Script # 12 .. Bone disorders 4

8/3/2019 Script # 12 .. Bone disorders 4

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Part one : By Osama Yousef

Before we start talking about Paget‟s disease of bone, you have to know the

following things :

Osteoclast Bone resorption .

Osteoblast Bone deposition.

Paget‟s disease of bone is of unknown etiology, there are hypothesis about the

etiology of this disease, but most of the cases are of unknown etiology.

Normally there is a balance between the activity of bone deposition and bone

resorption and this is called normal bone remolding, but in Paget‟s disease of bone

this balance is not kept. We have excessive or abnormal : bone resorption or in

other words : Osteoclast function , either it is excessive ; hyperosteoclast function

or abnormal .

In Paget‟s disease of bone there are three overlapping phases :

1. The first phase is called “Predominantly osteolytic phase “: there is excessive

osteoclast activity (or excessive bone resportion) in this stage the radiograph

will be radiolucent (more black in color).

2. The second phase will be a mix between osteolytic (bone resorption ) and

osteoblastic ( bone deposition ) , all of which are taking place at the same time.



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3. The third phase is the “Sclerotic phase or Osteosclerotic bone“ where the

osteoblastic activity is the predominant and the bone becomes osteoscleraotic

the bone will show the following signs in this stage :

Dense, hard , brittle, easily fractured upon extraction and with low blood

supply, all of these signs might lead to osteomaliets and bone infectionwhich will be discussed in later occasions

The first phase and second phase, we will have excessive bleeding because of

increases of vascularity in the marrow spaces, in fact we have too much vascularity

the patient might have heart failure. The second phase could be also considered as

a vascular phase. So the complications of the first and second phase is excessive

bleeding and hemorrhage after extraction due to high vsacularity

Deformity of bones will occur in the first and second phases. In the third phase it‟llfix the deformity and make it dense or; sclerotic.

It should be noted that Paget‟s disease of bone is a chronic disease .

The disease is most common in areas such as United kingdom, Australia and

North America, in fact in England because they wear hats, the patient will

complain about their hats are getting smaller in size, but what‟s actually happing is

that their skulls are getting bigger!

We are going to talk about the sgins of Paget‟s disease in different areas of the

human body .

The effects on the bones can be summed up as follows :

1. There is bony deformity, the head becomes large.

2. The femur in legs will have curved apperance

3. the sacrum in the vertebral column is also affected (giving the bend

appearance).



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Not all the bones are necessarily affected, the patient may have the disease but with

only one bone deformed, or in other cases the patient may have the disease but

there are no signs to tell ; it can be only discovered with biopsy from that patient ,

so either single bone , multiple bones or not discovered at all.

4. we can see raidographically ( the

adjacent picture ) that the skull is very

dense and we can‟t differentiate the

outer cortex (dipole) of the skull nor

we can differentiate the tables of the

skull. One of the complications of the

large skull is the pressure on nerves.

This pattern of whitish you see iscalled “ cotton wool” appearance.

The effects of Paget‟s disease on the oral area can be summed as follows :

1. What is important in this disease for us as a dentists is the maxilla, there is

going to be changes in the maxilla. It will be affected it will be enlarged in sizeand when the maxilla is enlarged ,the teeth are going to be spaced and the

denture will not fit as it used to be , so the patient might need occasional

changes of the maxillary denture to make it fit.

2. Spaced teeth

3. The teeth may also be palatally inclined (retro inclaniaiton )



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4. hypercemntosis and the ankylosis , ankylosis as you already know is the fusion

between cementum and bone without PDL space .

5. We also might have root resorption , which will occur mainly in the first phase .

6. We also might have Post-extraction hemorrhage and More prone to infection in

sclerotic phase as we said earlier.

7. Widening of the alveolar ridges

8.Abnormal occlusion

Due to hypercemntosis and ankylosis in Paget‟s disease , there might be surgical

complications because the tooth won‟t come out easily.

