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Pseudosoft tissue

Cyst
By

Dr . Wael Mohamed Swelam
Dr. Wael Swelam

Monday, January 20, 2014
References

Dr. Wael Swelam

Monday, January 20, 2014
pseudo cyst ╳ true cyst
Type
Lining

True cyst

Pseudo cyst

The wall of a true cyst consists of a The wall of a pseudocyst consists of
clearly defined epithelial cell layer granulation and/or fibrous tissue

(origin: odontogenic X non odontogenic)

(which is present secondary to inflammation)

Classification of Pseudo cysts

Traumatic

Aneurysmal
Dr. Wael Swelam

Traumatic

Developmental

Static bone cyst

bone
marrow
defect

Monday, January 20, 2014
1. Aneurysmal bone cyst
Etiology and pathogenesis:
1. Traumatic event result in an area of haemorrhage that maintain connection
with the original with the disrupted feeding vessels. Subsequently giant cell
granuloma-like can develop after loss of connection with the original
vascular source
2. Frequently develops secondary within another lesion of bone as a result of
disrupted vascular dynamics in pre-existing intrabony lesion
ex. Central giant cell tumors

Dr. Wael Swelam

Monday, January 20, 2014
Aneurysmal bone cyst
Age :
 Young

adults < 30 Years

Location:
 Shaft

of long bones

 Vertebral
 2%

column

Jaw bone; posterior mandibular is more common

Sex : No predilection
Manifestations:
 Rapidly
 Painful

Dr. Wael Swelam

growing swelling
frequently with parathesia
Monday, January 20, 2014
Aneurysmal bone cyst
 Radiographic features:





Malocclusion
Mobility
Migration
Root resorption

 Maxillary lesions:


Nasal manifestations






Bulging into adjacent sinus
Nasal obstruction
Nasal bleeding

Optical manifestations



Proptosis
Diplopia

Dr. Wael Swelam

Monday, January 20, 2014
Aneurysmal bone cyst
 Surgical Histopathology:


At operation
Intact periosteum
B. Shell cortex often with perforation
C. After removal of A & B dark venous blood wells up
A.



Surgeon impression:
 Blood

soaked sponge

Histopathological features:
 Spaces

of varying size
 Filled with blood
 Surrounded by cellular fibroblastic tissue
 Wall contain multinucleated giant cells and osteoid tissue
 Might be associated with other pathosis mostly fibrous dysplasia
Dr. Wael Swelam

Monday, January 20, 2014
Traumatic bone cyst
Etiology and pathogenesis:
1. Trauma-hemorrhage theory:
Traumatic event that is insufficient to cause bone fracture result in an
intraosseous hematoma. If hematoma doesn’t undergo organization and
repair the clot breaks down (liquefy) leaving an empty bony cavity.
2. Altered bone metabolism theory:
Inability to of interstitial fluid to exit the bone because of
* Inadequate venous drainage
* Local disturbance of in bone growth
* Ischemic marrow necrosis
Result in Osteolysis
Dr. Wael Swelam

Monday, January 20, 2014
Traumatic bone cyst
Age :
 10-20

Years

Location:
 Essentially
 More
 Sex

restricted to the mandible

common in premolar – molar region

: 60% ♂

Manifestations:
 Asymptomatic
 20%

and usually discovered accidentally

might have painless swelling

 Associated with vital teeth
 At

operation the lesion appear as an empty cavity

Dr. Wael Swelam

Monday, January 20, 2014
Traumatic bone cyst
Radiographic features :
 Well

delineated, radiolucent defect

 Unilocular,

or Multilocular

 When

several teeth are involved in the lesion, the
defect shows domelike projections that scallop upward
between the roots, NO root resorption of related teeth

Location:
 Essentially
 More
 Sex

restricted to the mandible

common in premolar – molar region

: 60% ♂

Dr. Wael Swelam

Monday, January 20, 2014
Traumatic bone cyst
Histopathological features:






