Características de los proyectos candidatos

9 CRITERIOS PARA LA FORMULACION DEL PLAN

10.6 Características de los proyectos candidatos

1 CYSTS

Cyst

• A pathologic cavity having fluid, semi fluid or gaseous contents and which is not created by accumulation of pus

• Derived from Greek word ‘Kystis Sac’

Cyst Parts

1. Cyst lumen/central cavity 2. Cyst lining – epithelium

3. Cyst capsule at periphery – connective tissue wall

CLASSIFICATION

• Presence/absence of Epithelial lining 1. True cyst

2. Pseudocyst/false cyst – Pathologic cavities not lined by epithelium

CLASSIFICATION (SHEAR’S) Cysts of the Jaw

A. Epithelium Lined Cysts I. Developmental origin

1. Odontogenic

i. Gingival cysts of infant ii. Gingival cysts of adult iii. Odontogenic keratocyst iv. Dentigerous cyst v. Eruption cyst

vi. Developmental lateral periodontal cyst

vii. Botryoid odontogenic cyst viii. Glandular odontogenic cyst ix. Calcifying odontogenic cyst

2. Non-odontogenic

i. Mid palatal raphe cyst of infants ii. Nasopalatine duct cyst

iii. Nasolabial cyst

II. Inflammatory origin

i. Radicular cyst, apical and lateral ii. Residual cyst

iii. Paradental cyst and Juvenile Paradental cyst

iv. Inflammatory collateral cyst

B. Non-Epithelial Cysts 1. Solitary bone cyst 2. Aneurismal bone cyst

Cysts associated with the Maxillary Antrum 1. Mucocele

2. Retention cyst 3. Pseudo cyst

4. Post operative maxillary cyst

Cysts of the soft tissues of Mouth, Face and Neck 1. Dermoid and epidermoid cyst

2. Lymphoepithelial (bronchial) cyst 3. Thyroglossal duct cyst

4. Anterior median lingual cyst (intra lingual cyst of foregut origin)

5. Oral cysts with gastric or intestinal epithelium (oral alimentary tract)

6. Cystic hygroma 7. Nasopharyngeal cyst 8. Thymic cyst

9. Cysts of the salivary glands: Mucous extravasation cyst, Mucous retention cyst, Ranula, Polycystic (dysgenetic) disease of parotid

10. Parasitic cysts: Hydatid cyst, Cysticercus cellulosae, Trichinosis

CLASSIFICATION BY TISSUE OF ORIGIN Derived from Rests of Malassez

1. Periapical cyst 2. Residual cyst

Derived from Reduced Enamel Epithelium 1. Dentigerous cyst

2. Eruption cyst

Derived from dental lamina (Rests of Serre) 1. Odontogenic keratocyst

2. Gingival cyst of new born 3. Gingival cyst of adult 4. Lateral periodontal cyst 5. Glandular odontogenic cyst

MECHANISM OF CYST DEVELOPMENT

• The common feature of all cysts is the stimulation of residual developmental epithelial cells, leading to proliferation but not invasion of adjacent tissues.

• The epithelial rests proliferate into a solid mass of epithelial cells. As the mass enlarges, the epithelial cells in the center become positioned further from the blood supply at the periphery of the mass.

• At some point, the cells at the center become too far removed from the nearest blood vessel

to survive by nutritional diffusion. They die, creating a lumen. Their intracellular products make the lumen hypertonic, which transudates fluid into the lumen. This in turn creates a hydrostatic pressure, producing bone resorption, clinical expansion, and sometimes mild paresthesia or pain.

• As additional epithelial cells die off and are sloughed into the lumen, their contents perpetuate the hypertonic state and the hydrostatic pressure.

• The cell membranes and nuclear membranes of these sloughed cells are high in cholesterol, hence the common finding of cholesterol clefts in the lumen or even in the walls of many cysts.

• As the cyst enlarges, it compresses surrounding connective tissue into a connective tissue wall.

• The epithelial lining matures and develops a basement membrane.