9. Loss of the lamina dura in teeth , what is the lamina dura ? It is the compact

bone or dense bone it appears radiographically as white lines surroding the teeth,

these white lines have spaces between them and the root and within this space we



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have the PDL. It‟ll be lost in Paget‟s disease due to bone resorption and when there

will be bone deposition there will be hypercemntosis as we said earlier , so it will

be lost.

Note that Paget‟s disease of bone is more cmmon in maxialla.

Now we come to the etiology part, what is the cause of all of these changes?

Unknown cause : paramyxovirus infection affecting the osteoclasts

Genetic predisposition : Chromosome 18q locus defect or might be

genetically related to familial tendency

In the first osteolytic phase we can see hyperosteoclastic (multi-nucleated) , they

are called “scalloping of the margins of the bone “ .

When reverse of the activity of resorption occurs, a thin scallop line with a

different color compared to the bone will occur, why these lines are formed?

Because these lines are not well mineralized as the rest of the bone, because there

is a sudden change in the bone activity either resorpition or deposition or

formation.

As you can see in the pictures A and B (on next page ) these blue lines on the H&E

stain, it is called reversal lines because there is a reverse in the activity between

osteoblastic and osteoclastic . You will have to know that, this general pattern of

bone is called “ Mosaic pattern “ , we call it mosaic because we have small

piceses of bone surrounded by these blue lines. So this mosaic appearance will

indicate the reversal activity.

If you look at the picture A, you can see that we are on the 2nd

phase and we are

moving toward to the 3rd

phase . How did I know that? Well, most of the bone are

sclerotic and there are a few blood vessels (arrows), we say that these are blood



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vessels because if you look closer you can see endothelial lining. You should note

that determining the phases is a hard thing, because often they are overlapping.

Increased serum alkaline phosphatase this reflects the bone resorption or

deposition

Serum calcium and phosphorus occasionally increased usually within

normal limits. (There is change in the calcium/phosphor but they are in the

normal range) .

In order to treat Paget‟s disease patient we have to stop the osteoclastic activity,

and we do this by giving Calcitonin and diphosphonates .



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Paget‟s disease is usually not fetal, but it creates lesions inside the bones and these

lesions might lead to increased incidence of malignant neoplasms , most common

type of the malignat complications is osteosarcoma. Note that the incidence for

this is <1%.

You should also remember the default sings of paget‟s disease of bone which we

discussed earlier as, skull enlargement and the maxilla denture problems related to

this disease which may count also as complactions.

Question : “Are each phase of the three phases with a fixed timing “ ? the answer

was : “ no , they have no specific timing , they are overlapping but the leastduration would be the first phase “.

Question:” You said that Paget‟s disease affects the maxilla; does it affect the

mandi ble as well?” Yes it does, but the maxilla rate is greater and it is more

commonly involved, it depends on which bone the disease choose to infect .

As we said, one of the complications of Paget‟s disease is the lesions that are

inside the bone , looking at this picture which phase is this picture indicating ? it is

the first because we have too many osteoclasts activity and scalloped border of the

bone. ( picture of gaint cell lesion , next page )

The doctor said that we have already talked about central giant granuloma and we

have already compared it with hyper-para-thyrodism , honestly she just passed the

slides without talking too much about it , it is up to you if you want to study it or

not.



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It is not common in children and it is not of developmental cause , in the past they

thought that it had a developmental connection to it , but it turned out not to be ,

because if it were developmental how come we can‟t see it more in children .

Some say it increases in size because of masticatory function, especially patients of

burixsm habit , but if you think about it there isn‟t much of muscles movement

going on the palate so it is just one of the theories , other causes is unknown of

why it changes in size . But burixsim habit has a link to it.

This change in size due to the muscles pull might be more evident in the torus

mandibularis , which will be discussed next .

It is found at the lingual aspect, present above the mylohyoid line , it is found in

90% bilateral . Note that torus palatinus is more common than torus mandibularis

They are neither benign nor malignant tumors so they are not tumors at all! , still

their significance comes from:

The denture of the patient will not fit propbley as it used to be.



