Odontogenic Cysts Dr. T Flashcards
1
Q
What are the two types of Odontogenic Cysts?
A
Inflammatory
or
Developmental
2
Q
List the type of Inflammatory cysts
(4)
A
- Periapical (radicular)
- Residual periapical
- Buccal bifurcation
- Paradental
3
Q
List the types of Developmental Cysts?
(9)
A
‐ Dentigerous
‐ Eruption
‐ Gingival cyst of newborn
‐ Gingival cyst of adult
‐ Lateral periodontal
‐ Glandular odontogenic
‐ Odontogenic keratocyst
‐ Orthokeratinized odontogenic
‐ Calcifying Odontogenic
4
Q
All of the following are histologically the same because they are all what?
-Periapical (radicular)
‐ Residual periapical
‐ Buccal bifurcation
‐ Paradental
‐ Dentigerous
‐ Eruption
‐ Gingival cyst of newborn
‐ Gingival cyst of adult
A
squamous epithelial lined cysts
5
Q
What are the sources of epithelium
within the jaw bone ?
(6 sources)
A
▪ Epithelial rests of Malessez
▪ Reduced enamel epithelium
▪ Fissural cysts – when 2 pieces of bone come together
▪ Odontogenic cysts
▪ Epithelial component of odontogenic tumors
▪ Salivary gland inclusions – rare, incorporated in development
6
Q
radicular cyst, inflammatory cyst are other names for
A
Periapical Cysts
7
Q
▪ The most common cyst of the jaws
A
Periapical Cysts
8
Q
Periapical Cysts
Demographic and location
A
▪ Any age (peak in 3rd ‐ 6th decades, rare in 1st decade)
▪ No sex predilection
▪ MX > MD (anterior MX most common)
9
Q
Tooth vitality and Periapical Cysts
A
- Involved tooth usually non‐vital/non‐responsive with thermal and electric pulp testing
- Should test vitality of tooth if see radiolucency in apex\
- If tooth vital, and still see radiolucency ► should do biopsy
10
Q
Periapical Cyst
(Radiographic)
A
- Usually appears as well‐circumscribed periapical radiolucency with widening of the PDL space and/or loss of lamina dura
- Typically small (< 1 cm) but can grow to large dimensions if left untreated
- Radiographic findings can NOT be used for definitive diagnosis
11
Q
Why the Radiographic findings of Periapical Cyst can NOT be used for definitive diagnosis?
A
‐ similar appearance with:
- periapical granuloma
- odontogenic tumors
- early COD {Cemento Osseous Dysplasia}
12
Q
Lateral radicular cyst appears on the lateral surface of the root of a non‐vital/non‐responsive tooth
‐ A differential for which cyst?
A
lateral periodontal cyst
13
Q
What is this radiographic finding?
A
Periapical Cysts
►Would need to test both teeth for vitality.
14
Q
What is this radiographic finding?
A
Periapical Cyst
15
Q
What is this radiographic & clinical findings?
A
Periapical cyst
shows inflammation at site
abscess developed fistula tract thru
soft tissue. Pt will have pain until
pressure is released
16
Q
The wall of which cyst?
A
Periapical Cyst
Open clear areas = Cholesterol clefts where fat
used to be. Multinucleated cells (purple dots)
trying to break down cholesterol
17
Q
What is this and what is it associated with?
A
keratin pearl – can be associated w/SCC
18
Q
Periapical Cyst
treatment
A
- endodontic therapy or extraction of involved teeth
- larger lesions may require biopsy along with endodontic therapy
- lesions which fail to resolve should be biopsied
- follow-up at 1-2 years
19
Q
Residual Cyst
Etiology
A
- After tooth extracted, not properly cleaned ► the residual cells of the cyst lining and inflammatory cells continue to proliferate
- Has to be at site where tooth was previously removed
20
Q
Residual Cyst
Radigraphically
A
- well defined round to oval radiolucency in the site of a previous extraction
21
Q
Residual Cyst
Histologically is identical to which cyst?
