Bone: Disorders, Cysts, & Tumors Flashcards
What is Fibrous Dysplasia?
FIBROUS DYSPLASIA of bone is a DISORDER where normal bone and marrow is REPLACED with fibrous tissue, resulting in formation of bone that is weak and PRONE TO EXPANSION
As a result, WEAKNESS; most complications result from fracture, deformity, functional impairment and PAIN.
Monostotic (75%-80%); polyostotic (20%-25%)
What is an ossifying fibroma?
FIBROUS + CALCIFYING
OSSIFYING FIBROMA is a SLOW growing BENIGN bone NEOPLASM often considered to be a type of fibro-osseous lesion.
This bone tumor consists of HIGHLY CELLULAR , fibrous tissue that contains varying amounts of CALCIFIED tissue-resembling bone, cementum, or both.
Other names for OF: (osteofibroma, fibro-osteoma, cementifying fibroma. cemento-ossifying fibroma)
What are differences between an Ossifying Fibroma and Fibrous Dysplasia?
OSSIFYING FIBROMA is a NEOPLASM that, if left untreated, may exhibit considerable growth and bone destruction.
In contrast to fibrous dysplasia, ossifying fibroma is WELL CIRCUMSCRIBED and usually EASILY EXCISED when small.
FIBROUS DYSPLASIA- Disease may stabilize at puberty, so in children, therapy should be delayed if possible until after puberty
Age and Gender for:
- Ossifying Fibroma
- Juvenile Ossifying Fibroma
- Fibrous Dysplasia
- OF - has a predilection for FEMALES (70%) between the SECOND and FOURTH (20-40) decades of life.
- JOF - F= M; usually in children UNDER 15
- FD - F = M; first 2 decades (0-20)
What is the Radiographic presentation of Fibrous Dysplasia?
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Radiographically, FIBROUS DYSPLASIA classically appears with a radiodense “ORANGE-PEEL or GROUND GLASS” texture that BLENDS IMPERCEPTIBLY into normal bone.
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Fibrous Dysplasia is associated with what syndrome?
McCune-Albright syndrome
(Polyostic Fibrous Dysplasia)
(1%-3% of FD)
What malignancies can Fibrous Dysplasia turn into?
Very Rare transformation (~1%)
For unknown reasons, MONOstotic and CRANIOFACIAL lesions have the greatest potential for malignant transformation. Usually associated with a history of prior radiation treatment.
Malignant transformation of FD is rare and involves transformation into 1. Osteosarcoma 2. Fibrosarcoma 3. Chondrosarcoma in decreasing order of frequency.
Location differences between Ossifying Fibroma and Juvenile Ossifying Fibroma
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OF - Mandible > > maxilla (90%), premolar-molar area specifically
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JOF - Maxilla and paranasal sinuses more common than mandible
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What is McCune-Albright syndrome?(Albright syndrome)
McCUNE–ALBRIGHT syndrome is a complex genetic disorder affecting the BONE, SKIN, and ENDOCRINE systems.
Suspected when TWO OR MORE of the following features are present:
- Polyostic Fibrous Dysplasia. (multiple bones)
- Café au lait MACULES, including characteristic jagged “COAST OF MAINE” borders and tendency NOT TO CROSS THE MIDLINE.
- HYPER-functioning endocrine disease.
- Precocious puberty (females primarily)
- Hyperthyroidism (~38%)
What is Osteosarcoma?
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Osteosarcoma is a MALIGNANCY of MESENCHYMAL cells that produces IMMATURE bone.
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It is the MOST COMMON type of cancer that arises in BONES, and it is usually found at the end of long bones, often around the knee. It is uncommon in jaws.
Very rare under 5yo, peak incidence 15yo
Higher incidence in Blacks/Hispanics
Fewer than 20,000 US cases per year
Most people diagnosed with osteosarcoma are UNDER the age of 25, and it is thought to occur more often in MALES than females.
In Jaws: most common initial symptom is JAW ENLARGEMENT (Posterior Mandible) +/- PARESTHESIA
Spiky ROOT RESORPTION with WIDENING PDL.
If the disease is localized the long-term survival rate is 70 to 75%.
If spread to the lungs or other bones at diagnosis, the long-term survival rate is about 30%.
What is Ewing’s Sarcoma? 🧬
EWING’S sarcoma is a type of cancer that forms in BONE or SOFT tissue around bones
MOST CASES of Ewing’s sarcoma (85%) are the result of a TRANSLOCATION between CHROMOSOMES 🧬 11 and 22, which fuses the EWS gene of chromosome 22 to the FLI1 gene of chromosome 11.