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The dentist might not understand what are the

raidopacity that are present (look the x-ray). The

dentist might be confused with the diagnoses,

until he meets the patient and discover these

toruies , see picture A.

They occur in the Buccal aspect of the alveolar

bone and mainly on the maxillary teeth, people

with “gum smile “will be more concerned than

normal people because these Buccal exostoses

will be more shown .

What you have to do is only reassurance you

have to explain to them that these are just

developmental changes and there is absolutely

no need to worry, if they are too much worried,

and then you can make a surgical removal for

them.

Like the Buccal exostosis we can also have palatal

exostosis (picture), they may occur palatal to the last

molar area.



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We also have Subpontine exostosis which is after extraction of the tooth and

constriction of a denture or a bridge there might be exostotic mass, why it formed

there? Well maybe because it is reactive in the space provided by the denture or

bridge.~ note this exostosis is not mentioned in the book.

It is composed of dense compact bone (look picture),

you can notice the few bone marrow spaces. Most of

the time the histopathology is dense compact bone.

Dense bone island is of idopathic cause ,

you may see that the tooth is, not havinglow grade infection ,it is not carious and the

bone is not cemnto-ostasis dysplisa because

it is not surrondeed by raidolucent area , it

is not causing bone expanison so in this

case you call it dense bone islnad or bone

scar , as the scars in the skin.

It might not be fused to the root or it might be fused to the root , looking at the

picture above the doctor asked to give some dignoses for it . Some answered that it

might be hypercemntosis the dr said no because hypercemntosis occuer in the root

surface and the hypercemntosis will still show the PDL space , unlike the picture.

Others said concrescence , again the dr said no because in the concrescence you

can‟t find dense bone areas within the bone itself , the concrescence is just fusion

of the roots between adjacent teeth with cemntum , here if you take a look you



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It is a true benging tumor of bone meaning that it will keep enlarging in size slowly

with time, it is usually not multiple like the Buccal exstosis and not present in the

midline of the palate nor the above the mylohyoid line . It is usually found at the angle of the mandible.

It could be sub periosteal (immediately below the perotisum) or diffused within

the bone (central ). The ostoemoa may be compact or cancellous bone .

Looking at picture A, what is this mass? Is it soft tissue ? No , it is a bony mass

, that is found at the angle of the mandible and if you look at the radiograph you

can notice that it is a bony mass , it is denser than the bone , so it is osteomoa.

It requires surgical removal because it is continuosaly growing , unlinke buccal

exoseosis they don‟t require surgical treatment expect when denture

constriaction or cosmatic reasons.

Looking at picture B, what do you think this disease is if you knew it is

continuously enlarging its size. Is it osteoma or Buccal exostosis ? The answer is

osteomoa because it is continuously enlarging in size and because it is found as a

single proturbrance , Buccal exosteosis is found multiple and not only one.

But if the osteoma are multiple in a single patient we should think about Gardner

syndrome (we discussed gardner syndrome in the middle exam material, we said

that gadrnder syndrome had a relation with multiple supernumerary teeth).



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The patients of this syndrome will have premalagenit adenomas of the colon, and

100% of those patients will have adenocarcinoma of the intestine .

What shall we do for these patients ? Actually they cut their colon as prohylaxis

to make sure they don’t get the worse case which is the adecnocarcinoma of the

intestine.

It is Autosomal dominenet

Polyposis coli marked tendency for malignant change

Fibrous tumors

Sebacous cysts of the skin

Multiple impacted and supernumerary teeth

Looking at the picture A , you can see we have two

osteomoma , so this person might have Gardner syndrome ,

so genetic analysis is important for this patient .

Looking at picture B , you can notice that the osteomia is

not below the bone it is actually wihtin the bone so it is of

central type. It looks also cancilous bone , not very dense.

A student asked a question “ from picture B , sometimes we

might get confiused between exosteosis and osteomoa “ .