A
- identical to the radicular cyst (periapical cyst)
- Should biopsy to rule out other causes
22
Q
Residual Cyst
Treatment
A
-Removal
- Enucleation if small
- Marsupialization if large
- Note:*
- Enucleation* means: removal of an organ or other mass intact from its supporting tissues
Marsupialization means: surgical technique of cutting a slit into an abscess or cyst to empty its contents and suturing the edges of the slit to form a continuous surface from the exterior surface to the interior surface of the cyst or abscess.
Promotes Decompressing and shrinkage.
23
Q
What are these radiographic findings?
A
Residual Cysts
24
Q
What is the radiographic finding?
A
Residual Cyst
25
**Paradental Cyst**
_Etiology_
Some controversy over this designation
‐ some think they are inflammatory cyst
‐ some think they are developmental cysts
▪ Etiology: _remains unclear_
26
**Paradental Cyst**
_Radiographically_
* Radiolucent area noted
* most frequently, along the distal aspect of an impacted or partially erupted third molar
27
Which cyst has been associated w/ enamel extensions into furcation areas of the
involved teeth?
**Paradental Cyst**
28
**Paradental Cyst**
_Treatment_
**Extraction** of the _tooth along with the lesion_
29
What is the radiographic finding?
Paradental Cyst
30
What is the radiographic finding?
Paradental Cyst
31
**Buccal Bifurcation Cyst**
is similar to what Cyst ?
_Similar to **a paradental cyst**_
‐ **EXCEPT**: location is _central on the buccal of mandibular first molars_
32
**Buccal Bifurcation Cyst**
_Etiology_
unclear
33
**Buccal Bifurcation Cyst** is most commonly seen with eruption of what tooth?
The eruption of ***the permanent first molar***
34
**Buccal Bifurcation Cyst**
_Clinically_
seen as
* swelling
* tenderness of soft tissue over involved area
35
Which
Radiograph type is best to see
**Buccal Bifurcation Cyst?**
▪ Radiolucency best seen with **an occlusal radiograph**
36
What is the radiographic finding?
**Buccal Bifurcation Cyst**
*as seen in occlusal radiographs*
37
What is the radiographic finding?
**Buccal Bifurcation Cyst**
*as seen in occlusal radiographs*
38
Buccal Bifurcation Cyst
_Treatment_
▪ **Enucleation** **of cyst**; tooth extraction unnecessary
▪ Some cases _resolve w/o surgery_
▪ Some resolve _w/ daily irrigation_ of buccal pocket with saline/hydrogen peroxide
39
**Dentigerous Cyst**
also known as ?
**Follicular Cyst**
40
What is **most common type of developmental odontogenic** **cysts?**
20% of all epithelial lined cysts of the jaw
**Dentigerous Cyst**
41
**Dentigerous Cyst**
_Origin_ & _Etiology_
*_Originates_*: by **the separation** of the _follicle_ from the _crown of an unerupted tooth_
*_Pathogenesis_*: **accumulation of fluid** between the tooth and the _reduced enamel epithelium_
42
Dentigerous Cyst
_Clinically_
▪ Small cysts typically asymptomatic and picked up
on routine radiographic exam
▪ Large lesions may show expansion of bone
▪ Cysts may become infected, especially if partially erupted
tooth
43
Dentigerous Cyst
_Demographics_ & _Location_
* Mostly **mandibular 3rd molars** (rarely unerupted deciduous teeth)
* Most commonly present in **2nd and 3rd decades**
44
What is a key characteristic of **Dentigerous Cyst** _location_?
* **Attached to the tooth at the CEJ**
45
Small Dentigerous Cyst
are hard to differentiate radiographically from ---?
**enlarged/hyperplastic follicle**
Rule of thumb:
* If 4‐5mm or more of radiolucency ► _dentigerous cyst_
* If \<4mm of radiolucency► can be _hyperplastic follicle_
46
dentigerous cyst or
follicle ?
_dentigerous cys_t
b/c **\*attachment at CEJ**
47
What is the radiographic finding?
**Dentigerous Cyst**
48
What are these radiographic findings?
**dentigerous cyst**
49
What are these radiographic findings?
**dentigerous cyst**
50
What is the radiographic finding?
**dentigerous cyst**
51
What is this gross finding?