Empty spaces of varying size
Surrounded by thin band of vascular fibrous connective tissue cellular
fibroblastic tissue
Wall occasionally contain multinucleated giant cells and osteoid tissue
Might be associated with other pathosis mostly fibrous dysplasia

Dr. Wael Swelam

Monday, January 20, 2014
Static bone cyst
Stafne’s bone defect
Definition:
Lingual mandibular Salivary Gland Depression:
A developmental concavity of the lingual cortex of the mandible, usually in the
third molar area, that forms around an accessory lateral lobe of submandibular
gland and has the radiographic appearance of a well-circumscribed cystic
lesion within the bone, usually below the inferior alveolar canal.
canal
Etiology and pathogenesis:
The pathogenesis is unknown exactly
1. Entrapment of salivary gland tissue during the development of the mandible
2. Lingual cortical erosion from hyperplastic salivary gland tissue, both
demographic and anatomic findings are consistent with this hypothesis
Dr. Wael Swelam

Monday, January 20, 2014
Stafne’s bone defect
Age :


Adults

Sex:
 80-90%

♂

 Clinical features:
 Anterior

defects are related to sublingual SG

 Posterior

defects are related to submandibular SG

 Might

interrupt the continuity of the inferior border of
the mandible

 Rarely;

increase in size over time which indicate
that these lesions are nor congenital

Dr. Wael Swelam

Monday, January 20, 2014
Osteoporotic bone marrow defect
Etiology
 Abnormal
 Residual
 Focus

healing following tooth extraction

remnants of fetal marrow

of extramedullary haematopoiesis

Sex
 Female

70%

Clinical features
 Site:

Angle/ posterior mandible

Histopathological features:
 Predominance

of haematopoietic cells with fewer fat cells

 Lymphoid

aggregates within cellular marrow &
megakaryocytes

Dr. Wael Swelam

Monday, January 20, 2014
Dr. Wael Swelam

Monday, January 20, 2014
Embryological review

Development of pharyngeal pouches

Development of Tongue

Dr. Wael Swelam

Monday, January 20, 2014
Branchial cyst
Cervical lymphoepithelial cyst
Etiology and pathogenesis

Fusional lesion hypothesis






Incomplete obliteration of the fetal branchial arches, i.e. the lack of
degeneration of the cervical sinus created by the growth of the second arch
over the third and fourth arches is the proposed cause.
The third and fourth arches thus overlaid by the second arch persist as small
pockets with their ectodermal epithelium.
These pockets usually fill in during fetal development; however, when they
do not, cysts, sinuses and fistulas.

Dr. Wael Swelam

Monday, January 20, 2014
Branchial cyst
Cervical lymphoepithelial cyst
Clinical features
 Age

20:40 Y
 Usually unilateral, rarely bilateral
 Soft, fluctuant, asymptomatic, enlargement
 Along anterior margin of sternomastoid
 Some lesions appear as sinus or fistulae on the skin

Histological features
90% are lined by stratified squamous epithelium
may/may not be keratinized
 Cyst wall typically contain lymphoid tissue with
germinal centers


Dr. Wael Swelam

Monday, January 20, 2014
Oral Lymphoepithelial cyst
Cystic changes in entrapped lymph node epithelial islands

Etiology:
 Epithelial invagination into tonsillar
tissue, result in blind pouches or tonsillar
crypts
Clinical features:
 Small submucosal nodule covered by
normal overlying mucosa.
Microscopic features:
 Epithelial lined space with lymphoid
tissue in the surrounding c.t. wall.

