Ch14 Bone Path (Part III) Flashcards
This is ridiculous…what are the 5 alternate names for Simple Bone Cyst?
1.Traumatic Bone Cyst 2. Hemorrhagic bone cyst 3. Solitary bone cyst 4. idiopathic bone cavity 5. unicameral bone cyst
Why is a simple bone cyst not really a cyst?
It lacks a lining, thus really a pseudocyst and not a true cyst
The trauma-hemorrhage theory for the cause of a simple bone cyst is that a ________ forms but does not organize and repair, just liquefies
hematoma
Simple bone cysts have been reported in almost EVERY bone in the body..but what are the two most common sites?
proximal humerous and proximal femur
What is the most common location of a simple bone cyst that shows up in the jaw?
marked mandibular predominance..PM, molar, and symphyseal regions
Simple bone cyst: age? gender?
young, peak in 2nd decade…no gender preference (extragnathic has male predilection)
What % of simple bone cysts in the jaw present with swelling?
20%
What is a HIGHLY SUGGESTIVE (but not clearly diagnostic) feature of a simple bone cyst on a radiograph?
scalloping between tooth roots
What may arise in conjunction with a simple bone cyst? What age and gender demographic is this most likely?
cemento-osseous dysplasia…older females
Simple bone cyst: in lieu of an epithelial lining there may be what 2 features?
- a thin vascular connective tissue membrane adjacent to the bone 2. a thickened myxofibromatous proliferation
Clinically, when opened 1/3 of simple bone cysts will be ______ and 2/3 will have _______
1/3 empty…2/3 small amounts of serosanguinis fluid
Interesting…How are EXTRAGNATHIC simple bone cysts treated? What is the recurrence rate?
aggressively: curettage, cryosurgery, decompression, intralesional steroid injection, bone substitiute/marrow injection/grafting…29% (range 12-48%)
How are simple bone cysts of the jaw treated? Recurrence rate?
surgical exploration and curettage, usually stimulates bone regeneration..1-2% (some report as high as 27%)
What increases the chance of recurrence for a simple bone cyst in the jaw? (2)
multiple cysts and assoc w COD
How long does it take for simple bone cysts to resolve post enucleation?
12-17 months post surgery
The ___________ is an intraosseous accumulation of variable-sized, blood-filled spaces surrounded by cellular fibrous connective tissue and reactive bone. Because the lesion lacks an epithelial lining, it represents a _______.
aneurysmal bone cyst… pseudocyst
What % of aneurysmal bone cysts form in association with other lesions?
20-30%
GENETICS for aneurysmal bone cysts indicate it is a neoplastic process…what gene is involved? Chromosome?
Ubuiquitin-specific protease 6 (USP6) (or Tre-2/TRE17)…Chromosome 7p13
Where are the typical site for ABCs? Age? Gender? What % of cases involve the jaws and what age?
long bones and vertebrae, pts younger than 30 then vertbre…no sex predilection (possible slight female predilection).. 2% and peak in 2nd decade
When an ABC shows up in the jaw, where is it most likely? Where does it not show up?
Common in ascending ramus and posterior body, but NOT in condylar or coronoid process
What is the MOST COMMON clinical manifestation of an ABC?
RAPID swelling (pain is variable, paresthesia, crepitus noted variably)
ABC: Radiographic buzzwords…
Balooning or “blow out” distension of the affected bone
ABC: Buzzword for clinical appearance during enucleation…
“blood soaked sponge” (venous-like bleeding)
ABC Histology: characterized by ______ that LACK ______…sourrounding these structures is fibroblastic tissue with what three features?
blood-filled spaces…lack endothelial or epithelial lining…giant cells, osteoid, and woven bone
What two entities are most commonly associated with ABCs when discovered histologically?
fibro-osseus lesions or giant cell granulomas
How long does an ABC take to heal post enucleation?
6mo to 1 year
What is the recurrence rate for ABCs?
13% (has been reported between 8-70% lol)
What are the 4 possible categories (not specific entities) of fibro-osseuos lesions?
