Pseudocysts Flashcards
What are pesudocysts?
- They have no epithelial lining.
- They’re called cysts by convention just because that’s what everybody is used to
- They’re not true cysts.
pesudocysts
List
(5)
- Aneurysmal Bone Cyst
- Antral Pseudocyst
- Simple Bone Cyst
- Osteoporotic Bone Marrow Defect
- Stafne Bone Cyst
Aneurysmal Bone Cyst
Demographics
■ Most common site in the body is long bones or vertebrae
_■ In the jaw_s, most frequently seen in the 1st and 2nd decade
■ MD > MX
it’s a pesudocyst
Aneurysmal Bone Cyst
Clinically
- swelling, frequently a rather rapid swelling
- often with pain and/or paresthesia (signs which can be suggestive of the presence of a malignant or aggressive lesion)
Aneurysmal Bone Cyst
Etiology
- Etiology is unclear, may result from trauma or a vascular malformation
- most agree that it is a reactive and *not* a neoplastic lesion
Aneurysmal Bone Cyst
Radiographically
■ a radiolucency which can be either unilocular or multilocular in appearance
■ Borders are variable, often irregular in shape and may be ill-defined (again, giving the suggestion of malignancy)
■ Teeth may be displaced
■ we may see cortical expansion and thinning ~ the cortex itself can become quite thin
What does this person have?
- you might think that he has an odontogenic infection but he didn’t. You can see that there’s
a pretty significant swelling on the left side of his face
This is a Aneurysmal Bone Cysts
Aneurysmal Bone Cyst
you can see that there is kind of a
multilocular radiolucency in this particular area
Aneurysmal Bone Cyst
✎ There’s a radiolucency involving the second molar
that’s going as far anterior as the first molar and back
to the third molar
✎ There is a little bit of spiking root resorption and
that’s one of the signs that we associate with
malignancy
✎ It’s a little bit ill-defined ~ hard to say exactly
where it begins and ends
Aneurysmal Bone Cyst
Histology
■ An intraosseous accumulation of variously sized blood filled sinusoidal spaces (not lined by endothelium)
surrounded by cellular fibroblastic tissue
■ Woven (reactive, immature) bone may be seen in the FCT
■ Gross appearance of a “blood soaked sponge”
■ The connective tissue can contain multinucleated giant cells and extravasated red blood cells
Aneurysmal Bone Cyst
✎ It looks like a blood soaked sponge
✎ There’s these open sinusoidal spaces and then fibrous connective tissue surrounding them.
✎The sinusoidal spaces can vary in size; some of them are fairly small and others are large
Wall of the aneurysmal bone cyst can have a histology similar to the following
✎ Central giant cell granuloma
✎ Cherubism
✎ Brown tumor of hyperparathyroidism
Aneurysmal Bone Cyst
Histology
Left Image: you can see some of them are fairly small, little spaces within the connective tissue and others are large
✎ at the edges, you do not see endothelia lining, so
these are not vessels neither veins or arteries because they’re not endothelia lined
✎They are just these spaces within this fibrous connective tissue, referred to as sinusoids. You can see that there’s bone trabeculae down here on the left
Middle: On high power, there’s multinucleated giant cells (red) within the fibrous connective tissue and then there’s extravasated red blood cells within the connective
tissue
Right: On higher power; (red) would be the lumen of those sinusoidal spaces. Below that is the connective tissue and you can see there’s no endothelia lining, there’s just fibrous connective tissue and then some
multinucleated giant cells
Aneurysmal Bone Cyst
Treatment
■ Treatment is surgical enucleation and curettage
■ lesions can recur ~ Usually the recurrence is because
you didn’t get the entire thing out the first time around
■ Some surgeons follow enucleation with cryotherapy
■ Irradiation is contraindicated
Is bleeding a concern during surgical removal of Aneurysmal Bone Cyst?
■ No, vascularity is predominantly “low flow”, therefore not as much concern for bleeding upon surgical removal
■ As compared with central hemangioma where there is a concen for bleeding
Antral Pseudocyst
They are different than surgical ciliated cyst
in their lining, etiology, location and appearance!
As opposed of surgical ciliated cysts, Antral psuedocysts are not —-
( in term of their lining)
Not epithelial lined spaces
As opposed of surgical ciliated cysts, Antral psuedocysts are not —-
( in term of location)
Not within the bone but are in the sinus
As opposed of surgical ciliated cysts, Antral psuedocysts Develop as —-
( in term of etiology)
develop as an accumulation of an inflammatory exudate (often serum) between the sinus epithelial lining and the bone
-It develops because of an inflammatory event in the jaw, usually the maxilla, often from the roots of the maxillary teeth that cause inflammation
As opposed of surgical ciliated cysts, Antral psuedocysts appear as —-
( in term of Radiology)
Appears as a dome shaped elevation of the floor of the sinus
Antral Pseudocyst
- a Dome-shape swelling on the floor of the sinus.
