Cysts of the Orofacial Region

1
Cysts of the Orofacial Region

• Non-odontogenic developmental cysts
• Odontogenic cysts

2
Non-odontogenic Developmental Cysts

• Palatal Cysts of the Newborn
• Nasolabial Cyst
• Globulomaxillary Cyst
• Nasopalatine Duct Cyst
• Median Palatal Cyst
• Median Mandibular Cyst
• Epidermoid Cyst of the Skin
• Dermoid Cyst
• Thyroglossal Duct Cyst
• Branchial Cleft Cyst
• Oral Lymphoepithelial Cyst

3
Palatal Cysts of the Newborn

• Epsteins pearls occur along the median raphe of
  the hard palate (entrapped epithelium)
• Bohns nodules are scattered over the hard palate
  (minor salivary gland remnant epithelium)
• Common 1-3 mm white/yellowish papules
  innocuous, rupture and disappear

Bohns nodules
Epsteins pearls
4
Nasolabial CystNasoalveolar cyst, Nasolacrimal
duct cyst

• Rare soft tissue cyst 31F/M, 4-5th decades
• 10 bilateral
• Upper lip, lateral to the midline
• Elevates the ala of the nose compresses nares
  obliterates labial vestibule
• Respiratory epithelial lining
• Excision usually by intraoral approach

5
Nasolabial Cyst
6
Nasolabial Cyst
7
Nasolabial Cyst
Pseudostratified columnar epithelial lining.
Neville. Oral and Maxillofacial Pathology, 2nd
Edition. Elsevier, 2002.
8
Globulomaxillary CystGlobulomaxillary
Radiolucency

• Uncommon lesion that presents as an inverted
  pear-shaped radiolucency causing divergence of
  permanent maxillary lateral and canine teeth
• Probably odontogenic in origin (radicular cyst,
  keratocyst, lateral periodontal) based on
  histologic evidence
• Treatment by surgical enucleation c/s endodontic
  therapy

9
Globulomaxillary Lesions

• Nonspecific designation for any lesion in the
  globulomaxillary area (between maxillary lateral
  incisor and canine)
• Inverted pear-shaped radiolucency
• Asymptomatic teeth vital divergence of roots
• May represent odontogenic cyst or neoplasm, or
  non-odontogenic tumor
• Biopsy necessary to establish definitive
  diagnosis

Regezi. Oral Pathology Clinical Pathologic
Correlations, 4th Edition. Elsevier, 2002.
10
Nasopalatine Duct CystIncisive Canal Cyst,
Anterior Median Maxillary Cyst

• Most common non-odontogenic cyst of the jaws
  estimated to occur in 1 of population
• Believed to arise from remnants of nasopalatine
  ducts
• MgtF 4-6th decades
• Often asymptomatic may cause swelling, drainage
  or pain salty or sour taste
• Radiolucency of the incisive canal gt6mm classic
  heart-shaped
• Cyst of the incisive papilla if extrabony
• Surgical enucleation

11
Cyst of the Nasopalatine Canal
12
Cyst of the Nasopalatine Canal
Cystic lining ? showing transition from
pseudostratified columnar to stratified squamous
epithelium.
?Flattened cuboidal epithelial lining.
Cyst wall showing blood vessels, nerve bundles,
and mucous glands. Neville. Oral and
Maxillofacial Pathology, 2nd Edition. Elsevier,
2002.
13
Median Palatal CystMid-palatal Cyst, Median
Palatine Cyst

• Rare usually causes midline palatal swelling
  posterior to incisive papilla average 2 cm
• Can be difficult to distinguish from nasopalatine
  duct cyst in some cases
• Surgical enucleation

14
Histopathologic Featuresof Median Palatal Cyst

• Microscopic examination shows a cyst that is
  usually lined by stratified squamous epithelium.
• Areas of ciliated pseudostratified columnar
  epithelium have been reported in some cases.
• Chronic inflammation may be present in the cyst
  wall.

