oncocytomas lack the lymphoid
component
(Romanowsky’s stain).

51. Myoepithelial Tumors
 This tumor comprises only 11.5 percent of all salivary
gland neoplasms.
 The patient usually presents as a slow growing
painless mass in the parotid or minor salivary gland
regions.

52. Cytology:
Spindle cell type
• Abundant clusters and dissociated spindle cells
• Elongated nuclei, fine nuclear chromatin and
inconspicuous nucleoli
Hyaline myoepithelial cells
• Dissociated round to oval cells
• Plasmacytoid cells with abundant cytoplasm and
eccentric nucleus.

53. The hyaline variant of myoepithelioma showing dissociated
plasmacytoid cells with abundant cytoplasm and eccentric
nucleus
(MGG)

54. Adenoid cystic carcinoma
 Adenoid cystic carcinoma (ACC) is a slow growing
tumor.
 Tendency to recurrence
 ACC infiltrates local nerves, causes paralysis of the
motor nerves and produces pain in the ear.
 Most common in parotid

55. Cytology:
• Multiple variable sized globular, spherical or tubular
homogeneous, acellular magenta colored matrix
material
• These globules are surrounded by cells
• Clusters and dissociated small cells with scanty
cytoplasm
• Round monomorphic hyperchromatic nuclei with
coarse chromatin.
IHC:
High Ki67 index.
c-Kit overexpression noted.

56. Small round cells with scanty
cytoplasm along with pinkish hyaline
globules
(MGG)
Cells arranged around the pinkish
globules
(MGG)

57. Adenoid cystic carcinoma.
The neoplastic cells have oval to round hyperchromatic nuclei with finely to
coarsely granular chromatin and scant cytoplasm.
They are associated with hyaline globules, which stain pale gray-green in this
preparation.
(Papanicolaou stain)

58. Acinic Cell Carcinoma
 Malignant epithelial neoplasm of the duct apparatus,
but occasional lesions seem to show acinar
differentiation
Cytology:
 low-grade malignancy characterized by sheets of
large cells with abundant cytoplasm
 The neoplastic cells have foamy/vacuolated
cytoplasm with ill-defined borders, eccentrically placed
nuclei, small inconspicuous nucleoli, and lack
significant nuclear atypia or pleomorphism
 Occasionally lymphocytes and psammoma bodies
 Clean background.

59. A, Acinic cell carcinomas are characterized cytologically by irregular clusters and sheets
of epithelial cells with foamy or granular cytoplasm and bland nuclei (Romanowsky’s
stain).
B, Some cells of acinic cell carcinomas contain characteristic red granules within their
cytoplasm (Romanowsky’s stain).
C, Cells from acinic cell carcinomas have a finely vacuolated or foamy cytoplasm
(Romanowsky’s stain).

60. Mucoepidermoid Carcinoma
 Mucoepidermoid carcinoma (MEC) originates from the
ductal cells of the salivary gland and is commonly
located in the parotid gland.
 Low-grade MEC is commonly cystic and is
cytologically characterized by an admixture of
glandular and metaplastic squamous cells.
 The background demonstrates mucinous material and
debris
 The glandular cells may have a ductal appearance
(intermediate cells) or may resemble macrophages
(mucin-producing cells)

61.  High-grade MEC has a less prominent cystic
component and greater degree of atypia, compared
with low-grade MEC.
 High-grade MEC is cytologically characterized by
large pleomorphic cells with predominantly epidermoid
or undifferentiated cell features
 Glandular cells are rarely seen in high-grade MEC,
but their presence in association with squamous cells
establishes the diagnosis.

62. Abundant dissociated squamoid
cells with nuclear enlargement and
pleomorphism. Occasional mucus
secreting cells are also seen
(H & E)
High-grade mucoepidermoid
carcinoma. The cells are large,
pleomorphic and show severe
cytologic atypia. The cytoplasm has a
dense quality with squamoid features
(Papanicolaou stain)

63. Salivary Duct Carcinoma
 Salivary duct carcinoma (SDC) is a rare primary salivary
gland malignancy, high and low grades.
 High-grade SDC is the most common subtype (>90% of
cases) and considered one of the most aggressive salivary
gland malignancies.
 Moderate to severe nuclear atypia and pleomorphism,
presence of associated necrosis in the background
constitutes an important clue to the diagnosis of high-grade
SDC.
 In low-grade SDC, the neoplastic cells have a uniform
appearance and show minimal atypia

64. High-grade salivary duct carcinoma. There are flat sheets of epithelial cells with
abundant delicate cytoplasm and moderate nuclear atypia.
The nuclei are round to oval in shape and show finely granular chromatin and
prominent nucleoli. Abundant necrosis is associated with the malignant cells
(Papanicolaou stain)

65. Epithelial-myoepithelial carcinoma
 Epithelialmyoepithelial carcinoma (EMC) is regarded
as a low to intermediate-grade malignancy with
propensity for local recurrence
 FNA is usually of high cellularity and shows two
distinct cell populations, ductal and myoepithelial

66. Epithelial-myoepithelial carcinoma. Dual populations of ductal and myoepithelial
cells.
The ductal cells are more cohesive, three-dimensional, and show less amount of
cytoplasm. The myoepithelial cells are arranged as loosely cohesive groups of
large cells with pale vacuolated (clear) cytoplasm and have round-elongated
nuclei and small nucleoli (Papanicolaou stain)

67. Polymorphous Low Grade Adenocarcinoma
 Polymorphous low grade adenocarcinoma (PLGA)
arises exclusively in the minor salivary glands and 60
percent of the tumor arises from the palate.
 The patient usually presents as painless mass in the
palate.
 Infiltrative growth and perineural invasion seen.