Grossly image of
## Footnote
**Dentigerous Cyst**
52
Dentigerous Cyst
Treatment
* **Decompression**: Try to open window in the jawand put tube into cyst lumen and have pt irrigate a few times a day for a few weeks ► release pressure and allows bone to grow back ► **cyst will shrink**
* If get rid of whole area surgically► c_an risk_ _fracturing the jaw_
53
What is the Soft tissue counterpart of a dentigerous cyst?
Eruption Cyst
54
**Eruption Cyst** also known as
_eruption hematoma_
55
**Eruption Cyst**
Etiology
* Results from accumulation of fluid in the follicular space when the tooth has erupted over the alveolar bone **\*NOT in bone\***
56
**Eruption Cyst**
_Demographic_ & _Location_
▪ Usually seen in **1st decade** *(children)*
▪ Most often involves **1st permanent molar** and **maxillary incisors**
57
**Eruption Cyst**
Clinically
Frequently _normal mucosal color_, BUT surface trauma (ex. chewing) may result in bleeding into the cystic space► may look **purple or blue**
▪ Usually **soft** or **fluctuant**(like a balloon) _upon palpation_
58
**Eruption Cyst**
_Treatment_
* Unless symptomatic, no treatment required, cysts resolve upon eruption of teeth
59
What is the clinical finding?
**Eruption Cyst**
60
What is the clinical finding?
**Eruption Cyst**
61
**Cysts of the Newborn**
can either be --- or ---
**Palatal cysts**
or
**Gingival cyst**
62
**Palatal cysts**
_Types_
_&_
_Location_
**‐ Bohn’s nodules:** scattered over HP (hard palate), often junction of HP and SP (soft palate)
**‐ Epstein’s pearls:** along median palatal raphe
63
Cysts of the Newborn:
**Palatal cysts**
_Demographics_
* Seen in 60‐80% of neonates
64
Cysts of the Newborn:
**Palatal cysts**
_Clinically_
* 1‐3 mm cream to white papules (keratin filled cysts)
## Footnote
**\*NOT in bone\***
65
Cysts of the Newborn:
Palatal cysts
Treatment
**No treatment is required**
‐ Resolve (degenerate or rupture) on their own in a
few months
‐ Once baby eats solid foods, will go away
66
What is the clinical finding?
Cysts of the Newborn:
Palatal cysts
67
Cysts of the Newborn:
**Gingival cyst of the Newborn**
Also known as
**Dental lamina cysts**
68
Gingival cyst of the newborn
_demographics & Location_
* Found superficially on the **alveolar ridge mucosa**
* **MX** \> MD
* Rarely seen after 3 mos. of age
69
**Gingival cyst of the newborn**
_Treatment_
▪ No treatment is necessary
▪ Spontaneously resolve (degenerate or rupture)
70
**Gingival cyst of the newborn**
_Clinically_
* 1‐3 mm creamy white papule (keratin filled cysts)
* \*NOT in bone\*
71
Gingival cyst of the newborn/ Dental lamina cysts/Cysts of the Newborn-gingival
72
What is the soft tissue counterpart of the **lateral periodontal cyst ?**
**Gingival Cyst of the Adult**
73
Gingival Cyst of the Adult
_Origin_
Derived from dental lamina rests
**‐ Rests of Serres**
74
**Gingival Cyst of the
Adult**
_Demogrophic & Location_
**▪Uncommon lesion**
▪ 60‐75% **mandibular canine/premolar area**
‐ most common location on the _facial or buccal aspect_
▪ **5th and 6th decade** most common
75
**Gingival Cyst of the
Adult**
_Clinically_
* Painless, dome‐like swellings up to 5 mm in diamete
* Often with a bluish or grayish hue
76
**Gingival Cyst of the
Adult**
has _similar histology_ to which cyst?
**lateral periodontal cyst**
77
**Gingival Cyst of the
Adult**
_Treatment_
* **simple surgical excision**
* _Unlikely_ to recur/come back
78
What is the clinical finding?
**Gingival Cyst of the
Adult**
79
What is the clinical finding?
Gingival Cyst of the
Adult
80
What is the clinical finding?