Neville. Oral and Maxillofacial Pathology, 2nd
Edition. Elsevier, 2002.
15
Median Mandibular Cyst

• Rare pathogenesis uncertain might be of
  odontogenic origin
• Between or apical to mandibular incisor teeth
• Surgical enucleation endodontic treatment might
  be indicated

16
Histopathologic Featuresof Median Mandibular Cyst

• The type of epithelial lining varies.
• The most common lining is composed of stratified
  squamous epithelium, and most of these cases may
  actually have been periapical or residual cysts.
• Some cysts in this location may be classified as
  odontogenic keratocysts or developmental lateral
  periodontal cysts.
• A few reported cysts have been lined with
  pseudostratified, ciliated columnar epithelium
  which raising the possibility of a fissural cyst
  in this location.
• These cases now may also fit into the category of
  glandular odontogenic cyst.

Neville. Oral and Maxillofacial Pathology, 2nd
Edition. Elsevier, 2002.
17
Epidermoid Cyst of the SkinInfundibular Cyst,
Epidermoid Inclusion Cyst
                                                
      ltgt

• Common cyst on acne-prone areas of head, neck
  back
• Teenagers and young adults MgtF
• Can be associated with Gardner syndrome
• May become inflamed Conservative excision

18
Epidermoid Cyst
A, Low-power view showing a keratin-filled cystic
cavity. B, High-powered view showing stratified
squamous epithelial lining with orthokeratin
production. Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002.
19
Dermoid CystBenign Cystic Teratoma Teratoid Cyst

• Developmental malformation that occurs most often
  in the ovary rarely as an oral dermoid cyst
• Oral examples most often in floor of the mouth,
  above or below the geniohyoid muscle children
  young adults
• Surgical removal

20
Dermoid Cyst
Squamous epithelial lining (top), with hair
follicle (F) and sebaceous glands (S) in the cyst
wall. Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
21
Thyroglossal Duct CystThyroglossal Tract Cyst

• Uncommon cyst arising from epithelial remnant of
  thyroglossal duct anywhere along the midline from
  the foramen cecum (tuberculum impar) to the
  thyroid gland
• Tongue lesions are rare most (60-80) below the
  hyoid bone 1st-2nd decades MF
• Painless, fluctuant, movable swelling
• Excision (Sistruck procedure) 10 recur lt1
  carcinoma

?
22
Thyroglossal Tract Cyst
Cyst (top) lined by stratified squamous
epithelium. Thyroid follicles can be seen in the
cyst wall (bottom). Neville. Oral and
Maxillofacial Pathology, 2nd Edition. Elsevier,
2002.
23
Branchial Cleft CystCervical Lymphoepithelial
Cyst Lateral Neck Cyst

• Probable entrapment of epithelium originating
  from a branchial cleft alternately parotid
  epithelium within lymph node
• Young adults 20-40 2Left1Right Fluctuant mass
  in the upper neck lateral neck along the anterior
  border of the sternocleidomastoid muscle
• Surgical removal

?
24
Branchial Cyst

• Developmental cystarises from epithelium
  entrapped in lymph node
• Lateral neck massalong anterior border of
  sternocleidomastoid muscle
• Fluctuant texture
• Young adults
• Lymphoid tissue surrounds a squamous or
  pseudostratified epithelial lining

Regezi. Oral Pathology Clinical Pathologic
Correlations, 4th Edition. Elsevier, 2002.
25
Lymphoepithelial cyst
Cyst lined by squamous epithelium (top) and
supported by lymphoid tissue.
26
Lymphoepithelial cyst
27
Oral Lymphoepithelial Cyst

• Uncommon entrapped or deep crypt epithelium
  within a lymph node
• Young adults 50 in floor of mouth most others
  ventral or lateral tongue, palatine tonsils or
  soft palate asymptomatic yellow/white submucosal
  mass
• Surgical excision

28
Odontogenic Cysts Learning Objectives

• Become familiar with the classification of
  odontogenic cysts
• Understand the derivation of the epithelium found
  in the various types of odontogenic cysts.
• Distinguish between types of odontogenic cysts
  based on location, radiographic and
  histolopathologic characteristics
• Appreciate the differences in biologic behavior
  of various odontogenic cysts.
• Accurate diagnosis of odontogenic cysts is
  sometimes problematic. It often requires a
  correlation of clinical, radiographic
  histopathologic findings for proper diagnosis.
  An understanding of histogenesis and recognition
  of certain microscopic characteristics, is most
  helpful. Although most odontogenic cysts are
  relatively non-aggressive, the odontogenic
  keratocyst is biologically distinct, may
  penetrate through bone into surrounding
  structures, recur and/or be associated with the
  Gorlin syndrome.