• The cyst lining continues to proliferate, thus causing the cyst to enlarge until it is removed (enucleation); the proliferating cells are communicated into the oral cavity or an external surface so as to break the proliferation-hydrostatic pressure cycle (marsupialization), or the inciting cytokines are removed (via tooth removal or root canal therapy in radicular

2. Hydrostatic enlargement 3. Bone resorbing factors

1. Mural growth

• Growth occurring in the wall of cyst

• Occurs by peripheral cell division/

accumulation of cellular contents

Peripheral cell division

Stimulus acts as an irritant to lining epithelium active cell division peripheral growth of cyst

Proliferating epithelium inductive influence on underlying CT proliferation & expansion of CT

Mitotic values of epithelial lining reflect cyst growth

Higher mitotic value = greater growth potential of cyst & vice versa

o Highest for OKC – 8 o Least for DC – 0.6 o Radicular cyst – 4.6 o Nasopalatine cyst – 2.3 o Inflammatory collateral cyst – 2 o Residual cyst – 1

Mitotic activity not equated to the number of mitotic figs

Hence other factors play a major role rather than the mitotic activity alone

Accumulation of cellular contents

Accumulation of mural keratin squames in lumen enlargement

Cyst volume increases by proliferation of cyst lining at active cellular sites & shedding of cells into lumen

Local areas of increased cell division

finger like epithelial projections in turn CT proliferation expansion of cyst

Growth of cyst due to this factor occurs mainly along medullary bone with little cortical expansion

2. Hydrostatic enlargement

• Distension of cyst wall by fluid that accumulates by one / more processes

• Distension depends on

Vascular pressure

Collagen fibers

• Average intra luminal pressure

Radicular cyst – 70 cm of water

Transudation & exudation

Dialysis

1. Secretion

Very few secretory products

Active secretion by secretory cells in epithelium is very less

40% of DC – Goblet cells – mucous

High molecular weight GAGs o Products of normal

metabolic turnover /

ORAL PATHOLOGY Cysts of Oral Region

3

inflammatory degradative products of CT

o Enter lumen via altered permeability of lining epithelia

2% DC – epithelial lining cells keratinizing metaplasia contributes to keratin accumulation in cyst lumen

Plasma cells

o Secrete immunoglobulins o Reach the cyst lumen via

epithelial lining

2. Transudation & exudation

Cysts grow by accumulation of inflammatory transudates &

exudates – proven by examining the protein content & specific gravity

Total soluble Protein levels o Radicular cyst: 6.3 – 7.5

gms100 ml (rich in gamma globulins)

― High mol wt substances enter via altered vascular permeability - suggest that they are

other high mol wt substances – fibrin & cholesterol also found in cyst fluid – products of haemorrhage o Growth of both Dentigerous

cyst & Radicular cyst - Unicentric due to hydrostatic forces

3. Dialysis

Refers to accumulation of fluid in the cyst lumen due to difference in the osmolarity of the cyst fluid and serum with cyst fluid having a higher osmolarity

o Desquamated epithelial cells o Fibrin

• Confirms the cystic nature

• Wide bore needle with 5-10ml syringe

• Clear pale straw colored fluid Dentigerous, periodontal & periapical cyst

Glistening crystals (cholesterol crystals) periapical cyst

• Cheesy creamy white material – masses of desquamated keratin Odontogenic keratocyst

• Golden yellow fluid – clots on standing Solitary bone cyst

• Fresh blood solitary bone cyst / ABC / vascular tumours?? / AV aneurysms??

• Opaque dark brown Haemorrhage in Cyst

• Greenish thick, viscous fluid with foul odor (pus) Infected cyst

• Failure to aspirate solid tumour

BIOCHEMICAL EVALUATION OF FLUID

• Levels of soluble proteins estimated by electrophoresis

• > 4.89/100ml – Inflammatory / non keratinizing cyst

• < 4.89/100ml – Keratinizing Cyst

PSEUDOCYSTS

• Pseudocysts are pathological cavity or an abnormal or dilated space, resembling a cyst but not lined by epithelium.

