OP Sheet #10 By Noor Khammash

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OP Sheet #10 By Noor Khammash

Post by Sura on 10/12/2011, 6:00 pm


عدد المساهمات : 484
النشاط : 2
تاريخ التسجيل : 2010-09-29

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Re: OP Sheet #10 By Noor Khammash

Post by Shadi Jarrar on 23/12/2011, 9:06 pm

Odontogenic tumor:

Squamous odontogenic tumor:

It is a rare tumor, appears as a well circumscribed radiolucency with sclerotic border between the roots.

Its radiographic appearance reminds us with: either lateral periodontal cyst or sever periodontal disease with sever bone loss.


· It occurs in young adults, the molars region. It’s a painless swelling as all the benign tumors

· It might cause displacement of teeth

· Origin: Rest cells of malessez


Unilocular/ semilunar triangular radiolucency between the teeth


· It consists of irregular shaped island of well-differentiated benign looking squamous epithelium, that’s why it’s called squamous odontogenic tumor

· Histologically it can be mistaken with intraosseous squamous cell carcinoma

· In these island we can find cystic spaces and formation of keratin or calcification>>>>which is responsible for “radiolucency inside it radio-opacity” appearance

Calcifying epithelial odontogenic tumor (pindborg tumor)

It is a rare tumor that represents 1% of all odontogenic tumor


· It occurs in adult, slowly painless swelling, occurs in mandible twice as maxilla, mainly in molar and premolar sites

· It can be extraosseous lesion at the tip of the gingiva, then it’s called peripheral CEOT >>almost 5% of the cases

· Progression: similar to ameloblastoma

· CEOT is locally invasive , and it’s reminds us with ameloblastoma but it’s less invasive with less recurrence


· Multilocular or an irregular area of radiolucency and radio-opacity, appears as snow. when the radio-opacity increases>>>it’s called “derived snow appearance” .

· It’s associated with un erupted tooth


· Though it is a benign tumor but it’s histological appearance looks like malignant one

· Sheets of polyhedral epithelial cells with abundant eosinophilic cytoplasm

· Pleomorphism, multinucleation, but no mitotic division

· It’s a benign tumor and between its cells there is an amyloid like material

· Amyloid like material may calcify>>to form spherical calcification

Adenomatoid odontogenic tumor

It is a benign tumor, it’s called adenoid(related to gland) because of its histological appearance


· Young patient comes with localized swelling at the canine area

Differential diagnosis:

· Dentigerous cyst

How to differentiate?

1. Dentigerous cyst starts from the dentino- enamel junction while adenoid tumor from the root

2. Dentigerous cyst appears as a well defined radiolucency whereas the adenomatoid odontogenic tumor appears as a well defined radiolucency with flecks of radio-opacities.


· Well defined unilocular radiolucency, that surrounds the root. Sometimes calcification occurs>>>radiolucency inside it radio-opacity

· Prognosis: Very good, No recurrence

· Treatment or management: extraction of the tooth and manipulation of lesion.

· Some consider it as hemartoma, but we DONT


· Fibrous connective tissue capsule

· Solid or cystic spaces (partially cystic)

· Histologically it appears as whorls

· Epithelium organized inside the cystic space as whorl masses then it differentiates into columnar to give the duct appearance

And as we said it’s surrounded by capsule>>if we removed the tumor with its capsule you will have a duct like structure with spherical calcification

Ameloblastic fibroma/fibrodentinoma/fibroodontoma:

Both components are neoplastic (the epithelium and mesenchymal elements), whereas in ameloblastoma only the epithelium is neoplastic


· It appears in younger patients compared to ameloblastoma (14 years)

· Slowly grows , painless, same region of ameloblastoma >>>molar and premolar regions of the mandible and the ramus

· Associated with un erupted tooth or missing teeth


· Well defined Uni/multi locular radiolucency.

· *ameloblastoma is multi locular.