Gingival Cyst of the
Adult
notice the _bluish hue_
81
**Lateral Periodontal Cyst** represents the intrabony counterpart of which cyst?
**gingival cyst of the adult?**
82
Lateral Periodontal
Cyst
_Origins_
* Developmental cyst believed to arise from **dental lamina rests**
83
**Lateral Periodontal cyst** is diagonsed when cysts occur in the _lateral periodontal region_ and after what have been excluded?
* **an inflammatory origin cysts** or t**he diagnosis of odontogenickeratocyst** _have been excluded_
84
**Lateral Periodontal Cyst**
_Charcterstics_ and _tooth vitality_
▪ Commonly **asymptomatic** and _found on routine radiographic exam_
▪ Associated teeth tests **vital/responsive with electric pulp test**
85
if you see a radilucency Lateral to a teeth
how would you know if it's
Lateral Periodontal Cyst
or
Lateral Radicular Cyst
or
Lateral OKc
‐ **If pulp alive**► **lateral periodontal cyst** or ***Lateral Okc ( if huge lesion)***
‐ If pulp dead► **lateral radicular cyst**
86
**Lateral Periodontal Cyst**
_Demographic_ and _Location_
▪ Most likely found after age 30
▪ Males\>Females
**▪ ~65% mandibular canine/premolar area**
‐ Can also be seen _between canine and lateral incisor_
87
**Lateral Periodontal Cyst**
_Radiographically_
Present as **well circumscribed**, **unilocular** _radiolucencies between 2 teeth,_ located **lateral to tooth root**
▪ Most often **0.5‐1.0 cm** in diameter
▪ Radiographic features are **NOT** diagnostic
88
Which is here is
**Lateral Periodontal Cyst**
**Lateral Radicular Cyst**
**Lateral Odontogenic Kertocyst**
* Could be differential for lateral Odontogenic keratocyst, except this does not grow in size
* Lateral radicular cysts from an accessory canal if tooth is non vital
* or it could be Lateral Periodontal Cyst if tooth is vital!
89
What is the radiographical finding?
**Lateral Periodontal
Cyst**
90
What is the radiographical finding?
**Lateral Periodontal
Cyst**
91
What is the histological finding?
**Lateral Periodontal Cyst**
see the _alternating
thin to thick epithelium_
***a characteristic of these cysts***
92
What is the histological finding?
**Lateral Periodontal Cyst**
93
Lateral Periodontal
Cyst
_Treatment_
* consists of **conservative enucleation**
94
What cyst is a **variant of lateral periodontal cyst?**
**Botryoid Odontogenic
Cyst**
95
**Botryoid Odontogenic
Cyst**
_Grossly_ and _Microscopically_
shows **a grape‐like cluster** of small
individual cysts
96
**Botryoid Odontogenic
Cyst**
_Radiographically_
▪ Either unilocular or multilocular on radiographs, depending on size of the lesion
▪ Cyst lining similar to lateral periodontal cyst
97
What is the radiographical finding?
**Botryoid Odontogenic
Cyst**
well circumscribed, between 2 teeth (similar to
lateral odontogenic cyst), multilocular
98
What is the radiographical finding?
**Botryoid Odontogenic
Cyst**
99
**Glandular Odontogenic
Cyst**
_Charcterstics_
* **A rare odontogenic cyst** which exhibits features of _glandular differentiation within the epithelium_
* Presumably **represents the pluripotentiality of odontogenic epithelium**
100
Glandular Odontogenic
Cyst
_Demographics_
▪ Wide age range from 2nd to 9th decades
**‐** *_mean age 49_*
**▪ ~ 80% of cases in mandible
▪ Anterior lesions**
‐ More common
‐ _May cross the midline_
101
**Glandular Odontogenic
Cyst**
_Radiographically_
▪ Uni‐ or (more often) multilocular radiolucency
▪ **Well‐defined** with **a sclerotic border**
102
**Glandular Odontogenic
Cyst**
reccurance rate
(~ 25% recurrence rate)
Can be locally aggressive
103
Glandular Odontogenic
Cyst
_Clinically_
▪ Usually asymptomatic unless inflamed
104
**“Primordial” Cyst**
why it is _controversial!_
* **Mixed up with OkC**
* Originally meant to describe cyst which **develops in bone at a site where a tooth was meant to develop (usually a third molar)**
* If this lesion exists, **it is truly rare and would have histology distinct from OKC**
* * In the current literature, reference has been almost _nonexistent_
105
What is the radiographical finding?