• They may contain fluid or sometimes tissue.

Pseudocysts of jaws Pseudocysts of soft tissue Aneurysmal bone cyst

/ cavity Antral Pseudocyst

Solitary bone cyst Mucous extravasation cyst

Stafne’s bone cavity Intra-oral lymphothelial cyst

Focal osteoporotic bone marrow defect

Parasitic cysts

• Hydatid cyst

• Cysticercus cellulosae Ganglion cyst ---

Common features of jaw Pseudocysts

• Largely asymptomatic

• Demarcated radiolucent appearance

• Diagnosed incidentally on radiographs

• Unclarified etiology/ pathogenesis

ORAL PATHOLOGY Cysts of Oral Region

PATHOGENESIS C/F R/F H/P ADDITIONAL NOTES

DENTIGEROUS CYST (Follicular cyst) (DC)

• Develops due to the fluid accumulation between reduced enamel epithelium and the enamel surface

• Encloses the crown of unerupted tooth at CEJ

• Young adult predilection

• M > F

• Most common sites: Mandibular and maxillary third molars, maxillary cuspids

• Mandibular 3^rd molar involvement may result in

‘hollowing-out’ of ramus

• May resemble an acute sinusitis or cellulites as it involves maxillary cuspid

• Mostly unilocular

• 3 types

1. Central Type: Crown is enveloped symmetrically.

2. Lateral Type: Dilatation of the follicle on one aspect of crown (common in mesioangular impaction of third molar)

3. Circumferential type: Entire tooth appears to be enveloped by cyst. Should be D/D from envelopmental variety of OKC. In DC – definite attachment at CEJ

• Central type is most common

• Normal follicular space is 3-4 mm

• Suspicion arises when the follicular space is > 5 mm

• Thin connective tissue wall with a thin layer of stratified squamous epithelial lining (2-4 cell thick)

• Presence of Rushton bodies (linear, curved, hyaline bodies, hematogenous origin)

• Presence of islands of odontogenic epithelium

• Metaplasia – mucous and ciliated cells

• Sebaceous cells in connective tissue & lymphoid follicles with germinal centers

• Dentigerous means ‘tooth bearing’.

(by Browne)

• Most common type of developmental odontogenic cyst

• Second most common cyst

• Initially associated with crown of an impacted, embedded or unerupted tooth

• May enclose complex compound odontome

• May involve supernumerary tooth

• Multiple or Bilateral cysts are associated with Cleidocranial dysplasia, Maroteaux – Lamy syndrome

• Complications of incomplete removal:

development of Ameloblastoma, Squamous cell carcinoma and Mucoepidermoid carcinoma

Aspirate

• Yellowish colored fluid

• Cholesterol crystals

• Soluble protein level: 5-7 gms/dl

Potential Complications

1. Development of an

Ameloblastoma either from the lining epithelium or from rests of odontogenic epithelium in the

wall of the cyst

2. Development of squamous cell carcinoma form the same to sources

3. Development of Mucoepidermoid carcinoma form the lining epithelium of dentigerous cyst which contains mucous secreting cells or cells with this potential 4. Squamous cell carcinoma ERUPTION CYST (Eruption Hematoma)

• Result of separation of dental follicle from around the crown of an erupting tooth that is within the soft tissues overlying the alveolar bone

• Usually associated with erupting succedaneous tooth / deciduous tooth

• Arises in an extra alveolar location Lies just beneath alveolar mucosa

• Children predilection

• M > F

• Most common site: anterior to first permanent molar

• Soft, translucent swelling on gingiva

• Surface trauma blood accumulation blue or purple color Eruption hematoma

• Soft tissue shadow • Keratinized stratified squamous epithelium of the overlying gingiva

• Dense connective tissue with inflammation

• Soft tissue analogue of Dentigerous cyst

•

GINGIVAL (ALVEOLAR) CYST OF NEW BORN

• Arise from remnants of dental lamina

• Bohn’s nodules – odontogenic origin

• Epstein’s pearls – non-odontogenic origin (epithelial inclusions in the fusion line between the palatal shelves &

nasal processes)