68. Cytology:
 Clusters and papillary arrangement of cells
 Small round to oval cells with scanty to moderate
cytoplasm
 Round nucleus, fine stippled nuclear chromatin and
inconspicuous nucleoli
 Magenta colored matrix material.

69. Cells are in tight cluster with scanty to moderate cytoplasm
(H & E)

70. FNAC OF ORAL CAVITY

71. Hemangioma
Cytology:
 Aspirates of hemangiomas are characterized by a
highly bloody background in which are dispersed
single, plump, spindle shaped cells and clusters of
spindle-shaped to ovoid cells
 most aspirates from hemangiomas are of scant
cellularity
 The aspirated tissue fragments often show a three-
dimensional “arcade” architecture with preserved
lumen
 The nuclei often run in a streaming pattern or may
form complex coils or tubular structures

72. Aspirates from hemangiomas have a bloody background in
which are scattered a small number of clusters of spindle cells.
These clusters may have a tubular appearance. The nuclei are
bland and elongated (Romanowsky’s stain)

73. Lipoma
Cytology:
 Aspirates of lipomas grossly yield an oily fluid that,
when smeared, has a glistening appearance.
 Microscopically lipomas are characterized by lacelike
sheets of adipose tissue.
 Free fat may be seen in the background and is
especially prominent in air-dried material.
 The tissue fragments have a three-dimensional
character and are composed of large adipocytes with
abundant clear cytoplasm and small round to ovoid
nuclei

74. Lipomas are characterized cytologically by tissue fragments with a
lacelike appearance. The individual cells have abundant clear
cytoplasm and small dark nuclei
(hematoxylin and eosin stain).

75. Granular Cell Tumor
Cytology:
 cellular with a background of granular debris
 Cells lie both singly and in syncytial groups.
 The cytoplasmic borders are indistinct, and the
cytoplasmic membranes frequently rupture, resulting
in scattered naked nuclei
 Within the syncytial aggregates, the nuclei may form a
pseudofollicular pattern or present as flat sheets of
cells.

76. Aspirates from granular cell tumors are characterized by syncytial groups
of cells with abundant granular cytoplasm surrounding bland round to
oval nuclei. The background of the smear has a dirty granular
appearance
(Papanicolaou’s stain).

77. intraoral Cysts and Tumors
 Odontogenic cysts, both developmental and
inflammatory types, share an essentially identical
cytomorphology.
 Aspirates contain abundant anucleated squamous
cells similar in appearance to superficial and
intermediate cells of stratified squamous epithelium
 Occasional odontogenic keratocysts will show
evidence of mineralization within the squamous cells
Odontogenic Cysts, Including Dentigerous Cysts,
Eruption Cysts, Odontogenic Keratocysts, and
Periapical Cysts

78.  The cytoplasm of the squamous cells is abundant and
brightly eosinophilic on Papanicolaou staining
 The cells often have a glassy refractile appearance
 The nuclei are round or slightly ovoid and centrally
located and possess a granular chromatin
 Occasional aggregates of keratinized eosinophilic bodies
are seen consistent with squamous pearls
 Developmental cysts usually contain little inflammation,
whereas inflammatory cysts contain prominent infiltrates
of neutrophils and histiocytes.

79. Ameloblastomas
Cytology:
 moderately cellular and composed of two types of
epithelial cells.
 The basaloid or ameloblast-like cells and the squamous
epithelial cells are present in varying proportions
 Basaloid cells - homogeneous and arranged in tight
clusters with well-defined edges, cells show nuclear
palisading
 The palisading cells have basophilic cytoplasm with poorly
defined cytoplasmic outlines, nuclei are round to oval

80.  Squamous epithelial cells - loosely cohesive and
demonstrates a dense glassy cytoplasm.
 The aggregates of squamous cells may contain spherical
keratinized bodies, round or oval nuclei that are centrally
placed, presence of spherical keratinized bodies in the
squamous cells is a common feature in ameloblastomas
 Foamy macrophages present

81. Ameloblastoma: Tight cluster of basaloid cells along with loose connective
tissue stroma
(H & E)

82. Schwannoma (Neurilemmoma)
Cytology:
 Generally hypocellular, with the majority of cells forming
small- to moderate-size tissue aggregates
 These tissue aggregates have a filamentous
appearance and indistinct cytoplasmic membranes
 low-power examination- the tissue clusters often have a
jigsaw puzzle appearance
 High-power examination- reveals these tissue clusters to
be composed of spindle-shaped cells with filamentous
cytoplasm
 Indistinct nuclear palisading is seen, but the cytologic
demonstration of Verocay bodies is rare

83. Aspirates from schwannoma contain tissue aggregates with
indistinct cytoplasmic membranes (Romanowsky’s stain).
Schwannomas contain spindle cells with filamentous cytoplasm
(inset). Nuclei are blunt or pointed with nuclear bends
(Romanowsky’s stain).