- They can sometimes be fairly subtle
Antral Pseduocyst are NOT Mucoceles
Mucoceles would have more of meniscus-like
appearancewhere it would come up tothe edge of
the sinus
Aneurysmal Bone Cyst
✎ A dome shape swelling on the floor of the sinus that’s associated with some _sort of inflammation of tooth of t_he premolar caused inflammation underneath the apex of the bone (right) and then that leads to accumulation of fluid which causes the sinus lining to elevate off the bone and fill with fluid
✎ After root canal therapy and once the infection gets under control, these will typically resolve on their own
Simple Bone Cyst
also known as
aka traumatic bone cyst
Simple Bone Cyst
Charcterstics
- A benign, empty or fluid filled, cavity in bone which is devoid of an epithelial lining – a pseudocyst
- Thought to be reactive, NOT neoplastic
Simple Bone Cyst
Etiology
Etiology ununcertain, theories include:
- trauma
- ischemic necrosis of medullary space
- cystic degeneration of a primary bone lesion
Simple Bone Cyst
Demographics
- In jaws, most likely in the 2nd decade
- Almost exclusively the mandible
- Twice as common in males
Simple Bone Cyst
Radiographically
- a well-circumscribed radiolucency with an irregular outline
- Tendency to “scallop” around and between roots (highly suggestive, but not diagnostic of this lesion)
Simple Bone Cyst
Histology
- We see only scant delicate vascularized FCT
Simple Bone Cyst
Treatment
- exploration and curettage of space to create bleeding. Clot will organize and allow bone repair
- Recurrence is rare
Simple Bone Cyst
✎A well-circumscribed with cortication in the body of the
mandible, affecting the posterior aspect (premolars and the molars )
✎Note the scalloping that happens up between the roots. It
doesn’t cause root resorption and actually the lesion will grow up between the roots of the teeth
Simple Bone Cyst
- A well-circumscribedshowing the scalloping up between the roots of the teeth radiolucency
Simple Bone Cyst
✎Big lesion example: It’s going back to the molar area here.
✎You can see that the lesion extends over to the canine on the other side
✎Most lesions are usually in the anterior mandible
Simple Bone Cyst
Histology
✎This is an example of a curetting from the socket and you can see there’s some bone trabeculae on the bottom
of the image
✎There really isn’t any epithelial lining because it’s a pseudocyst. It’s really just vessels and in fibrous connective
tissue
Osteoporotic Bone Marrow Defect
Charcteristics
- it’s a pesydocyst
- a radiolucency in an area typically
where tooth has been removed. Instead of filling in with bone, it fills in with marrow. - When we biopsy it, you’re seeing the hematopoietic elements. (fat, early stages of (the -blasts of) red cells,
white cells. - We see basic bone forming marrow content
Osteoporotic Bone Marrow Defect
Demographic
■ Uncommon finding
■ > 75% of cases are in females
■ ~ 70% occur in the posterior MD, often in an edentulous area
it’s a pesydocyst
Osteoporotic Bone Marrow Defect
Etiology
- Etiology unclear
- may be hyperplasia of marrow due to need for RBCs or
- abnormal regeneration of bone after an extraction or persistence of fetal marrow
Osteoporotic Bone Marrow Defect
Hematopoietic bone marrow defect
Osteoporotic Bone Marrow Defect
Clincalally
■ Typically asymptomatic and found on routine radiographic exam
Osteoporotic Bone Marrow Defect
Radiographically
- Irregularly shaped radiolucency with either a well-defined or ill-defined border (It can be in the differential diagnosis with malignancy)
Osteoporotic Bone Marrow Defect
Histologically
■ a cellular hematopoietic marrow is seen with fewer than the normal numbers of fat cells
■ Must biopsy to make a definitive diagnosis
Osteoporotic Bone Marrow Defect
Treatment
■ Must biopsy to make a definitive diagnosis
■ No further treatment is then necessary
~ You don’t have to remove it; you can just leave it as it is
- You can see there’s a little bit of radiolucency.
- There happened to actually still be teeth in the area, but
- when it was biopsied it showed that it was a
- hematopoietic or osteopoietic bone marrow defect
Osteoporotic Bone Marrow Defect
histology
On biopsy : there’s basically just
blood-forming elements and fat, which is pretty
much all that there is in that lesion
Stafne Bone Cyst
also known as
static bone cyst, Stafne defect
Stafne Bone Cyst
Charcterstics
■ An asymptomatic focal concavity of the cortical bone on the lingual aspect of the MD
■ A pseudocyst, not a true cyst
Stafne Bone Cyst
Demographics and Location
- Most commonly found near the angle of the mandible below the inferior alveolar nerve (but also seen in the anterior MD)
- > 80% in Males
- usually noted only in adults
Stafne Bone Cyst
Radiographically
Oval round well-circumcribed radilucency
Below the Inferior Alveolar Nerve
Stafne Bone Cyst
Etiology
- Believed to be developmental in origin, but usually noted only in _adults_
Stafne Bone Cyst
Treatment
- lesions in the posterior MD are usually pathognomonic
- no further treatment is necessary
Stafne Bone Cyst
This is the classic look.
- a well-circumscribed corticated radiolucency
- below the inferior alveolar nerve, away from the teeth.
- They can be either oval, like this, or round in appearance
Stafne Bone Cyst
Less common location
Check if the teeth were vital with vitality test
Get a CBCT in that area
to see what was going on first and then once you saw
the CBCT you’d be able to make the diagnosis.
Stafne Bone Cyst
Histology
When biopsied, usually get normal salivary gland tissue, but most likely because gland has expanded into the defect
Stafne Bone Cyst
What we see on biopsy:
✎It’s just salivary gland tissue b_ecause the salivary glands grow into that space_
✎ It’s an empty space that they can grow into and that’s what they do; they just expand into that location. It’s not that the salivary gland is causing it