• Both have similar clinical &

• More common in infants

• Maxillary alveolus is more common than mandible

• Multiple raised nodules / small discrete white or cream colored

• Most of them under go involution and disappear, or rupture through the surface epithelium and exfoliates

• Buccal/lingual surface of

• Thin, flattened epithelial lining with a parakeratotic luminal surface

Synonyms

1. Dental lamina cyst of New born 2. Bohn’s nodules

3. Epstein’s pearls

histopathological features alveolar ridge – Bohn’s nodules

• Junction of hard & soft palate Epstein’s pearls

• Sources:

Heterotopic glandular tissue

Remnants of dental lamina or enamel organ

• 5^th – 6^th decade

• More common in mandibular canine & pre molar area

• Always found on f gingiva or alveolar mucosa

• Painless, dome like swelling

• May cause superficial

“cupping out” of alveolar bone (seen on excision only)

• Arise from remnants of dental Cysts of Oral Region

Bohn’s nodules soft palate –

GINGIVAL CYST OF ADULT

More common in mandibular canine & pre molar area Always found on facial gingiva or alveolar mucosa Painless, dome like swelling May cause superficial

“cupping out” of alveolar bone (seen on excision only)

• Similar features to Lateral Periodontal Cyst

• Thin, flattened epithelial lining with or without focal plaques that contain glycogen rich clear cells

LATERAL PERIODONTAL CYST

More common in Mandibular lateral incisor

• Round or tear drop shaped

well circumscribed

radiolucencies with a sclerotic margin, and measuring < 1 cm in diameter

• Located between the alveolar crest and the apex of the tooth Botryoid Odontogenic Cyst

Variant of LPC

Multilocular pattern

• Junction b/w epithelium flat / may show reteridges

• Nonkeratinised, cuboidal squamoid stratified epithelium

• 2-5 cell layers thick

• Clear cells with pyknotic nuclei rich in glycogen (originates from DL)

• Epithelial proliferation in localized areas project into lumen / underlying CT areas epithelial thickening

‘epithelial plaques’

• Plaques – pinch off from overlying epithelium & lie separately in CT

islands cystic degeneration Similar features to Lateral

Thin, flattened epithelial lining with or without focal plaques that

glycogen rich clear cells

• Soft tissue analogue of Lateral Periodontal Cyst (as it derives from Cell Rests of Serre)

thelium & CT – flat / may show reteridges Nonkeratinised, cuboidal/ overlying epithelium & lie

multiple cystic degeneration

Botryoid Odontogenic Cyst

Uncommon, grossly

multilocular (Botryoid), polycystic variant of odontogenic cyst, first described by Weathers and Waldron (1973) as a type of LPC

They proposed the term

"Botryoid odontogenic cyst"

because the gross specimen resembled a cluster of grapes

multiple cysts / daughter cysts

GLANDULAR ODONTOGENIC CYST

• Arise from remnants of dental lamina

• Oder adults

• M > F

• Mandible > Maxilla

• Ant. region > Post. Region

• Asymptomatic

• Lateral periodontal multilocular radiolucency with sclerotic rim

• Epithelium has glandular or pseudo glandular structure, goblet cells and intra epithelial cysts or micro cysts containing mucous

• Diagnostically superficial layer of epithelium containing columnar or cuboidal cells (referred as hob nail) occasionally with cilia or filiform extensions of the cytoplasm

Synonyms

1. Sialo-odontogenic cyst (Padayachee and Van Wyk) 2. Mucoepidermoid odontogenic cyst

(Sadeghi)