84. Calcifying Odontogenic Cysts
Cytology:
 Smears - moderate cellularity.
 Cells have a basaloid appearance with scant cytoplasm.
 A high proportion of the tissue fragments contain a
population of ghost cells characterized by densely
eosinophilic, homogeneous, glassy cytoplasmic structures
 Scattered MGCs, calcific debris, and ribbonlike fragments
of dense acellular material are scattered in the background
visible nuclei

85. Cementifying Fibroma
Cytology:
 Smears - cellular and contain single cells or clusters of
ovoid to spindle-shaped fibroblast-like cells, associated
with a large number of spherical calcified psammoma
bodies
 The cytoplasm of the spindle cells is scant with poorly
defined cell borders
 Presence of numerous spherical calcified psammoma
body–like structures admixed with a predominantly
fibroblastic population of cells should suggest a diagnosis
of benign fibro-osseous lesion

86. Odontogenic Myxoma
Cytology:
 Smear- yields abundant glistening viscous material that is
sparsely cellular
 Romanowsky stained, air-dried preparations show abundant
red-purple extracellular matrix with a granular or fibrillary
appearance
 Scattered within this matrix are a small number of plump
ovoid cells of uniform appearance, have moderate to
abundant pale blue cytoplasm that may be finely vacuolated
in some cases, nuclei are round to oval with a finely granular
chromatin
 No epithelial component is identified

87. Squamous Cell Carcinoma
 Most common oral cancer
Cytology:
 Divided into keratinizing and nonkeratinizing types
 Keratinizing squamous cell carcinoma- predominant single
cell presentation, single cells and clusters of neoplastic cells
are present.
 Keratinized malignant cell: cytoplasm refractile and
eosinophilic (PAP, H&E), dense blue (MGG)
 Perinuclear halo seen, irregular angular, densely
hyperchromatic nuclei.
 Squamous pearls are often seen
 Necrosis

88.  Non keratinising squamous cell carcinoma-
 Irregular solid cohesive fragments
 Elongated or spindle shaped nuclei
 Variable chromatin density in adjacent cells

89. Well differentiated kertinizing
squamous cell carcinoma: Smears
are characterized by high cellularity
with abundant anucleated and
nucleated keratinized squamous
cells.
(DQ stain)
Poorly differentiated squamous
cell carcinoma.
Smears show cohesive and
dyscohesive group of cells with
vesicular nuclei, coarsely granular
chromatin, and large prominent
nucleoli. No evidence of
squamous keratinization is seen in
the specimen
(Papanicolaou stain)

90. Melanoma
Cytology:
 Smear: highly cellular and characterized by marked
pleomorphism, most cells lie in a dyscohesive pattern
 Characterized by a mixture of epithelioid cells and smaller
numbers of malignant giant cells containing multiple
pleomorphic nuclei.
 Background rich in red blood cells, but a prominent tumor
diathesis with granular debris is frequent
 Romanowsky stain- deep, dark blue to nearly black pigment
 Papanicolaou staining- dark brown finely granular pigment.

91. Melanomas are characterized by dyscohesive spindle or epithelioid cells with
prominent nucleoli (Papanicolaou’s stain).
Melanin pigment may be seen in melanoma (hematoxylin and eosin stain).

92. Kaposi Sarcoma
Cytology:
 Usually hemorrhagic and contain scant tissue
fragments.
 The individual tissue fragments are of small to moderate
size.
 The larger tissue aggregates may display ill-defined
vascular spaces and a radial or parallel arrangement of
the elongated spindle-shaped cells
 Individual cells are represented by naked nuclei with
loss of cytoplasm.
 Fragments of pink- mauve stroma may be found in the
background.

93. Kaposi sarcoma contains radial arrangements of elongated
spindle cells
(Romanowsky’s stain)

94. Conclusion
 FNAC is a highly accurate procedure for differentiating
benign and malignant lesions.
 However, specific cytological diagnosis may be
difficult to make in the absence of characteristic
architectural patterns.
 Diagnosis of aspirates from cystic lesions may be less
specific than the solid lesions due to paucity of
specific lesional cells in the former and also due to
superimposed infection

95. Reference
 Gnepp, diagnostic surgical pathology of the head and
neck, 2nd edition.
 Surgical Pathology of the Head and Neck, Third
Edition, LEON BARNES
 Fine needle aspiration cytology, 4TH edition, Svante R
Orell.
 Fine needle aspiration cytology, Review article, JV
LEVER, PA TROTT, AJ WEBBA, J Clin Pathol
1985;38: 1-11.

96. Thank you