663 Benign tumors, Malignant diseases

What are benign tumors?

= Abnormal masses of tissue that develop as a result of uncontrolled cell proliferation

- tend to resemble tissue of origin

- grow slowly, spread locally, and do not metastasize

Radiographic signs most benign tumors have in common:

- Shape

- Margins

- Effect on surrounding structures

- Shape: round or scalloped

- Margins: well-defined and corticated

- Effect on surrounding structures: displacement, thinning, expansion

Benign tumors of the jaws can be divided into 2 main categories:

- what are 3 subcategories?

Odontogenic and non-odontogenic

Sub-categories:

- Ectodermal

- Mixed

- Mesodermal

Ameloblastoma has a predilection for what location?

posterior mandible

Ameloblastoma

- Density

- Internal architecture

- Effect on surrounding structure

- Density: radiolucent

- Internal architecture: unilocular or multilocular

- Effect on surrounding structure: root resorption

Ameloblastoma ex

- Root resorption

- Expansive

- Multilocular

Odontoma - unique features

- Density

- Internal architecture

- Density: mixed RL-RP

- Internal architecture: amorphous or tooth-like

Compound vs complex odontoma

Complex: does not show any tooth-like structures

Compound odontoma ex

Little tooth-like structures

Difference between ameloblastic fibroma and ameloblastic fibroodontoma

Ameloblastic fibroma:

- NO RP calcifications

Ameloblastic fibroodontoma:

- HAS RP calcifications

Odontogenic myxoma - unique features

- Margins

- Density

- Internal architecture

- Margins: well-defined or ill-defined

- Density: radiolucent

- Internal architecture: unilocular or multilocular

Odontogenic myxoma - distinct feature

Many very fine septae throughout

Benign cementoblastoma - unique features

- Location

- Density

- Internal architecture

- Effect on surrounding structures

- Location: often mandibular molar or premolar

- Density: mixed RL-RP

- Internal architecture: large central radiopacity

- Effect on surrounding structures: root resorption

Benign neural tumors are usually located where?

in the mandibular canal

Benign neural tumors - unique features

- Density

- Internal architecture

- Effect on surrounding structures

- Density: radiolucent

- Internal architecture: unilocular

- Effect on surrounding structures: canal expansion

Osteoma - most common location? (2)

- On medial surface of ramus

- In the paranasal sinuses

Osteoma

- density

- internal architecture

- density: RP or mixed

- internal architecture: homogeneous or mixed

Ossifying fibroma - unique features

- Density

- Internal architecture

- Density: mixed RL-RP

- Internal architecture: variable

What are malignant diseases?

= Abnormal growths of tissue that develop as a result of uncontrolled and unlimited cell proliferation

- show aggressive growth patterns

- invade adjacent normal tissues

- can metastasize via lymphatic or vascular systems or through perineural spread

Radiographic signs most malignant diseases have in common:

- Shape

- Margins

- Density

- Effect on surrounding structures

- Shape: irregular

- Margins: ill-defined

- Density: radiolucent

- Effect on surrounding structures: erosion, destruction

Squamous cell carcinoma - unique features

- location?

Peripheral or central (starts inside bone)

Which metatstaic disease often shows "floating teeth?"

Squamous cell carcinoma

Squamous cell carcinoma ex

Soft tissue mass has destroyed everything around it --> very aggressive

An adenoid cystic carcinoma comes from...

salivary glands

Adenoid cystic carcinoma

- location

Palate

Which malignant disease is known to have a sun-ray periosteal reaction?

Osteosarcoma

Osteosarcoma - density?

Radiolucent or mixed RL-RP

Osteosarcoma

- effect on surrounding structures?

- sun ray periosteal reaction

- low-grade lesions appear more benign

- asymmetric, irregular widening of the PDL space

Osteosarcoma ex

Lymphoma - unique features

- location?

Can spread in the PDL space

--> can easily be mistaken for PARL

- if there is no inflammatory etiology, need to consider lymphoma

Multiple myeloma - unique features

- location?

- shape?

- margins?

- Location: multi-focal

- Shape: round

- Margins: well defined, non-corticated ("punched-out")

--> RL dots throughout

Multiple myeloma ex

Metastatic carcinoma - where is it commonly located?

More likely in the body of the mandible (bc largest vascular supply here)

Metastatic carcinoma - unique features

- Density?

Radiolucent

- but breast and prostate metastases can cause calcification (ex is metatstatic breast cancer)

Metastatic carcinoma - ex

- Ill-defined

- RL

- Irregular borders

- Resorbing roots

How does SHAPE differ for benign vs malignant diseases?

Benign: has some kind of shape

- round

- oval

- undulated

Malignant: no shape

- irregular

How do MARGINS differ for benign vs malignant diseases?

Benign:

- Well-defined, narrow zone of transition

- Smooth or scalloped

- Corticated

- Easy to trace boundary

Malignant:

- Ill-defined, wide zone of transition

- Irregular, ragged

- Moth-eaten

How does DENSITY differ for benign vs malignant diseases?

Benign: can be any of...

- Radiolucent

- Mixed RL-RP

- Radiopaque

Malignant: ALWAYS radiolucent, except...

- Osteosarcoma

- Chondrosarcoma

- Metastatic breast and prostate cancer

How does INTERNAL ARCHITECTURE differ for benign vs malignant diseases?

Benign:

- Unilocular

- Multilocular

Malignant:

- Not loculated

How does EFFECT on CORTICAL BONE differ for benign vs malignant diseases?

Benign:

- Expansion

- Thinning

-- these are slow growing lesions, which gives cortical bone the opportunity to grow and expand, thin cortical boundaries

- Aggressive benign may erode

Malignant:

- Erosion

- Destruction

How does EFFECT on MAXILLARY SINUS differ for benign vs malignant diseases?

Benign:

- Displacement

Malignant:

- Erosion

- Destruction

How does EFFECT on MANDIBULAR CANAL differ for benign vs malignant diseases?

Benign:

- Displacement

- No neurosensory changes

Malignant:

- Invasion

- Destruction

- Anesthesia, paresthesia

How does EFFECT on TOOTH POSITION differ for benign vs malignant diseases?

Benign:

- Displacement

- Impaction

Malignant:

- FLoating teeth

How does EFFECT on TOOTH ROOT differ for benign vs malignant diseases?

Benign:

- No resorption

- Horizontal resorption

Malignant:

- No resorption

- Spiked (vertical) resorption

- Destruction

How does EFFECT ON PDL and LAMINA DURA differ for benign vs malignant diseases?

Asymmetric widening of the PDL space and loss of lamina dura can be a sign of a malignant tumor, such as:

- Osteosarcoma

- Chondrosarcoma

- Lymphoma