The answer was as follows : “ No , this is osteomia because

of two things :

1. In oral pathology we don‟t have a single exososs

apperaing at the angle of the mandbile

2. The angle of the mandbile is a common place for

osteoma



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A student asked another question “ The buccl exosteosis looks simillar to what we

saw in the ginvial cysts “ . The answer was “ during the clinc trial , upon palpation

the cyst will show fluid materials , while the osteoma will be a bony mass ; will not

show fluid “.

It is a true benign slow growing tumor of bone that consists of mature bone.

It is more frequent in the mandible than the maxilla.

It may arise as Sub periosteal or central.

Multiple osteomas is a feature of Gardner Syndrome.

With this we finished talking about osteoma .

Is a benign tumor but locally aggressive.

It may destroy the cortical plates of bone,

and may reach big sizes and cause fracture to

the mandible.

Histologically ,, Osteoblastoma are totally

different from Osteoma…. The doctor didn't talk

about these differences.

Microscopically, may be confused with

Osteosarcoma because it has active cells

within it.

Clinically and radiographically may look like Cementoblastoma. But thedifference is that Osteoblastoma is separated from the cementum of the root.



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Is a Benign tumor of cementum

It is well demarcated from the surrounding

bone It is fused with the cementum of the root.

It's increasing in size because it's a true

tumor of bone.

Dense lesion that has mixed radiolucent

and radiopaque according to the activity of the

cells, with a surrounding radiolucent line.

*** In the adjacent picture, Well defined

rounded radilucent small area between the roots of mandibular premolarsis Mental Foramena !!

Is a malignant tumor of bone

The malignant cells in it are osteoblast .

** The normal product of osteoblast is bone, the immature bone is called

woven bone, and the matrix of this immature bone is called osteoid ,which

is not well mineralized yet.

It will have malignant osteoblast that will form osteoid which will be

malignant, too.

Most common primary malignant tumor in jaws.

*** Primary tumors come from the bone itself, but Secondary tumors

come from metastasis NOT from the bone itself and it may come from

the oral epithelium in the oral cavity.



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The age of onset is around 30 a little bit later than osteosarcoma in other

long bone in the body ,

May be central, or may start from under the periosteom which is easier to

be diagnosed.

The mandible will have better prognosis, because the maxilla may have

many marrow spaces that the osteosarcoma may spread through them easily

and early .

Ostoesarcoma may increase in paget's deiseas of bones.

The arrow points to osteoid because it ishomogenous; dense eosinophilic that will

absorb eosin stain, so it will be red in

color.

Bone is mineralized in the center but at

periphery it's still young "non-

mineralized".

The cells that form this dense bone is

malignant osteoblast are polymorphic;

they vary in shape (oval or irregular)

,size (small or big )and stain (hyper-

chromatic or not ).

The problem is that it doesn‟t show bone formation ""In microscopic

pictures ,when there is a sample with no bone formation then it's so

difficult to say it's osteosarcoma,so it will need different stains and

procedures"".



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Malignant tumors are rapidly

growing, therefore they don‟t give

time to the body to form a welldefined corticated region; ill-defined

radiolucent region.

This lesion will eat everything (the

roots, the bone).

It may perforate through the cortex

causing expansion of the bone.

May go inside PDL causing

symmetrical widening.

It may go out the soft tissue and

produce rapidly enlargement lesion

with ulceration later on, because the

epithelium will be thin which a

secondary manifestation is and mastication of the above teeth will allow

the enlargement, it fells bony.

The lesion may be radiopaque or radiolucent or mixed according to the

amount of osteoid that will be formed within the lesion; if it has more

bone radiobaque but if it has less bone then it will be radiolucent.

Swelling Pain, toothache because the tumor may press on the nerves and it

will resorb teeth.

Loose or displaced teeth Bleeding Paresthesia because of pressure on nerves



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*** Sun-ray pattern: due to formation of bony trabeculae in perpendicular

angle to the bone .It is present only in 25% of all patients and it may present in

other lesions.

**Not unique to osteosarcoma**

Early signs: localized symmetrical widening

of PDL because it is easy to go through them.