· Thin strands of odontogenic epithelium

· Like the fibroma there are fibroblast that form loose connective tissue, resembling dental papilla of mature pulp!

· There are Stellate reticular cells but they are less abundant compared to ameloblastoma

· Sometimes dentine is formed around these strands,

o Rreduction of the surrounded tissue and formation of odontoblasts, odontoblasts forms dentine>>then it’s called ameloblastic fibro dentinoma

o If enamel is formed>>it is called ameloblastic fibroodontoma

· It has a rosette appearance..(it looks like a small rose).

· Good prognosis/not invasive!


· It is a dangerous tumor, and it’s behavior is similar to ameloblastoma

· It is an ameloblastoma with enamel and dentine like structures

· Recurrence rate is high

· Clinically it should be treated as ameloblastoma not odontoma

Calcifying cystic odontogenic tumor

It used to be called classifying odontogenic cyst

Solid cases it’s called dentinogenic ghost cell tumor


· It appears in an area anterior to the six tooth.

· Patients are Usually younger than 40 years

· Swelling, painless lesion

· 25% of the cases it’s extra bony (extraosseous) so it includes soft tissue

Prognosis: solid is more aggressive than soft cystic lesion


· Well defined uni /multilocular radiolucency contains radio-opacity

· It might be associated with un erupted tooth

o Most of the odontogenic tumors are difficult to diagnose unless we take a biopsy.


· Cystic cavity lined by basal ameloblast like cells and stellate reticular cells in the rest of the layers

· It looks like ameloblastoma but the difference is the presence of the large keratocyte cells with their nuclei at the peripheries,sometimes no boundries, fused together. we refer to these cells as (ghost cells), and they give this tumor the ghost appearance

· Ghost cells may calcify and forms dentine like matrix or even odontoma

Odontogenic fibroma and myxoma

It originate from:

Periodontal ligament, dentinal follicle, dental papilaa

Odontogenic fibroma:


· Slow, painless enlargement in the gingiva of the mandible..

· It can be mistaken with fibrous epulis..(when it is peripheral) Or keratocyst in radiographs (when it is in the bone)


· Well defined radiolucency around one of the tooth


· Mature collagen and spindle-shaped fibroblasts

· Strands of odontogenic epithelium

· Foci of cells and dentine like matrix

· Recurrence rate is low

Odontogenic myxoma:


· More common than odontogenic fibroma

· It occurs in maxilla at the same rate of the mandible

· It’s a low, painless enlargement that develops faster than odontogenic fibroma

· It can cause tooth displacement

· It can be mistaken with keratocyst and ameloblastoma


· Well defined radiolucency with or without root resorption

· It gives soap bubble like appearance, or bee cells/honey cells appearance>>>(radiolucency with radio-opaque separation)

· The best description is tennis racket appearance.>>straight radio-opaque lines


· No capsule so there is infiltration to the surrounded tissue>>>while odontogenic fibroma has capsule.

· Widely separated angular cells with long anastomosing process

· Mucoid ground substance

· With island of odontogenic epithelium and Focal calcifications

o Mixed odontogenic fibroma and myxoma:

o When the percentage of fibroma is more>>it’s called myxofibroma

o When the myxoma is more>>it is fibromyxoma

Benign cementoblastoma:

the only true neoplasm of cementum, and it appears in young patients


· It occurs in males more than females, at age less than 25 years

· It’s found at the mandibular molar(first molar) and premolar regions.

· Slow enlargement/swelling

· Sometimes gives rise to pain so you examine the patient for carious lesions and you can’t find any!!

· Tooth is vital


· Well defined radio-opaque dense mass attached to the root of vital tooth, with thin radiolucent margin which represents the capsule.

· One root or both roots of the 1st mandibular molar

· It can cause resorption of the related roots

Prognosis: is good, extraction of the tooth or dissection of the mass without extraction of the tooth. No recurrence.