- developmental (hamartomatous) 2.reactive 3.dysplastic 4.neoplastic
What are the three specific types of fibro-osseous lesions of the jaw?
1.Fibrous Dysplasia 2.Cemento-osseuos dysplasia (focal, periapical, florid) 3. ossifying fibroma
What TYPE of lesion is fibrous dysplasia?
developmental tumorlike condititon lol
Fibrous dysplasia is characterized by replacement of normal bone by a proliferation of _________ with irregular ______.
cellular fibrous connective tissue….bony trabeculae
What is the distinguishing genetic factor in fibrous dysplasia, thus separating it from OF or COD?
mutations in the GNAS gene
Fibrous dysplasia: This SPORADIC condition results from _______, activating mutations in the ____ gene, which encodes the ______ subunit of a stimulatory __ protein.
post zygotic…GNAS gene..alpha….G
In some cases of fibrous dysplasia, involvement of multiple bones may occur in conjunction with _______ and ______ abnormalities.
cutaneous…endocrine
Buckle in: Fibrous Dysplasia–TIMING of the GNAS mutation: During EARLY embryonic development, mutation of a pluripotent stem cell can cause abnormalities in multiple cell types, including WHAT 3 cell types?
osteoblasts, melanocytes, and endocrine cells
Buckle in: Fibrous Dysplasia–TIMING of the GNAS mutation: if the mutation occurs in a skeletal progenitor cell in a LATER stage of embryonic development, then only _______ will be affected.
osteoblasts
Buckle in: Fibrous Dysplasia–TIMING of the GNAS mutation: if the mutation occurs during POSTNATAL
life, then ________ in only a SINGLE BONE will be affected
osteoblasts
Buckle in: Fibrous Dysplasia–the PARENTAL origin of the mutated GNAS allele may affect the phenotype, in certain cell types (such as pituitary somatotrophs) genomic imprinting results in expression of only the _______ allele
MATERNAL
Buckle in: Fibrous Dysplasia–Constitutive activation of _______ signaling IMPAIRS ______ differentiation in skeletal progenitor cells, STIMULATES _______ production in melanocytes, and causes HYPERPLASIA and HYPERFUNCTION of various _______ cell types.
G-protein…osteoblastic….melanin…endocrine
Fibrous Dysplasia: mutated osteoblasts overexpress ______, which stimulates osteoclastic activity and may contribute to bone lesion expansion
interleukin (IL)-6
What is more common: monostotic or polyostotic fibrous dysplasia?
monostotic…one bone affected in 70-85% of pts
Monostotic fibrous dysplasia: age? sex? sites?
2nd-3rd decades..equal frequency…craniofacial bones, ribs, femur, tibia
When monostoic fibrous dysplasia occurs in the jaw which jaw is most affected? What region of that jaw?
posterior maxilla
What is typically the clinical indication of fibrous dysplasia?
PAINLESS unilateral swelling
Fibrous dysplasia: typically rapid or slow onset? What happens to the teeth?
TYPICALLY slow onset (can be fairly rapid though)…adjacent teeth can be DISPLACED, but usually remain FIRM (so NO mobility)
The classic radiographic finding of fibrous dysplasia is “________” with ______ defined margins
ground glass opacification…POORLY defined margins
What is the more appropriate term for when fibrous dysplasia extends beyond the maxilla and into adjacent bones?
crainiofacial fibrous dysplasia
Mandibular lesions of fibrous dysplasia often exhibit __________ expansion and bulging of the _______ border. There may be SUPERIOR displacement of the _________.
buccal - lingual….inferior…IA canal
PAs of fibrous dysplasia show _______ of the PDL and ill-defined lamina dura
NARROWING
What syndromes are associated with polyostoic fibrous dysplasia?
