script #13, bone disorders 5

8/3/2019 Script #13, Bone disorders 5

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DISORDERS OF BONEThe last lecture about bone disorders .. Be Happy :)

We talked last lecture about Osteosarcoma , Chondrosarcoma and Multiple Myeloma and now we

are gonna talk about Langerhans Cell Histiocytosis

A) Langerhans Cell Histiocytosis--->

Langerhans cells: are antigen presenting cells (APC) present in epidermis, lymph

nodes, mucosa and bone marrow

They are so important for the immune system >> they engulf the particles (

antigens ) and present them using MHC ( Major Histocompatibility Complex ) to the

lymphocytes and then the lymphocytes will induce adaptive immunity which is a

stronger immunity

Langerhans Cell Histiocytosis is a rare disease involving colonal proliferation of the

Langerhans cells ( histocytosis ) >> it's a destructive lesion


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Because they present in the bone marrow they may get monoclonal proliferation

and any thing proliferate monoclonally it is not reactive it is neoplastic , but if any

proliferation was polyclonal it will be reactive not neoplastic

Monoclonal -- > Neoplastic -- > Langerhans cell histocytosis Polyclonal -- > Reactive

Langerhans cells increase in number but they are malignant >> they are not

following the cell cycle control proteins >> so they will proliferate for ever and they will

acquire more mutation >> more aggressive >> more invasive & more malignant

behavior

Langerhans Cell Histiocytosis

Three clinical forms >>

Classified into three forms due to the extension :

1st

form single lesion called solitary , 2nd

form multifocal the bone is involved in addition

to other organs , the 3rd

form the bone is involved in addition to the skin and other

organs

1) Solitary eosinophilic granuloma of bone : called eosinophilic due to present of

eosinophills mixed with langerhans cells

Usually single lesion >> Unifocal >> in the bone , soft tissue , mandible , maxilla orgingiva

2) Multifocal: bone and other organs ( soft tissue )

called Hand Schuller Christian syndrome (triad) where there is involvement of

the orbit and pituitary gland giving skull defects , exophthalmus of the eyes and


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diabetes insipidus ( due to the involvement of the pituitary gland , all the hormones

will be affected or involved leading to DI )

3) Disseminated histiocytosis ( multi-organ disease ) >> not combatable with life >>called Letterer Siewe disease

maybe chronic or acute

this disease is usually Fatal

the multifocal form here usually involves the bone and some other organs but not as

extensive and disseminated as the 3rd form which is >>>> occurs mainly in infants and

childrens under 2 years of age and have a high mortality


Clinical features

1) It is ill defined , it destroyed the teeth by root resorbtion >

perforate the cortex

2) resorbe the bone >> loosening of teeth

3) Radiographically: floating in air ( important )

4) May simulate a periapical lesion

5) gingival ulceration, or enlargement

Here there is a periapical lesion that doesn't really make sense >> the tooth (1) here is root

canal treated and here (2) is vital having nothing and here (3) is vital too >> so why we have

a big radiolucent area which is ill defined and the teeth maybe loos ?? >> we will think about

neoplastic lesions >> we will take a biopsy and the lesion will turn aout to be langerhans cell

histocytosis


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Histopathology

How langerhans cells look like ??They have kidney shaped nucleus and abundant cytoplasm ( plenty of cytoplasm )

InLangerhans Cell Histiocytosis Proliferation of Langerhans cells accompanied by:eosinophils, plasma cells and multinucleated giant cells

Electron microscope: Birbek granules

Immunohistochemistry: surface Ag: CD1-a

u know that some cells have antigens on there surfaces that distinguish them from

others like CD3 on the T cells CD20 on the B cells but on the langerhans cells the

antigen that we look for is the CD1-a >> so if u think that this lesion is langerhans cell

hystocytosis u have to ask for a special stain for the CD1-a antigen if it is positive then

it is positive to the disease if not it is not

>> The lesion is focal sometimes

Here the patient has good healthy teeth but

focally there is destroyed periodontium after

radiograph ( look at the radiograph in slide#50

or in the previous page in the lecture ) there was

a radiolucent region , ill-defined , destroying the

bone and resorbing the root >> after biopsy the

lesion turned to be langerhans cell histocytosis


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In the picture above

Arrow1 >> big cell it looks like the macrophage , it is big it has plenty of cytoplasm