· Capsulated tumor

· Peripheral zone of un-mineralized tissue containing active cementoblasts.

· Same appearance of cellular cementum.

Malignant odontogenic tumors:

Malignant odontoblastoma

· Typical histology of ameloblastoma

· Pulmonary metastasis

· It’s been found that the ameloblastoma tissue (normally in the jaw) is present in the lung of some patients. It’s due to aspiration of these tissue during surgery


· Benign looking ameloblast tissue, no signs of malignancy, does not metastasize via blood

Ameloblastic carcinoma:

· It is an Ameloblastoma with loss of differentiation of the cells.

· It shows signs of malignancy

Polymorphism,hypermorphism, high mitotic activity, destruction of the surrounding tissue.

· In some patient>>>it spreads to lymph node and other distant organ

Primary intraosseous squamous cell carcinoma:

· Squamous cell carcinoma inside the bone jaw

· Originate from surface epithelium (Odontogenic epithelium), not the mucosa

· It shows Signs of malignancy, destruction of bone, resorption of roots.

Clear cell odontogenic carcinoma:

· It looks like renal cell carcinoma

· It shows signs of malignancy.


· poorly circumscribed sheets of cells with clear, glycogen-rich cytoplasm, it looks like renal cell carcinoma

· The question is whether it is primary odontogenic carcinoma or secondary (it has metastasized from kidney to jaw)!!

· Patients with this tumor need more investigation>>>kidney diseases!

Malignant change in odontogenic cysts:

· Clinically and radiographically it appears as a cyst

· Histologically it appears as carcinoma, and cyst

There are three theories:

1. Either it’s a carcinomal change in a cyst

2. Or cystic degeneration in a carcinoma

3. Or carcinoma invading the walls/borders of a cyst

Odontogenic sarcomas:

· Non-neoplastic odontogenic epithelium

· one example is: Ameloblastic fibrosarcoma

· Ameloblastic fibrosarcoma is same of ameloblastic fibroma but with signs of malignancy

Tumors of debatable origin:

Congenital gingival granular cell tumor,(congenital epulis)


· Newborn

· Anterior maxilla>>>premaxilla

· Occurs in females ten times more than males

· Pedunculated swelling from crest of alveolar ridge >>>it can grows to the degree of causing Suffocation >>difficulty in breathing>>>needs immediate intervention/management

· No spontaneous healing>>>it needs excision


· Sheath of granular cells>>>large cells, with granular cytoplasm, round nuclei

· Atrophy of overlying epithelium.

· It looks like granular cell tumors bs there are some differences which are:

In congenital gingival granular cell tumor:

· Atrophy of overlying epithelium

· Negative result when a special stain for “neural crest” is used

In granular cell tumor, (connective tissue tumor):

· The covering stratified squamous epithelium shows pseudo-epitheliomatous hyperplasia

· Positive result when a special stain for “neural crest” is used>>>indicates its neural origin!

Melanotic neuroectodermal tumor of infancy:

Origin: neural crest


· Newborns: younger than six months

· Brown to black pigmented swelling, must be differentiated from the congenital epulis

o Epuils is pedunculated swelling, Melanotic neuroectodermal tumor of infancy is just a swelling in the alveolar ridge, and it’s dark in color

· Sites:Ant maxilla(pre maxilla)

· It’s found in other extra oral sites: such as brain, skull,

· High urinary mandelic acid>>>related to neural crest and it indicates it’s origin


· Radiolucency with teeth and tooth buds displacement, root resorption


· Two cell types and dense fibrous connective tissue stroma

· Large with open nucleus and melanin granules in cytoplasm

· Small cells that look like leukocytes with dark dense nucleus and scant cytoplasm.

Lecture number:11

Lecture date: 28/11

Best of luck!!
Shadi Jarrar
مشرف عام

عدد المساهمات : 997
النشاط : 12
تاريخ التسجيل : 2009-08-28
العمر : 28
الموقع : Amman-Jordan


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