**“Primordial” Cyst**
Assuming histologically it is *different from OKC*
106
“Primordial” Cyst
is **not** a true -------
* lesion, *was actually some other type of cyst*
* * it is now thought that most of the reported Primordial cysts were actually **OKCs**
107
**Odontogenic
Keratocyst**
**OKC**
_Also known as_
**keratocystic odontogenic tumor (KOT)** -2005 WHO
_but now it's back to **OKC**_
108
**Odontogenic
Keratocyst (OKC)**
_Etiology_
* **Growth and expansion** of this lesion due not only to osmotic effects/pressure, but to _unusual gene expressions_
109
Which **unusal gene expression** causes _growth and expansion of OKC_ ?
* _Expresses **Ki‐67**_ (high rate of cell proliferation)
* O_verexpression of **Bcl‐2**_ (antipoptotic protein)
* _Overexpression of **MMP’s 2 and 9**_ (thought to allow growth into connective tissue)
* _Mutation of **PTCH**_, a tumor suppressor gene
* when PTCH is non‐functional → cell proliferation
110
**Odontogenic
Keratocyst (OKC)**
_Demographic & Location_
* ~ **60%** present in **2nd and 3rd decade**, but can occur at any age
* **Mandible** affected in 60‐80% of cases
* tendency to occur in **posterior mandible and ramus**
* **25‐40% of cases involve an unerupted tooth**
* ‐ **5%** of patients have **_multiple cysts_**
111
**Odontogenic
Keratocyst (OKC)**
differes from
**Meloblastoma**
**in its growth pattern**
**Odontogenic Keratocyst (OKC) :**grows in anterior to posterior manner before causing cortical expansion
*while*
**Meloblastoma:** causes **cortical expansion _early_**
112
Which cyst make up **~10‐15%** of all **odontogenic cysts?**
**Odontogenic
Keratocyst (OKC)**
113
5% of **Odontogenic
Keratocyst (OKC)** are associated with _which syndrome?_
**nevoid basal cell carcinoma
syndrome**(*_**Gorlin syndrome**)_*
114
What are the site distribution of OKC?
Most of OKC in
posterior region
115
Odontogenic
Keratocyst
_Reccurance Rate_
* **HIGH Recurrence Rate**
* **Benign**, but _locally aggressive biologic behavior_
* _Solitary OKCs have_ ~**10% recurrence rate with appropriate treatment**
* _Multiple OKCs hav_e ~ **30% recurrence rate**
116
**Odontogenic
Keratocyst**
**(OKC)**
_Reccurance Rate Order_
from **highest** to **lowest** reccurance rate
**Syndrome OKC \> Multiple OKC \> Solitary OKC \> Conventional odontogenic cysts**
117
**Odontogenic
Keratocyst**
**OKC**
_Radiographically_
* Usually **a well‐circumscribed** *_radiolucency_* with **smooth, often** **corticated margins**
▪ Cysts may be
‐ **Unilocular** (most common)
‐ **Multilocular** (larger lesions)
118
**Odontogenic
Keratocyst**
**OKC**
_clinically_
▪ **Small cysts** are typically **asymptomatic** and picked up on routine radiographic exam
▪ **Larger cysts** may or may not be asymptomatic
▪ \*Cysts tend to grow in an antero‐posterior direction prior to lateral growth ►_therefore cysts are usually quite large when they start to expand the cortical plate_
119
**Odontogenic
Keratocyst**
**OKC**
Has similar Radiographic findings with ?
* dentigerous cyst
* ameloblastoma
* and others
120
**Odontogenic
Keratocyst
OKC**
_Treatment_
▪ **Marsupialization** (decompression)
▪ **Peripheral ostectomy**
‐ Carnoy’s solution
▪ **Resection**
▪ **Medications targeted to PTCH**
▪ ***Long term follow‐up***
121
What is the radiographical finding?
**Odontogenic
Keratocyst
OKC**
122
What is the radiographical finding?