(pink) and big nucleus it is oval to kidney shaped ( and may be indented nuclei ) and

the cells are polymorphic >> variation in the size and shape of the nuclei and stain

characteristic

Arrow2 >> eosinophil with pink cytoplasm >> they looks like neutrophil but the

cytoplasm is pink and the neutrophil is having mutilobulated nucleus

The eosinophils are not neaoplastic , the langerhans cells which are neoplastic and

proliferate monoclonally


Treatment

1) Curettage

2) Radiotherapy

3) Intralesional injection with steroid it may work


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A) Hemangioma of Bone--->

Sometimes is considered as developmental changes not a true neoplasm but

some of the books is still consider hemangioma as benign tumor of blood vessels

Hemangioma may occur in any location where blood vessels are May occur inside the bone , called >> central hemangioma of bone and this type

usually give us >> Multilocular radiolucency bcz it extents within all marrow spaces

and start to expand

Even there is expansion but there still bone trabeculae >> but the trabeculation is

relatively more radiolucent If the lesion is aspirated it will reveal fresh blood and this will confirm the

diagnose

Usually it is cavernous type >>

What is the difference between cavernous type and capillary type ??

The size of the blood vessels ( capillary > small blood vessels , cavernous > big

dilated blood vessels )

This is Multilocular radiolucency extents within all marrow spaces in the body of

the mandible


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This is Multilocular radiolucency or honey cell in the anterior region of the

maxilla >> it's not malignant bcz I don't see root resorption >> the root are pushed

away which means this lesion is slowly growing giving time for root to be displaced

After biopsy u will see bone marrow trabeculation>> (pink)

And in between there are lots of dilated blood

vessels and they are mainly of the cavernous type


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Now we gonna talk about tumors of bone , we finished reactive conditions ,

inflammation and unknown etiology and now we will continue with tumors of bone ..

Ossifying FibromaDr talked about it quickly and nothing new .. every thing is written in the 2

ndlec of

bone but I put her discussion about pictures as revision

This is a general picture for fibro-ossious

lesions so we can't determine it is

ossifying fibroma or any other fibro

osseous lesion

1>> is bone trabeculea and it is vital bone

bcz it contains osteocytes inside lacunae

But when we look at the mass we

will say >> this is ossifying fibroma

bcz it is one piece and encapsulated


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Metastatic TumorsBone metastasis > soft tissue

Mandible>maxilla

Most common primary tumors that metastasize >>1) Carcinoma: breast, bronchus, kidney

2) Prostate, lungClinical features- pain, loose teeth, swelling, parasthesia, asymptomtic

breast and prostate tumors are osteoblasticbut,Most are osteolytic-

I can see in the picture one of the ID

canal borders so I will say >> this lesion

isn't below the ID canal >> it isn't staphne

bone defect >> it has to be biopsied

Now after biopsy it turned to be metastatic

tumor

This island is malignant glandular like

tissue or carcinoma >> metastasizing

from a primary tumor ( from kidney ,

lung etc )


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this is a destructive lesion in the body and

the angle of the mandible

This is the histopathology for the previous

radiograph >> there is a glandular (bcz

there is space in the center ) collections

of malignant cells ( they are dark in

color) >> so this is metastatic carcinoma

How do we know that this is carcinoma??

Epethilial cells usually like to be cohesive

and form islands ( bcz they have

dismosoms and hemidismosoms

This is a Metastatic disease >>

Here we have condensation of bone ..

U may say this is bone scar , u may say this

is metastatic osteoblastic tumor or

condensing ostitis

But later on it will turn to be metastatic

disease


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script #13, bone disorders 5

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