1) Jaffe-Lichtenstein syndrome 2) McCune-Albright Syndrome 3) Mazabraud
What age is polyostoic fibrous dysplasia typically diagnosed? Gender? Up to __% of the entire skeleton can be affected…
BEFORE age 10…Female predilection…75%
What are the three buzzwords for finding polyostoic fibrous dysplasia in the proximal FEMUR?
coxa vara, shepherd’s crook deformity, or hockey stick deformity
Polyostoic fibrous dysplasia: WHAT blood test finding is common?? What is the cause?
Hypophosphatemia….caused by renal phosphate wasting
Polyostoic fibrous dysplasia: Hypophosphatemia appears to be related to the release of ________ by the affected bones.
fibroblast growth factor 23 (FGF23)
__________ is characterized by polyostotic fibrous dysplasia and café au lait (coffee with milk) pigmentation
Jaffe-Lichtenstein syndrome
_________ is characterized by polyostotic fibrous dysplasia, café au lait pigmentation, and multiple endocrinopathies
McCune-Albright syndrome
________ is characterized by fibrous dysplasia and intramuscular myxomas
MA-ZA-BRAUD syndrome
What is the difference between cafe au lait pigmentation in fibrous dysplasia vs neurofibromatosis?
FD = irregular margins (coast of Maine)…. NF = smooth borders (coast of California)
Since we already know that McCune-Albright syndrome is set apart by the presence endocrineopathies…what IS the #1 endocrineopathy seen? What gender?
sexual precocity in females (menses, breast dev, pubic hair present in first months/years of life)
Since we all know that sexual precocity in females is the most common endocrinopathy in McCune-Albright patients, what are the 4 other possibilities?
- hyperthyroidism 2. hyperparathyroidism 3. hypercortisolism 4.excess growth hormone
craniofacial fibrous dysplasia mainly occurring in _________, investigators have reported various dental anomalies, including tooth displacement, oligodontia, enamel hypoplasia, enamel hypomineralization, taurodontism, and retained deciduous teeth.
McCune-Albright syndrome
Fibrous dysplasia histology: irregularly shaped trabeculae of ______ (_____) bone in a cellular ______ stroma.
immature (woven)…fibrous
Fibrous dysplasia histology: At the PERIPHERY, the lesional bone FUSES with normal bone, without a ______ or line of demarcation.
capsule
Fibrous dysplasia histology: The abnormal bony trabeculae tend to be thin and disconnected, with curvilinear shapes likened to “________”.
Chinese characters
Fibrous dysplasia histology: Osteoblastic ______ is usually ABSENT or minimal, and peritrabecular ______ (artifactual retraction of the stromal from the bony trabeculae) is COMMON
rimming..clefting
Fibrous dysplasia histology: In addition, tiny calcified _______ rarely may be seen but are never numerous.
spherules
Fibrous dysplasia histology: In LATER stages, the WOVEN bone is replaced by ______ bone with roughly PARALLEL trabeculae
LAMELLAR
Fibrous dysplasia histology: what cyst can be seen secondarily?
ANEURYSMAL BONE CYST
What is a generalized difference in pattern between fibrous dysplasia and ossifying fibroma / COD?
FD: MONOTONOUS pattern vs OF/COD=HAPHAZARD
What are two microscopic variations in fibrous dysplasia?
PAGETOID (thick, interconnected bone trabeculae) and HYPERCELLULAR (parallel bone trabeculae with numerous osteocytes and polarized osteoblastic rimming)
Fibrous dysplasia tends to stabilize upon WHAT EVENT??, and spontaneous regression even has been reported in a few cases.
skeletal maturation
Fibrous dysplasia: ___% to ___% of patients show some REGROWTH after surgical debulking…risk is greater for WHICH age group?
20-50%..greater risk of regrowth for YOUNG pts
More studies needed, but: fibrous dysplasia and which blood marker to predict recurrence?
Serum alkaline phosphatase
Fibrous dysplasia: what treatment is CONTRAINDICATED?
radiation therapy…risk of post rad sarcoma
What is the risk of fibrous dysplasia transforming to osterosarcoma? What 3 situations INCREASE the risk?
less than 1%…1) radiation therapy 2)McCune-Albright Syndrome 3)MAZA-BRAUD syndrome