**Odontogenic
Keratocyst
OKC**
123
What is the radiographical finding?
**Odontogenic
Keratocyst
OKC**
124
What is the radiographical finding?
**Odontogenic
Keratocyst
OKC**
125
What is the radiographical finding?
similar to
*lateral
periodontal cyst*
but is actually
**OKC**
126
What is the histological finding?
Odontogenic
Keratocyst
Histology
Notice the daughter cysts
127
**Nevoid Basal Cell Carcinoma
Syndrome**
is also known as ----- ?
**Basal Cell Nevus or Bifid Rib Syndrome**
or
**Gorlin syndrome**
128
Which cyst is assoicated with
Nevoid Basal Cell Carcinoma
Syndrome
?
**Odontogenic Keratocyst
“OKC”**
129
**Nevoid Basal Cell Carcinoma
Syndrome**
**(Gorlin syndrome)**
_modes of inheritanc_e
**_Autosomal dominant_ inheritance**
130
Which **_Gene mutation and pathway_**
_associated with_
**Nevoid Basal Cell Carcinoma
Syndrome**
**(Gorlin syndrome)**
* _Mutation_ of **PTCH** (tumor suppressor gene)
* in the **Sonic Hedge Hog pathway**
131
**Nevoid Basal Cell Carcinoma
Syndrome**
_Prognosis_
■ Prognosis _depends on progression of skin tumors_
132
**Nevoid Basal Cell Carcinoma
Syndrome**
_Treatment_
✎Surgery (typically MOHS)
✎Sometimes curette them
✎ Radiation therapy (RT) is typically not the first line of therapy with small lesions RT
✎Cryotherapy which means they just use a little liquid nitrogen and freeze them
✎Photodynamic therapy with photosensitizer and topical medications
■ New medication: **Vismodegib _inhibits sonic hedgehog pathway by binding smoothened (SMO)_**
* *suppressive rather than curative cause it seems to work for short time and after ~7-8 months ..may also helps _suppress growth of OKC_*
133
What is this radiographic finding?
✎A patient who has **Nevoid Basal Cell Carcinoma
Syndrome**
✎We can see **multiple cystics** areas and lesions in
_the jaws, maxillary and mandible_
✎**Both 3rd molar displaced** in the maxilla because of
the cyst
134
What is this radiographic finding?
✎**Multiple lesions**, impacted 3rd molar in mandible
and displaced 3rd molar up into the sinus,
✎These too many lesions hard to manage the issue
with a surgery
✎This large area on the left mandible – good example of why we do
decompression because if you just remove this lesion
and the entire area is left open, this would be an area
risk for fracture
135
What is this called
which can be seen with
Nevoid Basal Cell Carcinoma
Syndrome
✎An example of the **pitting** that can be seen **palmar
and plantar**
~ This is a side of a hand
✎This is an early stage of basal carcinoma which
never goes on (like it is aborted)
136
What are these **findings** that is associated with
## Footnote
**Nevoid Basal Cell Carcinoma
Syndrome?**
* **thousands of basal cell carcinoma** is developing on the skin
-very difficult to manage with surgery,
~ That’s why they remove
the larger ones, the deeper ones ~ They leave the one
that’s less as an issue until they get to a larger size to
be removed
137
Why **Basal Cell Carcinoma** is very problematic ?
It’s not the lesion themselves causing metastasis
that’s the issue, it’s the lesion growing deeply and in affecting adjacent structures that really is the
issue with basal carcinoma
138
What is the **Most common type of skin cancer?**
**Basal Cell Carcinoma
(BCC)**
139
**Basal Cell Carcinoma
(BCC**)
_Demographics_
* 2-3 million cases a year
* About 3 out of 4 skin cancers are basal cell carcinomas
140
Basal Cell Carcinoma
_Growth_ and _location_
| (BCC)
- Develop in the **lowest layer of the epidermis**, called the **basal Laye**r
- Develops on sun-exposed areas: _cumulative DNA Damage_
**- Slow-growing**
• If not treated, basal cell c**ancer can grow into nearby areas
and invade the bone or other tissues beneath the skin**
141
Basal Cell Carcinoma
_Progrssion_
| (BCC)
within 5 years of being diagnosed with
BCC►**35%-50%** of people _develop a new skin cancer_
142
**Calcifying Odontogenic Cyst**
**COC**
also known as
?