Dr. Wael Swelam

Monday, January 20, 2014
Thyroid gland development

Dr. Wael Swelam

Monday, January 20, 2014
Thyroglossal tract cyst
 Most common 75% of developmental cyst of the neck
 As thyroid anlage grow downward from foramen caecum to its

permanent location in the neck. Residual epithelial elements
along this pathway may give rise to cysts

Dr. Wael Swelam

Monday, January 20, 2014
Thyroglossal tract cyst








Mostly occur in midline, Below the level of hyoid bone
2% occur within the tongue itself (lingual thyroid nodule)
Sinus tract formation if secondary infected
Rarely undergo malignant transformation
50% occur before 20 years
No sex predilection
Painless, fluctuant, movable swelling
 Retract on swallowing if it maintain an attachment to hyoid
 Retract on tongue movement if it maintain attachment with tongue

Histopathological features:
Cyst lining with ciliated or columnar epithelial lining
Thyroid tissue might be seen within CT

Dr. Wael Swelam

Monday, January 20, 2014
Dermoid cyst
 Developmental cystic malformation,
 Due to entrapment of totipotent blastomeres, which can

produce derivatives of all three germ layers
 Oral lesions affect anterior portion of oral cavity,
 Appear on midline
 If develop above geniohyoid ms sublingual swelling will

displace tongue = difficulty in eating, speaking, berating
 If develop below geniohyoid ms will result in submental

swelling ‘double chin appearance’
Teratoid cyst
is a term used to describe a cystic form of teratoma that
contain a variety of germ layer derivatives:


Skin appendages ex. Hair follicle, sebaceous gland, sweet gland



Connective tissue elements ex. Muscle, blood vessel, bone



Endodermal structures ex. GIT lining

Dr. Wael Swelam

Monday, January 20, 2014
Epidermoid cyst
 Usually follow localized inflammation of the hair follicle and

represent non neoplastic proliferation of epithelium resulting from
healing process
 Oral lesions are very rare, the lesion mainly affect skin

Clinical features





Common in acne-prone areas of the head and neck,
Unusual before puberty
Usually associated with Gardner Syndrome
Appear as nodular fluctuant subcutaneous lesion

Histopathological features





Cavity lined by stratified squamous epithelium,
Well developed granular cell layer
Lumen filled with orthokeratin
Prominent inflammatory reaction including multinucleated giant cells