3. Polymorphous odontogenic cyst

KERATINIZING/CALCIFYING EPITHELIAL ODONTOGENIC CYST

• • Central variety – more common

• Peripheral variety – rare

• 2^nd or 3^rd decade

• Maxilla = Mandible

• Ant. region > Post. region

• Central

Usually unilocular, well defined radiolucency

Calcifications or tooth like densities are seen in few cases

May associate with unerupted tooth – canine is common

2 – 4 cm radiolucency

Root resorption or divergence of adjacent teeth is seen

• Peripheral

localized superficial bone resorption or saucer – shaped radiolucency

• Central

Fibrous capsule with 4-10 cell thick odontogenic epithelium

Superficial cells resemble stellate reticulum

Basal cells look similar to ameloblasts

Presence of Ghost cells

Presence of dysplastic dentin

May associate with odontomas

• Peripheral

Islands of odontogenic epithelium in fibrous stroma resembling Ameloblastoma

Nests of ghost cells & juxta epithelial dentinoid

Synonyms

1. Calcifying Odontogenic Cyst 2. Gorlin cyst

3. Dentinogenic Ghost Cell Tumor 4. Calcifying Ghost Cell Odontogenic

Cyst

5. Cystic Keratinizing Tumor

Types 1. Cystic

2. Neoplastic (solid)

ORAL PATHOLOGY Cysts of Oral Region

PATHOGENESIS C/F R/F H/P ADDITIONAL NOTES

ANEURYSMAL BONE CYST (ABC)

• 2 forms

1. Osteolytic initial phase 2. Active growth phase 3. Mature stage/stage of

stabilization 4. Healing phase

• 3 theories

1. Traumatic origin

2. Altered hemodynamic state

3. Secondary phenomenon

• Any age manifestation is swelling with rapid rate of enlargement

• H/O trauma

• Expansion or perforation of cortex and the lesion may exhibit egg shell crackling when covered by periosteum or thin shell of bone.

• Tooth is vital

• Aspirate: dark red or brownish hemorrhagic fluid

• Characteristic ballooning growth pattern resulting in a radiolucent area with elevation of the periosteum to produce an ovoid or fusiform expansion of the bone.

• Usually unilocular

• During surgery, ‘welling up’ of blood within tissue is encountered which is described as blood soaked sponge with large pores

• Lesion consists of capillaries &

blood filled spaces

• Multinucleate cells, scattered osteoid & woven bone are found

• In solid areas: sheets of vascular tissue with giant cells, fibroblasts

& haemosiderin are present

• The blood filled spaces have no characteristic ‘blown out’ contour of bone seen in radiograph of the lesion.

• It is an intra osseous osteolytic lesion mainly affecting the metaphyseal regions of long bone & vertebrae

• Philipsen termed it as Aneurysmal Bone Cavity

• First case of jaw reported by Bernier

& Bhaskar in 1958

• WHO definition: Benign intra-osseous lesion characterized by blood filled spaces of varying size associated with a fibroblastic tissue containing multinucleated giant cells, osteoid & woven bone

Old Terminologies

1. Ossifying hematoma 2. Hemorrhagic osteomyelitis 3. Osteitis fibrosa cystica 4. Expansile hemangioma 5. Aneurysmal giant cell

tumors

PATHOGENESIS C/F R/F H/P ADDITIONAL NOTES

SIMPLE BONE CYST (SBC)

• Trauma

• Failure of differentiation of osteogenic cells

• Venous obstruction

• Osteoclasis due to disturbed

• Unidentified small aneurysm or vascular defect

• Any age, peak in 2^nd decade

• M > F

• Mandible > Maxilla

• Most common in premolar area

• Asymptomatic usually an incidental finding

• Occasional pain, swelling &

paresthesia may be present

• H/O trauma

• 3 distinctive features (Lucas) 1. Area of radiolucency

larger than the size of swelling suggests 2. Cavity arch between the

roots of the teeth

3. Outline typically irregular

• SBC often located above and in front of the mandibular canal

• Scalloping is a prominent membrane of variable thickness

• C.T lining overlies zone of reactive bone that exhibits an extensive osteophytic reaction on outer cortical plate

• Hemorrhage, haemosiderin, small multinucleate cells

• Areas of hemorrhage with necrotic tissue & myxoid degeneration

• First described by Lucas 1929

• Resembles unicameral bone cavity which is analogous lesion of long bone

• WHO definition: Solitary bone cyst is an intra-osseous cyst having a tenuous lining of connective tissue with no epithelial lining