29
Cysts of the Jaws Epithelial Origin
(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.4.2.1)
30
Cap Stage of Tooth Development
(Avery, James K. Avery. Essentials of Oral
Histology and Embryology, 3rd Edition. Elsevier,
12/09/2005. 5.4).
(Moss-SalentiJn L, et al. Orofacial Histology
and Embryology. F.A. Davis. 1972).
31
Hertwigs Root Sheath Root Formation
(Nanci A. Ten Cates Oral Histology Development,
Structure and Function. 6th Edition. Mosby. 2003)
32
Epithelial Rests of Malassez
(Nanci A. Ten Cates Oral Histology Development,
Structure and Function. 6th Edition. Mosby. 2003)
(Moss-SalentiJn L, et al. Orofacial Histology
and Embryology. F.A. Davis. 1972).
33
Classification of Odontogenic Cysts

• DEVELOPMENTAL
• 1. Dentigerous cyst (follicular)2. Eruption
  cyst (hematoma)3. Odontogenic keratocyst
  (primordial)4. Orthokeratinized odontogenic
  cyst5. Gingival (alveolar) cyst of the
  newborn6. Gingival cyst of the adult7. Lateral
  periodontal cyst (botryoid)8. Calcifying
  odontogenic cyst (Gorlin)9. Glandular
  odontogenic cyst (sialo-odontogenic)INFLAMMATORY
  
• 1. Periapical or lateral cyst (apical or lateral
  radicular)2. Residual periapical cyst (residual
  radicular) 3. Buccal bifurcation cyst
  (paradental)

Neville. Oral and Maxillofacial Pathology, 2nd
Edition. Elsevier, 2002.
34
Dentigerous Cyst

• FREQUENCY Second most common odontogenic cyst
  after periapical cyst
• RADIOGRAPHIC FEATURES Lucency associated with
  crown of impacted tooth Third molars and canine
  teeth most commonly affected
• HISTOPATHOLOGY Lined by nonkeratinized
  stratified squamous epithelium Proliferation of
  reduced enamel epitheliumstimulus unknown
• POSSIBLE COMPLICATIONS Extensive bone
  destruction with growth Resorption of adjacent
  tooth roots Displacement of teeth Neoplastic
  transformation of lining (rare)ameloblastoma
  formation carcinoma very rarely

Regezi. Oral Pathology Clinical Pathologic
Correlations, 4th Edition. Elsevier, 2002.
35
Diagnosis of dentigerous cyst

• Because the histopathologic appearance of the
  lining epithelium is not specific, the diagnosis
  relies on the radiographic and surgical
  observation of the attachment of the cyst to the
  cementoenamel junction. A histopathologic
  examination must always be done to eliminate
  other possible lesions in this location.
• The size of the normal follicular space is 2 to 3
  mm. If the follicular space exceeds 5 mm, a
  dentigerous cyst is more likely.

• Stuart C. White. Oral Radiology, 5th Edition.
  Elsevier, 2003.

36
Differential diagnosis
A differential diagnosis of pericoronal
radiolucency should include odontogenic
keratocyst, ameloblastoma, and other odontogenic
tumors. Ameloblastic transformation of a
dentigerous cyst lining should also be part of
the differential diagnosis. Adenomatoid
odontogenic tumor would be a further
consideration with anterior pericoronal
radiolucencies, and ameloblastic fibroma would be
a possibility for lesions occurring in the
posterior jaws of young patients.
Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
37
Dentigerous cystCentral type showing the crown
projecting into the cystic cavity.
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
38
Dentigerous Cysts
(White, SC. Oral Radiology, 5th Edition. Mosby
Elsevier 2003.)
39
Dentigerous Cyst
40
Dentigerous cyst
(White, SC. Oral Radiology, 5th Edition. Mosby
Elsevier 2003.)
41
Dentigerous cystCircumferential variety showing
cyst extension along the mesial and distal roots
of the unerupted tooth
(Courtesy of Dr. Richard Marks.) (Neville, Brad
Neville. Oral and Maxillofacial Pathology, 2nd
Edition. Elsevier, 2002. 15.1.2.1).
42
Dentigerous Cyst (lined by a bilayer of cuboidal
epithelium similar to the reduced enamel
epithelium)
43
Dentigerous Cyst giving rise to ameloblastoma
44
Carcinoma ex Odontogenic Cyst
45
Eruption Cyst