Dr. Wael Swelam

Monday, January 20, 2014
Dr. Wael Swelam

Monday, January 20, 2014

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Pseudo cyst

  • 1. Pseudosoft tissue Cyst By Dr . Wael Mohamed Swelam Dr. Wael Swelam Monday, January 20, 2014
  • 3. pseudo cyst ╳ true cyst Type Lining True cyst Pseudo cyst The wall of a true cyst consists of a The wall of a pseudocyst consists of clearly defined epithelial cell layer granulation and/or fibrous tissue (origin: odontogenic X non odontogenic) (which is present secondary to inflammation) Classification of Pseudo cysts Traumatic Aneurysmal Dr. Wael Swelam Traumatic Developmental Static bone cyst bone marrow defect Monday, January 20, 2014
  • 4. 1. Aneurysmal bone cyst Etiology and pathogenesis: 1. Traumatic event result in an area of haemorrhage that maintain connection with the original with the disrupted feeding vessels. Subsequently giant cell granuloma-like can develop after loss of connection with the original vascular source 2. Frequently develops secondary within another lesion of bone as a result of disrupted vascular dynamics in pre-existing intrabony lesion ex. Central giant cell tumors Dr. Wael Swelam Monday, January 20, 2014
  • 5. Aneurysmal bone cyst Age :  Young adults < 30 Years Location:  Shaft of long bones  Vertebral  2% column Jaw bone; posterior mandibular is more common Sex : No predilection Manifestations:  Rapidly  Painful Dr. Wael Swelam growing swelling frequently with parathesia Monday, January 20, 2014
  • 6. Aneurysmal bone cyst  Radiographic features:     Malocclusion Mobility Migration Root resorption  Maxillary lesions:  Nasal manifestations     Bulging into adjacent sinus Nasal obstruction Nasal bleeding Optical manifestations   Proptosis Diplopia Dr. Wael Swelam Monday, January 20, 2014
  • 7. Aneurysmal bone cyst  Surgical Histopathology:  At operation Intact periosteum B. Shell cortex often with perforation C. After removal of A & B dark venous blood wells up A.  Surgeon impression:  Blood soaked sponge Histopathological features:  Spaces of varying size  Filled with blood  Surrounded by cellular fibroblastic tissue  Wall contain multinucleated giant cells and osteoid tissue  Might be associated with other pathosis mostly fibrous dysplasia Dr. Wael Swelam Monday, January 20, 2014
  • 8. Traumatic bone cyst Etiology and pathogenesis: 1. Trauma-hemorrhage theory: Traumatic event that is insufficient to cause bone fracture result in an intraosseous hematoma. If hematoma doesn’t undergo organization and repair the clot breaks down (liquefy) leaving an empty bony cavity. 2. Altered bone metabolism theory: Inability to of interstitial fluid to exit the bone because of * Inadequate venous drainage * Local disturbance of in bone growth * Ischemic marrow necrosis Result in Osteolysis Dr. Wael Swelam Monday, January 20, 2014
  • 9. Traumatic bone cyst Age :  10-20 Years Location:  Essentially  More  Sex restricted to the mandible common in premolar – molar region : 60% ♂ Manifestations:  Asymptomatic  20% and usually discovered accidentally might have painless swelling  Associated with vital teeth  At operation the lesion appear as an empty cavity Dr. Wael Swelam Monday, January 20, 2014
  • 10. Traumatic bone cyst Radiographic features :  Well delineated, radiolucent defect  Unilocular, or Multilocular  When several teeth are involved in the lesion, the defect shows domelike projections that scallop upward between the roots, NO root resorption of related teeth Location:  Essentially  More  Sex restricted to the mandible common in premolar – molar region : 60% ♂ Dr. Wael Swelam Monday, January 20, 2014
  • 11. Traumatic bone cyst Histopathological features:     Empty spaces of varying size Surrounded by thin band of vascular fibrous connective tissue cellular fibroblastic tissue Wall occasionally contain multinucleated giant cells and osteoid tissue Might be associated with other pathosis mostly fibrous dysplasia Dr. Wael Swelam Monday, January 20, 2014
  • 12. Static bone cyst Stafne’s bone defect Definition: Lingual mandibular Salivary Gland Depression: A developmental concavity of the lingual cortex of the mandible, usually in the third molar area, that forms around an accessory lateral lobe of submandibular gland and has the radiographic appearance of a well-circumscribed cystic lesion within the bone, usually below the inferior alveolar canal. canal Etiology and pathogenesis: The pathogenesis is unknown exactly 1. Entrapment of salivary gland tissue during the development of the mandible 2. Lingual cortical erosion from hyperplastic salivary gland tissue, both demographic and anatomic findings are consistent with this hypothesis Dr. Wael Swelam Monday, January 20, 2014