Synonyms

1. Solitary bone cyst 2. Traumatic bone cyst 3. Hemorrhagic bone cyst 4. Unicameral bone cyst 5. Idiopathic bone cavity

Rushton’s (1949) criteria for diagnosing SBC

• Cyst should be single, no epithelial lining, no evidence of acute or prolonged infection

• Principally contain fluid & not soft tissue

• Walls should be hard bone, which may be thin in parts

• Pathological & chemical findings do not exclude a diagnosis of SBC

ORAL PATHOLOGY Cysts of Oral Region

PATHOGENESIS C/F R/F H/P ADDITIONAL NOTES

STAFNE’S BONE CAVITY

• Glandular Hypothesis Hyperplastic/hypertrophic or aberrant lobe of salivary gland

Pressure resorption

• Any age, peak in 5^th & 6^th decade

• M > F

• Mandible > Maxilla

• Most common in angle of mandible & 1^st molar below inferior alveolar canal

• Typically asymptomatic

• Not palpable

• Routinely detected on radiographs

• Round or ovoid radiolucency with radiopaque borders

• Submandibular salivary gland tissue may extend into lingual bone depression

• Surface of depressions show osteoclastic activity

• May contain normal, hyperplastic or hypertrophic salivary gland tissue

• The term first coined by Stafne in 1942

• Also called as Lingual Mandibular Bone Depression (LMBD)

1. Lingual posterior variant:

localized in posterior lingual mandible in area of angle `1& below inferior alveolar canal

2. Anterior LMBD: localized in mandibular incisor-canine-premolar area above the mylohyoid muscle.

3. Ascending lingual mandibular ramus (MRBD): localized posterior to lingual foramen, just below the neck of condyle

4. Buccal aspect of ascending mandibular ramus

Other Synonyms

1. Mandibular embryonic defect

2. Latent bone cavity 3. Idiopathic bone cavity 4. Lingual mandibular SG

depression

5. Latent hemorrhagic cyst of

the mandible

6. Aberrant salivary gland tissue in the mandible FOCAL OSTEOPOROTIC BONE MARROW DEFECT

• Aberrant form of bone healing with focal formation of hematopoietic bone marrow

• Persistence of fetal marrow

• Peak in 4^th & 5^th decade

• F > M

• Mandible > Maxilla

• Most common in molar-ramus area, premolar region of mandible, maxillary tuberosity

• Generally asymptomatic

• Occurs at sites of recent surgical interventions

• Irregular round or oval radiolucency

• Anterior border may be well delineated and may be sclerotic

• Tissue may be either normal red marrow, fatty marrow or both

• Lymphoid aggregates may be present

• Trabeculae: thin, irregular &

devoid of osteoblastic layer

• First described by Cahn in 1954

Synonyms

1. Osteoporotic marrow defect of jaw

2. Hematopoietic defect of the jaw

3. Focal marrow containing jaw cavity (FMJC)

ANTRAL PSEUDOCYST

• H/O previous infection Focal accumulation of inflammatory exudate

Lifting of antral mucosa from underlying bone

• M > F

• Most common in antral floor

• Generally asymptomatic

• Well defined radioopacities, spherical, ovoid or dome shaped lesion with a smooth uniform outline

• Pools of mucoid material lined by inflamed fibrous C.T

• Mucoid infiltrate appears primarily to be an inflammatory infiltrate

• Mucin stains negative

Synonyms

1. Benign mucosal cyst of maxillary antrum

2. Mucosal cyst 3. Serous cyst 4. Non-secreting cyst

ORAL PATHOLOGY Cysts of Oral Region

Pseudocyst Antral polyp

May be single or multiple Multiple

Fluid accumulates beneath the periosteum Fluid accumulates in the loose C.T of lamina propria of lining of sino nasal tract

In document PLAN DE EXPANSION DE LA GENERACION ELECTRICA PERIODO (página 80-84)