• An eruption cyst results from fluid accumulation
  within the follicular space of an erupting tooth
• The epithelium lining this space is simply
  reduced enamel epithelium. With trauma, blood may
  appear within the tissue space, forming a
  so-called eruption hematoma.
• No treatment is needed, because the tooth erupts
  through the lesion. Subsequent to eruption, the
  cyst disappears spontaneously without
  complication.
• (Regezi, Joseph A. Regezi. Oral Pathology
  Clinical Pathologic Correlations, 4th Edition.
  Elsevier, 2002. 11.1.5).

46
Eruption Cyst
47
Eruption Cyst
48
Odontogenic Keratocyst Clinical Features

• Aggressive recurrence risk association with
  nevoid basal cell carcinoma syndrome
• Solitary cystscommon (5 to 15 of all
  odontogenic cysts) recurrence rate 10 to 30
• Multiple cysts5 of OKC patients recurrence
  greater than with solitary cysts
• Syndrome-associated, multiple cysts5 of OKC
  patients recurrence greater than with multiple
  cysts

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
49
Primordial cyst

• In the older classification of cysts used in the
  United States, the primordial cyst was considered
  to originate from cystic degeneration of the
  enamel organ epithelium before the development of
  dental hard tissue. Therefore, the primordial
  cyst occurs in place of a tooth.
• In the mid-1950s, the term odontogenic keratocyst
  was introduced in Europe to denote a cyst with
  specific histopathologic features and clinical
  behavior, which was believed to arise from the
  dental lamina. Subsequently, this concept was
  widely accepted, and the terms odontogenic
  keratocyst and primordial cyst were used
  synonymously. The 1972 WHO classification used
  the designation primordial cyst as the preferred
  term for this lesion but in 1992 lists
  odontogenic keratocyst as the preferred
  designation.

(Neville, Brad Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002. 15.1.4).
50
Odontogenic Keratocyst
51
Primordial cyst This patient gave no history of
extraction of the third molar. A cyst is located
in the third molar area. Histopathologic
examination revealed an odontogenic keratocyst
(Neville, Brad Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002. 15.1.2.1).
52
Odontogenic keratocyst

• Major diagnostic histopathologic criteria
• Refractile, parakeratotic lining
• Thin epithelium (6 to 10 cell layers)
• Palisaded, polarized nuclei of basal cell layer
• Other features
• Epithelial budding and "daughter cysts"
• Characteristic features often lost with
  inflammation

(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.7.3.1).
53
Odontogenic keratocyst Showing characteristic
parakeratinized lining with basal cell
polarization.
(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.7.5).
54
Odontogenic keratocystThe epithelial lining is 6
to 8 cells thick, with a hyperchromatic and
palisaded basal cell layer. Note the corrugated
parakeratotic surface.
(Neville, Brad Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002. 15.1.2.1).
55
Odontogenic keratocystEpithelium exhibiting
characteristic loss of adhesion to underlying
connective tissue.
(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.7.5).
56
Odontogenic keratocyst showing loss of
characteristic features in areas of inflammation,
as well as mural daughter cysts/rests.
(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.7.5).
57
Odontogenic keratocyst. Positive staining cells
(brown) for antiapoptosis protein Bcl-2.
(Regezi, Joseph A. Regezi. Oral Pathology
Clinical Pathologic Correlations, 4th Edition.
Elsevier, 2002. 11.1.7.5).
58
Major Clinical Features of the Nevoid Basal Cell
Carcinoma Syndrome

• 50 OR GREATER FREQUENCY
• ? Multiple basal cell carcinomas
• ? Odontogenic keratocysts
• ? Epidermal cysts of the skin
• ? Palmar/plantar pits
• ? Calcified falx cerebri
• ? Enlarged head circumference
• ? Rib anomalies (splayed, fused, partially
  missing, bifid)
• ? Mild ocular hypertelorism
• ? Spina bífida occulta of cervical or thoracic
  vertebrae
• From Gorlin RJ Nevoid basal-cell carcinoma
  syndrome, Medicine 6698113, 1987.