LONG BONES of the pelvis, legs or arms, but it can occur in any bone.
Ewing sarcoma is the SECOND most common type of bone cancer in children, but it is very rare. About 200 children and young adults are found to have Ewing sarcoma each year in the United States.
About half of all Ewing sarcoma tumors occur in children and young adults between ages 10 and 20.
Most cases are CAUCASIAN race
The classic description of lamellated or “ONION-SKIN” type periosteal reaction is often associated with this lesion.
About 70 percent of children with Ewing sarcoma are cured.
Teens aged 15 to 19 have a lower survival rate of about 56 percent.
For children diagnosed after their disease has spread, the survival rate is less than 30 percent.
What is Osteomyelitis?
Osteomyelitis is an infection and inflammation of the bone or the bone marrow.
It can happen if a bacterial or fungal infection enters the bone tissue from the bloodstream, due to injury or surgery.
What is a Neoplasm?
A neoplasm is an ABNORMAL NEW GROWTH of cells. The cells in a neoplasm usually grow MORE RAPIDLY than normal cells and will continue to grow if not treated.
When cells DIVIDE more than they should or DO NOT DIE when they should.
As they grow, neoplasms can impinge upon and damage adjacent structures. The term neoplasm can refer to BENIGN (usually curable) or MALIGNANT (cancerous) growths.
A Dentigerous Cyst can turn into what neoplasia?
Ameloblastoma
Odontogenic Keratocysts has what features?
- locally aggressive DEVELOPMENTAL cyst.
- originate from the odontogenic epithelium (DENTAL LAMINA) in the alveolus left from tooth development stages. They are mainly thought to arise from RESTS OF SERRES.
- At least 50% of odontogenic keratocysts are found in POSTERIOR part and lower RAMUS of the mandible, make up around 19% of all jaw cysts.
- MULTIPLE odontogenic keratocysts are a feature, and major diagnostic criteria, of NEVOID BASAL CELL CARCINOMA syndrome
Primordial Cysts?
PRIMORDIAL CYST
- DEVELOPMENTAL odontogenic cyst.
- lesions displays a parakeratinized epithelium with palisading basal epithelial cells.
- infrequent cystic MANDIBULAR lesions, which are thought to result from DEGENERATION of DENTAL FOLLICLES.
- NO TOOTH is therefore present, and the cyst is a well defined, small and static lesion, most commonly located posteriorly in the region of the THIRD MOLAR or ANGLE of the mandible.
- Most “primordial cysts” are actually Keratocyst odontogenic tumors (KOT’s).
Robinson’s classification of Ameloblastomas
AMELOBLASTOMA
- It is a TUMOR of the ENAMEL ORGAN without formation of enamel.
- In 1937, Robinson has defined it as:
- Unicentric (having a single center of origin)
- Nonfunctional
- Intermittent in growth
- Anatomically benign
- Clinically persistent.
Radiographic finding in a Pindborg Tumor?
PINDBORG TUMOR
A.K.A. - Calcifying Epithelial Odontogenic Tumor (CEOT)
- is known for sometimes having SMALL RADIOPACITIES (white areas) within it. In those instances, it is described as having a “DRIVEN-SNOW” appearance. Microscopically, there are deposits of amyloid-like material.
- It is a typically BENIGN and SLOW growing, but INVASIVE neoplasm.
- It is more common in the POSTERIOR MANDIBLE of adults, typically in the fourth to fifth decades. There may be a PAINLESS SWELLING, and it is often concurrent with an IMPACTED TOOTH.
2/3 posterior, 1/3 anterior maxilla
The most ideal explanation for RECURRENCE of Odontogenic Keratocysts is?
Presence of satellite cysts or daughter cysts.
Recurrence was also found more frequently in cysts with MULTILOCULAR radiographic appearance than in unilocular cysts.
- The odontogenic keratocyst (OKC) is known for its HIGH RECURRENCE rate, AGGRESSIVE behavior, and its occasional association with the nevoid basal cell carcinoma syndrome (NBCCS).
- Recurrence of keratocysts in patients WITH basal cell nevus syndrome occurred more frequently than that of patients without the syndrome.
The cyst with the highest recurrence rate is?
Odontogenic Keratocyst (KOT)
The epithelium can separate from the wall, resulting in islands of epithelium. These can go on to form ‘satellite’ or ‘daughter’ cysts, leading to an overall multilocular cyst. Presence of daughter cysts is particularly seen in those with NBCCS.