  • 13. Stafne’s bone defect Age :  Adults Sex:  80-90% ♂  Clinical features:  Anterior defects are related to sublingual SG  Posterior defects are related to submandibular SG  Might interrupt the continuity of the inferior border of the mandible  Rarely; increase in size over time which indicate that these lesions are nor congenital Dr. Wael Swelam Monday, January 20, 2014
  • 14. Osteoporotic bone marrow defect Etiology  Abnormal  Residual  Focus healing following tooth extraction remnants of fetal marrow of extramedullary haematopoiesis Sex  Female 70% Clinical features  Site: Angle/ posterior mandible Histopathological features:  Predominance of haematopoietic cells with fewer fat cells  Lymphoid aggregates within cellular marrow & megakaryocytes Dr. Wael Swelam Monday, January 20, 2014
  • 15. Dr. Wael Swelam Monday, January 20, 2014
  • 16. Embryological review Development of pharyngeal pouches Development of Tongue Dr. Wael Swelam Monday, January 20, 2014
  • 17. Branchial cyst Cervical lymphoepithelial cyst Etiology and pathogenesis Fusional lesion hypothesis    Incomplete obliteration of the fetal branchial arches, i.e. the lack of degeneration of the cervical sinus created by the growth of the second arch over the third and fourth arches is the proposed cause. The third and fourth arches thus overlaid by the second arch persist as small pockets with their ectodermal epithelium. These pockets usually fill in during fetal development; however, when they do not, cysts, sinuses and fistulas. Dr. Wael Swelam Monday, January 20, 2014
  • 18. Branchial cyst Cervical lymphoepithelial cyst Clinical features  Age 20:40 Y  Usually unilateral, rarely bilateral  Soft, fluctuant, asymptomatic, enlargement  Along anterior margin of sternomastoid  Some lesions appear as sinus or fistulae on the skin Histological features 90% are lined by stratified squamous epithelium may/may not be keratinized  Cyst wall typically contain lymphoid tissue with germinal centers  Dr. Wael Swelam Monday, January 20, 2014
  • 19. Oral Lymphoepithelial cyst Cystic changes in entrapped lymph node epithelial islands Etiology:  Epithelial invagination into tonsillar tissue, result in blind pouches or tonsillar crypts Clinical features:  Small submucosal nodule covered by normal overlying mucosa. Microscopic features:  Epithelial lined space with lymphoid tissue in the surrounding c.t. wall. Dr. Wael Swelam Monday, January 20, 2014
  • 20. Thyroid gland development Dr. Wael Swelam Monday, January 20, 2014
  • 21. Thyroglossal tract cyst  Most common 75% of developmental cyst of the neck  As thyroid anlage grow downward from foramen caecum to its permanent location in the neck. Residual epithelial elements along this pathway may give rise to cysts Dr. Wael Swelam Monday, January 20, 2014
  • 22. Thyroglossal tract cyst        Mostly occur in midline, Below the level of hyoid bone 2% occur within the tongue itself (lingual thyroid nodule) Sinus tract formation if secondary infected Rarely undergo malignant transformation 50% occur before 20 years No sex predilection Painless, fluctuant, movable swelling  Retract on swallowing if it maintain an attachment to hyoid  Retract on tongue movement if it maintain attachment with tongue Histopathological features: Cyst lining with ciliated or columnar epithelial lining Thyroid tissue might be seen within CT Dr. Wael Swelam Monday, January 20, 2014
  • 23. Dermoid cyst  Developmental cystic malformation,  Due to entrapment of totipotent blastomeres, which can produce derivatives of all three germ layers  Oral lesions affect anterior portion of oral cavity,  Appear on midline  If develop above geniohyoid ms sublingual swelling will displace tongue = difficulty in eating, speaking, berating  If develop below geniohyoid ms will result in submental swelling ‘double chin appearance’ Teratoid cyst is a term used to describe a cystic form of teratoma that contain a variety of germ layer derivatives:  Skin appendages ex. Hair follicle, sebaceous gland, sweet gland  Connective tissue elements ex. Muscle, blood vessel, bone  Endodermal structures ex. GIT lining Dr. Wael Swelam Monday, January 20, 2014
  • 24. Epidermoid cyst  Usually follow localized inflammation of the hair follicle and represent non neoplastic proliferation of epithelium resulting from healing process  Oral lesions are very rare, the lesion mainly affect skin Clinical features     Common in acne-prone areas of the head and neck, Unusual before puberty Usually associated with Gardner Syndrome Appear as nodular fluctuant subcutaneous lesion Histopathological features     Cavity lined by stratified squamous epithelium, Well developed granular cell layer Lumen filled with orthokeratin Prominent inflammatory reaction including multinucleated giant cells Dr. Wael Swelam Monday, January 20, 2014
  • 25. Dr. Wael Swelam Monday, January 20, 2014