59
Major Clinical Features of the Nevoid Basal Cell
Carcinoma Syndrome

• 15 TO 49 FREQUENCY
• ? Calcified ovarian fibromas
• ? Short fourth metacarpals
• ? Kyphoscoliosis or other vertebral anomalies
• ? Pectus excavatum or carinatum
• ? Strabismus (exotropia)
• From Gorlin RJ Nevoid basal-cell carcinoma
  syndrome, Medicine 6698113, 1987.

60
Major Clinical Features of the Nevoid Basal Cell
Carcinoma Syndrome

• LESS THAN 15 FREQUENCY (BUT NOT RANDOM)
• ? Medulloblastoma
• ? Meningioma
• ? Lymphomesenteric cysts
• ? Cardiac fibroma
• ? Fetal rhabdomyoma
• ? Marfanoid build
• ? Cleft lip and/or palate
• ? Hypogonadism in males
• ? Mental retardation
• From Gorlin RJ Nevoid basal-cell carcinoma
  syndrome, Medicine 6698113, 1987.

61
Gorlin Syndrome (Basal Cell Nevus )Frequency
est. 1/55,600

• Genetics Cancer - Basal Cell Nevus Syndrome
  (Gorlin Syndrome)
• Basal Cell Nevus Syndrome (Gorlin Syndrome)
• The risk for ovarian cancer is increased with
  basal cell nevus syndrome (also called Gorlin
  syndrome and nevoid basal cell carcinoma), a rare
  autosomal dominant cancer genetic syndrome.
  Approximately 600 cases have been identified.
  Features associated with basal cell nevus
  syndrome may include the following
• development of more than two basal cell
  carcinomas (cancer of the outer layer of the
  skin) before the age of 30
• cysts in the jaw
• characteristic facial appearance (60 percent of
  people)
• calcification of the falx (a variation in the
  appearance of the skull that is visible on
  x-rays)
• pits in the palms and soles of the feet
• eye abnormalities
• rib or vertebral abnormalities
• increased risk of medulloblastoma
• increased risk of cardiac and ovarian fibromas
  (benign, or noncancerous, tumors)
• Basal cell nevus syndrome is caused by a tumor
  suppressor gene, called PTCH, located on
  chromosome 9. Mutations in this gene may increase
  the risk of ovarian cancer.
• Tumor suppressor genes usually control cell
  growth and cell death. Both copies of a tumor
  suppressor gene must be altered, or mutated,
  before a person will develop cancer. With basal
  cell nevus syndrome, the first mutation is
  inherited from either the mother or the father in
  60 percent to 80 percent of cases. In 20 percent
  to 40 percent of cases, the first mutation is not
  inherited and arises de novo (for the first time)
  in the fertilized egg from which the person with
  symptoms was conceived. Whether de novo or
  inherited, this first mutation is present in all
  of the cells of the body and, as such, is called
  a germline mutation.
• Whether a person who has a germline mutation will
  develop cancer and where the cancer(s) will
  develop depends upon where (which cell type) the
  second mutation occurs. For example, if the
  second mutation is in the skin, then skin cancer
  may develop. If it is in the ovary, then ovarian
  cancer may develop. The process of tumor
  development actually requires mutations in
  multiple growth control genes. Loss of both
  copies of PTCH is just the first step in the
  process. What causes of these additional
  mutations to be acquired is unknown. Possible
  causes include chemical, physical, or biological
  environmental exposures (such as sunlight) or
  chance errors in cell replication.
• Some individuals who have inherited a germline
  tumor suppressor gene mutation may never develop
  cancer because they never get the second mutation
  necessary to knock out the function of the gene
  and start the process of tumor formation. This
  can make the cancer appear to skip generations in
  a family, when, in reality the mutation is
  present. Persons with a mutation, regardless of
  whether they develop cancer, however, have a
  50/50 chance to pass the mutation on to the next
  generation.
• It is also important to remember that the gene
  responsible for basal cell nevus syndrome is not
  located on the sex chromosomes. Therefore,
  mutations can be inherited from the mother or the
  father's side of the family.