Treatment: Surgery, radiation thereby or

chemotherapy.

***If the whole lesion was like this

then it will appear radiolucent.

End of part two



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Part three : By Ali Al-Qudsi

Chondrosarcoma is a tumor of chondroblasts (cartiallage producing cells),

classified as a primary bone tumor, due to remnants of cartilage in the jaw

(Mandible = Head of the condyle / Maxilla = Close to the anterior part of the

maxilla).

Product of chondrobalsts = Chondroid

Chondrosarcoma = Malignant, Chondroma = Benign.

The more common of the two is the malignant form (Chondrosarcoma).

The chondroid matrix appearance

is not completely pink/eosophillic

it appears a mix of eosniphillic

and basophilic, the

chondoroblasts themselves are

found in their lacuna but they are

Pleomorphic (varying size),

Mulit-loculated, can Be Bi-

nucleated, (highly cellular &

Contains plump cells).

The appearance of Chondroma (benign form) closely resembles that of the

chondrosarcoma except a few differences, mainly No bi-nucleation, no

Hyperchromatism and minimal pleomorphisim (picture A in next page )



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Chondrosarcomas/Chondromas can appear

radiographically as radio-opaque, radio-

lucent or mixed depending on the amountof chondroids found in the lesion. These

chondroids may later ossify (turn into

bone) with time which makes it difficult to differentiate between Chondrosarcomas

and Osteosarchomas microscopically (each has a different treatment, therefore it‟s

critical to differentiate between the two.

Mandibular lesions have a better prognosis (less dangerous)

Chondrosarcomas are less aggressive than other sarcomas (slower growth

rate).

Plasma cells (found in bone marrow) may become cancerous leading to

a condition known as multiple myelomas (malignant tumor/neoplasm of plasma

cells), may be present as a Single

lesion/Multiple lesions. Multiple myeloma ismost common in elderly patients, a common

symptom of multiple myelomas is sever bone

pain, upon radiographic investigation the

patients skull appears to have „a punched out

appearance’ (present as well defined well

rounded radiolucencies). Multiple myeloma may

affect several bones (skull, vertebral column,

mandible and other bones).

The product of plasma cells are immunoglobulins (IgG, IgA, IgE…)

A single lesion of defected plasma cells is called Plasma-Cytoma



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Upon protein investigation of blood there will be a peak/spike in one of the

blood proteins due to monoclonal proliferation of the plasma cells. This

protein is the M Spike/Para-protein (M in relation to myeloma) this M

spike represents the increase in the number of IGs.

Malignant tumors are usually accompanied by rapid

growth and destruction accumulating in both bone and

soft tissue. Radiographically the lesions appear Ill-

Defined leading to a radiographical feature called

„floating in air teeth’ (teeth appear to be unsupported

at all- very common in Langerhan Cell Disease) due

to the destruction in bone (the tooth is only supported

by abnormal soft tissue- hardly any bone left).

The most commonly affected bones are the

Skull, Vertebrae, Sternum and Pelvis; however

it‟s possible that the only clinical manifestation

is lower back pain.

Electrophoresis to search for „M Spike Protein‟

Bence-Jones Proteins- light protein chains that may leak out in the urine

(present in 50% of the cases)

Blood may contain Increase in Calcium (due to increased bone resorption)

Amyloidosis (Protein presence in tissue of chronic diseases) leads to

Macroglossia or swelling.

Sharply demarcated punched out radiolucencies (diploe of the skulls are

evident- lost in Paget‟s disease)



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Within the bone you can see sheets of malignant

plasma cells. Characteristics of these malignant

plasma cells are: Pleomorphism,hyperchromatism and Monoclonal (Use

Kappa/Lambda test to see if they are producing

similar chains or not — type of diagnostic test), if

the lesion is reactive and produces different types

of chains then it is classified as polyclonal.

End of part three

End of the lecture

done by : Enas salameh , Ali Alqudsi and Osama Yousef

Script # 12 .. Bone disorders 4

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