* **Calcifying Cystic Odontogenic Tumor**
* **_Gorlin Cyst_ ( don't confuse it with Gorlin syndrome)**
* **Ghost Cell Tumor**
*
143
**Calcifying Odontogenic Cyst
(COC)**
can present in **3 types**
1. **■ Cystic Unilocular COC**
* COC with odontoma (~ 20%)
* Extraosseous/peripheral – present in _older patients_
2. **■ Solid COC (odontogenic ghost cell tumor)**
* Often demonstrate _a more aggressive behavior_
* WHO once considered them all CCOT now back to COC
3. ■ **Odontogenic ghost cell carcinoma**
* _very rare lesion_
144
**Collision Tumors** is a term used to describe lesions involving Calcifying Odontogenic Cyst (COC), what does that mean?
* where you see **_both features_ of ameloblastoma with COC** or **adenomatoid odontogenic tumor with COC**
145
**Calcifying Odontogenic Cyst
(COC)**
_may occur in association_
_with_
**which tumors or cysts?**
* **Odontomas** (a benign tumour linked to tooth development)
* **Ameloblastomas** (rare, noncancerous (benign) tumor)
* **Adenomatoid odontogenic tumor** (rare tumor of epithelial origin that is benign, painless, noninvasive, and slow-growing)
146
**Calcifying Odontogenic Cyst
(COC)**
_Demographics & Location_
■ Peak in _second decade_, most **before age of 40**
■ Frequently presents **anterior to molars**
■ ~ **20% extraosseous (peripheral)**, found in **older age group** (~ 50 years of age)
■ Female \> Male
■ **~ 70% occur in MX**
■ One third are associated with **unerupted teeth**, usually a **canine**
147
Calcifying Odontogenic Cyst
_Radiographically_
| (COC)
■ Usually **a well-circumscribed unilocular radiolucency,** _infrequent multilocular cases_
■ **One third to one half** show _radiopaque structures within the radiolucency_
■ When you see **calcifications** within a lesion, you don't use the term uni or multi locular anymore, but they are called **_mixed radiolucent/radiopaque lesions_**
■ May cause **resorption or displacement of roots**
**■** **_One third_** are associated with **unerupted** **Canine**
148
What is this radiographic finding?
```
**Calcifying
Odontogenic Cyst (COC)**
```
* _in the mandible_ and you can see it **well circumscribed radiolucency**
* a little bit of blunt root resorption in this area
* _No calcifications_ in this one yet ►so this is still **unilocular radiolucency**
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What are the _clinical_ and _radiographic_ findings here?
What is this lesion?
* Clinical finding for this patient was **Obliteration of the vestibule space**, because the mandible is showing expansion
* radiographically:we see radiolucency going as far as the first molar
* This is a **mixed radiolucent radiopaque lesion** in developing calcifications.
* This is an example of **Calcifying** **Odontogenic Cyst (COC)**
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The hallmark of Calcifying
Odontogenic Cyst COC Histology is
**_Ghost cells_**
They have that sort of polygonal shape or roundish shape with the pink that looks like the cytoplasm, but in
the location where the nucleus would have then, there's an empty spot
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Histologically speaking, Calcifying
Odontogenic Cyst COC, basically
looks similar to what epithelium?
**_ameloblastic epithelium_**
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**Calcifying Odontogenic Cyst COC**
_Treatment_
■**Enucleation with peripheral ostectomy** ~ Very similar to odontogenic keratosis
■ **Follow up is long term** because s_ome of the solid tumors have a more aggressive behavior_
**■ Peripheral lesions are treated with excision**
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When COC is associated with another tumor, ameloblastoma, how would you treat?
■ the treatment is based on **the more aggressive tumor**
**~** So you would treat the _ameloblastoma_.
~You wouldn't treat conservatively the COC though
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**Odontogenic ghost cell carcinoma**
_Prognosis_
**(5 year survival ~ 70%).**
* It is _rare_ and shows _cytologic atypia histologically_
* It has an _unpredictable biologic behavior_