62
Gorlin Syndrome(Basal Cell Nevus Syndrome)
63
Nevoid basal cell carcinoma (nevus) syndrome

• Odontogenic keratocyst showing numerous
  odontogenic epithelial rests in the cyst wall.

(Neville, Brad Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002. 15.1.7.3).
64
Orthokeratinized Odontogenic Cyst

• Less common than the parakeratinized odontogenic
  keratocyst
• Not syndrome associated
• Lower recurrence rate than the parakeratinized
  odontogenic keratocyst

65
Orthokeratinized Odontogenic CystA large cyst
involving a horizontally impacted lower third
molar. On microscopic examination, this was an
orthokeratinized odontogenic cyst
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
66
Orthokeratinized Odontogenic Cyst Note granular
layer subjacent to keratin and lack of basal cell
organization.
Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
67
Orthokeratinized Odontogenic CystMicroscopic
features showing a thin epithelial lining. The
basal epithelial layer does not demonstrate
palisading. Prominent keratohyaline granules are
present beneath the orthokeratotic surface.
Flakes of orthokeratin are present in the lumen.
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
68
Gingival Cyst of the Newborn(Dental lamina cyst
of the newborn)

• Common up to 50 of newborns
• Maxillary alveolar ridge mucosa gtMandible
  usually 2-3 mm diameter
• Derived from remnants of the dental lamina
• Lined by stratified squamous epithelium lumen
  may be filled with keratin
• Spontaneous rupture with disappearance usually
  before three months of age

69
Gingival Cyst of the Newborn
70
Gingival Cyst Of The Adult

• An uncommon lesion.
• It is considered to represent the soft tissue
  counterpart of the lateral periodontal cyst being
  derived from rests of the dental lamina (rests of
  Serres).
• The diagnosis of gingival cyst of the adult
  should be restricted to lesions with the same
  histopathologic features as those of the lateral
  periodontal cyst.
• On rare occasions, a cyst may develop in the
  gingiva at the site of a gingival graft however,
  such lesions probably represent epithelial
  inclusion cysts that are a result of the surgical
  procedure.

Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
71
Gingival Cyst Of The AdultTense, fluid-filled
swelling on the facial gingiva. Low-power
photomicrograph showing a thin-walled cyst in the
gingival soft tissue.(insert).
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
72
Gingival Cyst of the Adult Cyst lined by thin,
nonkeratinized epithelium.
73
Gingival Cyst of the Adult
74
Lateral Periodontal Cyst

• Relatively uncommon asymptomatic ?2 of
  developmental odontogenic cyst
• Develops lateral to root surface most common
  (75-80) in mandibular canine-premolar region
• 5th-7th decades well-circumscribed radiolucency
  adjacent teeth vital
• Thin squamous to cuboidal epithelial lining
  sometimes with nodular thickening (clear cells)
• Occasionally botryoid grossly or parakeratotic
  type of odontogenic keratocyst microscopically

Gross specimen of a botryoid variant.
Microscopically, ? this grapelike cluster
revealed three separate cavities.
75
Lateral Periodontal CystRelative distribution of
lateral periodontal cysts in the jaws
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
76
Lateral Periodontal CystThis photomicrograph
shows a thin epithelial lining with focal nodular
thickenings. These thickenings often show a
swirling appearance of the cells (inset).
Brad Neville. Oral and Maxillofacial Pathology,
2nd Edition. Elsevier, 2002.
77
Lateral Periodontal Cyst
78
Lateral Periodontal Cyst
79
Calcifying Odontogenic Cyst (Gorlin)

• CLINICAL FEATURES
• No distinctive age, gender, or location
• Lucent to mixed radiographic patterns
• HISTOPATHOLOGY
• Basal palisading
• Ghost cells and dystrophic calcification
• Similar to pilomatrixoma of skin
• BEHAVIOR
• Unpredictable
• VARIANTS
• Odontogenic ghost cell tumorsolid
• Odontogenic ghost cell carcinomacytologic atypia

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
80
Calcifying Odontogenic Cyst

• Wide age range, with a peak incidence in the
  second decade. It usually appears in individuals
  younger than 40 years of age and has a decided
  predilection for females.
• More than 70 of COCs are seen in the maxilla.
  Rarely COCs may present as localized extraosseous
  masses involving the gingiva. Those presenting in
  an extraosseous or peripheral location are
  usually noted in individuals older than 50 years
  of age and are found anterior to the first molar
  region.
• Radiographically, COCs may present as unilocular
  or multilocular radiolucencies with discrete,
  well-demarcated margins. Within the radiolucency
  there may be scattered, irregularly sized
  calcifications.

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
81
Calcifying Odontogenic Cyst

• Most COCs present as well-delineated cystic
  proliferations with a fibrous connective tissue
  wall lined by odontogenic epithelium.
• Intraluminal epithelial proliferation
  occasionally obscures the cyst lumen, thereby
  producing the impression of a solid tumor.
• The epithelial lining is of variable thickness.
  The basal epithelium may focally be quite
  prominent, with hyperchromatic nuclei and a
  cuboidal to columnar pattern.
• Above the basal layer are more loosely arranged
  epithelial cells, sometimes resembling the
  stellate reticulum of the enamel organ.
• The most prominent and unique microscopic feature
  is the presence of so-called ghost cell
  keratinization. The ghost cells are anucleate and
  retain the outline of the cell membrane. These
  cells undergo dystrophic mineralization
  characterized by fine basophilic granularity,
  which may eventually result in large sheets of
  calcified material. On occasion, ghost cells may
  become displaced in the connective tissue wall,
  eliciting a foreign-body giant cell response.

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
82
Calcifying Odontogenic Cyst
83
Calcifying Odontogenic Cyst
84
Calcifying Odontogenic Cyst Showing
keratinized epithelial cells (ghost cells)
filling the lumen (left)
Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
85
Calcifying Odontogenic Cyst
86
Glandular Odontogenic Cyst(Sialo-odontogenic
cyst)

• FREQUENCY Rare developmental cyst (first
  described in 1987)
• CLINICAL FEATURES Adults mean age 50 M F
  often multilocular
• Either jaw 80 mandible (anterior gt posterior)
• HISTOPATHOLOGY Focal mucous cells, pseudoducts
  Can resemble low-grade mucoepidermoid carcinoma
• BEHAVIOR Locally aggressive recurrence
  potential (25)

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
87
Glandular Odontogenic Cyst
88
Histopathology of Glandular Odontogenic Cyst
?Special stain for mucous cells (aqua)
89
Periapical Cyst (Apical Periodontal Cyst) -
Clinical Features

• Periapical cysts constitute approximately
  one-half to three-fourths of all cysts in the
  jaws.
• The age distribution peaks in the third through
  sixth decades. Of note is the relative rarity of
  periapical cysts in the first decade, even though
  caries and non-vital teeth are rather common in
  this age-group.
• Most cysts are located in the maxilla, especially
  the anterior region, followed by the maxillary
  posterior region, the mandibular posterior
  region, and finally the mandibular anterior
  region.

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
90
Periapical (Radicular) Cyst - Developmental
sequence.
Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
91
Periapical Granulomas (associated with non-vital
teeth).
Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
92
Periapical Granuloma (inflamed connective tissue
granulation tissue)
93
Periapical Cyst

• Epithelium at the apex of a non-vital tooth can
  be presumably stimulated by inflammation to form
  a true epithelium-lined cyst.
• The inflammatory response appears to increase the
  production of keratinocyte growth factor by
  periodontal stroma cells, leading to increased
  proliferation of normally quiescent epithelium in
  the area.
• The source of the epithelium is usually a rest of
  Malassez but also may be traced to crevicular
  epithelium, sinus lining, or epithelial lining of
  fistulous tracts.
• Cyst development is common the reported
  frequency varies from 7 to 54 of periapical
  radiolucencies.
• On occasion, a similar cyst, best termed a
  lateral radicular cyst, may appear along the
  lateral aspect of the root.
• Periapical inflammatory tissue that is not
  curetted at the time of tooth removal may give
  rise to an inflammatory cyst called a residual
  periapical cyst.

94
Periapical Cyst

• The radiographic pattern is identical to that of
  a periapical granuloma.
• Cysts may develop even in small periapical
  radiolucencies, and the radiographic size cannot
  be used for the definitive diagnosis. T
• There is a loss of the lamina dura along the
  adjacent root, and a rounded radiolucency
  encircles the affected tooth apex. Root
  resorption is common.
• With enlargement, the radiolucency often flattens
  out as it approaches adjacent teeth. Significant
  growth is possible, and lesions occupying an
  entire quadrant have been noted.
• Although periapical cysts more frequently achieve
  greater size than periapical granulomas, neither
  the size nor the shape of the lesion can be
  considered a definitive diagnostic criterion.

95
Periapical Cyst
96
Lateral Radicular Cyst
97
Histopathology of the Periapical Cyst

• The periapical cyst is lined by nonkeratinized
  stratified squamous epithelium of variable
  thickness.
• Transmigration of inflammatory cells through the
  epithelium is common, with large numbers of PMNs
  and fewer numbers of lymphocytes involved.
• The underlying supportive connective tissue may
  be focally or diffusely infiltrated with a mixed
  inflammatory cell population.
• Plasma cell infiltrates and associated refractile
  and spherical intracellular Russell bodies,
  representing accumulated gamma globulin, are
  often found and sometimes dominate the
  microscopic picture.
• Foci of dystrophic calcification, cholesterol
  clefts, lipid-laden macrophages and
  multinucleated foreign body-type giant cells may
  be seen subsequent to hemorrhage in the cyst
  wall. Pulse or seed granulomas are also
  occasionally found in periapical cyst walls,
  indicating apical communication with the oral
  cavity through the root canal and carious lesion.

Joseph A. Regezi. Oral Pathology Clinical
Pathologic Correlations, 4th Edition. Elsevier,
2002.
98
Periapical CystNote a chronic inflammatory
cell infiltrate and nonkeratinized epithelial
lining.
99
Periapical Cyst
100
Periapical Cyst
cholesterol slits
Rushton bodies
foam cells
101
Residual periapical (radicular) cyst

• A residual cyst is a cyst that remains after
  incomplete removal of the original cyst. The term
  residual is used most often for a radicular cyst
  that may be left behind most commonly after
  extraction of a tooth.
• If either a residual cyst or the original
  periapical cyst remains untreated, continued
  growth can cause significant bone resorption and
  weakening of the mandible or maxilla.
• Complete bone repair is usually seen in
  adequately treated periapical and residual cysts.

102
Residual periapical (radicular) cystPersistent
radiolucency at site of previous tooth extraction.
(Neville, Brad Neville. Oral and Maxillofacial
Pathology, 2nd Edition. Elsevier, 2002. 3.5.2).
103
Buccal Bifurcation Cyst

• Two theories of pathogenesis
• From epithelial cell rests in the periodontal
  membrane of the buccal bifurcation of mandibular
  molars.
• Type of dentigerous cyst (paradental) lateral to
  an erupted molar
• Occurs most in children aged 5-11 years.
• Slight-to-moderate tenderness on the buccal
  aspect of the mandibular first molar, which may
  be in the process of erupting.
• The patient often notes associated clinical
  swelling and a foul-tasting discharge.
  Periodontal probing usually reveals pocket
  formation on the buccal aspect of the involved
  tooth.
• Around one third of patients have been reported
  to have bilateral involvement of the first
  molars.
• Similar histologically to dentigerous, c/s
  inflammation

104
Buccal Bifurcation (Paradental) Cyst)
BBC associated with a mandibular molar, gross
specimen.
Regezi. Oral Pathology Clinical Pathologic
Correlations, 4th Edition. Elsevier, 2002.
105
Buccal bifurcation cyst

• The most striking diagnostic characteristic of a
  BBC is the tipping of the involved molar so that
  the root tips are pushed into the lingual
  cortical plate of the mandible and the occlusal
  surface is tipped toward the buccal aspect of the
  mandible.
• If the cyst is large enough, it may displace and
  resorb the adjacent teeth and cause a
  considerable amount of smooth expansion.

(White, Stuart C. White. Oral Radiology, 5th
Edition. Elsevier, 2003. 24.3.4).