TOPIC OUTLINE

I. Bone Tumors

A. Modalities

B. Diagnostic CriteriaII.SummaryTransers Note: Dr. Galsim didnt give us a copy of his PPT so we used the pictures from the 2016 buddy CD files and from the internet. Happy studying! :)

Legend: From PPTMentioned by lecturerI. BONE TUMORS Seldom encountered by clinicians Important to recognize them in future clinical practiceA. MODALITIES

Radiographic findings may not allow precise diagnosis

Provide reliable information on aggressiveness or rate of growth of bone tumors Aggressive ( malignant; non-aggressive ( benign; except:

Aneurysmal bone cyst & osteomyelitis aggressive but benign

Ameloblastoma non-aggressive but malignantX-RAY

Conventional 2D imaging modality

Sensitive technique

Assesses the aggressiveness of the lesion, based on certain criteria given (ex. non-aggressive lesions are benign)

Cannot provide a histological diagnosis 50% of bone matrix must be destroyed to be observed

ULTRASOUND Used for joint diseases (ex. effusion, edema)

Not very useful unless with total destruction of the bone cortex

Often used in MSK for assessment of muscles, tendons, & soft tissueCT

Used for cortical lesions Determine calcified lesions (appear hyperdense)

Useful for determining the extent of the tumor, for its staging, and for detecting metastasis (contiguous or distal)

MRI Used for marrow, medullary cavity lesions, & soft tissue Gives superior soft tissue resolution

Like CT, useful for determining tumor extent, staging, and metastasis

BONE SCAN Assesses bone metastasis Unlike plain radiographs, bone marrow destruction can be as low as 5 to 20% to be detected

Determines level of metabolic activity

Very sensitive but non-specific

False positive: degenerative, superimposed inflammatory process, or from previous thoracotomyPET

Able to assess functionality Expensive, but when combined with CT/MRI, extent or status of the lesion becomes easily definedb. diagnostic criteria

AGE Jack Edeiken

Bone radiologist Evaluated 4000 malignant bone tumors, which could be diagnosed correctly 80% of the time just by using the patients ageInfantMetastatic neuroblastoma

1st to 2nd decadeEwings tumor

2nd to 3rd decadeOsteosarcoma

40 years old and aboveMetastatic carcinoma, multiple myeloma, and chondrosarcoma

Table 1. Most common bone tumors based on age groups.LOCATION IN LONG BONE Parts of a long bone

Epiphysis one end of the long bone

Metaphysis growth plate region

Diaphysis shaft

Others: epiphyseal plate, apophysis, articular cartilageEpiphysisFour most common conditions: Chondroblastoma (with calcification in matrix) child

Giant cell tumors adult Osteomyelitis fungus, TB Aneurysmal bone cysts/ABC

MetaphysisCharacterized by high vascularity and metabolic activity, so most bone lesions (including infections) occur in this regionMost benign and malignant bone tumors such as

Osteochondroma (benign) Osteosarcoma (malignant) Chondrosarcoma (malignant)

DiaphysisComposed of yellow or red marrowApart from cortical lesions, there are lesions of marrow origin

Round cell tumors such as Ewings sarcoma, reticulum cell sarcoma (lymphoma of bone), and multiple myeloma (plasma cell origin)

Table 2. Long bone locations and associated bone lesions.

Figure 1. Frequent sites of bone tumors.

Figure 2. Epiphyseal tumor with metaphyseal involvement. Pointed structure is a giant cell tumor (GCT) in the upper right tibia (left). Other examples of GCT (upper and lower right).

Figure 3. Metaphyseal tumor (but extends to the diaphysis, so more of metadiaphyseal involvement). Pointed structures are osteosarcomas, examples of cloudy, amorphous matrices.

Figure 4. Diaphyseal involvement. Ewings sarcoma in young patient, then multiple myeloma older patients (left). Enchondroma with pathologic fracture (right).TUMOR MARGINS Pattern of bone destruction/zone of transition Most reliable plain film indicator for aggressive vs. non-aggressive lesions Zone of transition (ZOT) border of lesion with normal bone Narrow ZOT well-defined; mostly non-aggressive Wide ZOT ill-defined or imperceptible margin; mostly aggressive Pattern of bone destruction Types of margins:

1. Geographic

Well-defined or narrow ZOT

Sometimes with sclerotic margin If bone has time to form sclerosis, this is indicative of its non-aggressiveness! Least aggressive, and with most benign bone tumors2. Moth eaten

Less well-defined

Multiple small lucencies, with tendencies to coalesce if numerous More aggressive, and mostly malignant

Ex. multiple myeloma3. Permeative Poorly defined or wide ZOT

Imperceptibly merge with normal bone True size larger than seen on radiograph

Ex. Ewings sarcoma

Figure 5. Different patterns of bone destruction.

Figure 6. Geographic lytic lesion in the metadiaphysis of the humerus (leftmost). Moth eaten appearance of multiple myeloma (middle). Permeative bone destruction (rightmost). Figure 7. Geographic bone destruction.

Figure 8. Moth-eaten skull. Similar appearance in hyperparathyroidism wherein bone resorption is promoted, resulting in osteopenia (left). Moth-eaten lesions seen in multiple myeloma (right).

Figure 9. Permeative bone lesion with a wide ZOT. Lower zone appears more lucent than upper.PERIOSTEAL NEW BONE FORMATIONWhen there is a tumor or infection, the endosteum and periosteum react and try to contain the lesion.

Figure 10. Types of periosteal reaction from left to right: (1) Lamellar, (2) Laminated/Layered, (3) Sunburst, and (4) Codmans Triangle.1. Lamellar

Most common form of bone formation

With single layer of new bone formation

Uniform thickness (>1mm) and density

Hallmark of a benign lesion (no surgical intervention necessary) Ex. Non-ossifying fibroma benign, should not be touched Ex. Chronic osteomyelitis thats healed However, osteoid osteoma is a benign lesion, but requires intervention/enucleation because it causes the patient pain.

Figure 11. Lamellar periosteal reaction.2. Laminated or layered

Multiple layers of periosteal reaction almost parallel to long axis of bone

Onion skin appearance

Result of alternating tumor growth and attempt of bone to control tumor growth

Periosteal reaction is not enough to contain the process

Aggressive lesions

Figure 12. Laminated/layered periosteal reaction.3. Sunburst or hair-on-end

Periosteal reaction almost perpendicular to long axis of bone

Aggressive lesions

Tumor is too fast ( periosteal reaction cant catch up! Sharpeys fiber

Bones failed attempt to contain the growing lesion

Formation is pulled and grows outward with the tumor

Example: osteosarcoma, Ewings sarcoma

Figure 13. Osteosarcoma. With typical sunburst pattern.4. Codmans triangle

Non-specific findings seen in both tumors and infections

Three sides are observed:

Bone

Periosteal reaction Tumor

Can be mistaken for inflammatory exudates infiltrating the cortex, appearing as an abscess at the bottom

Figure 14. Codmans Triangle (purple arrow). Sunburst (red arrow).TUMOR MATRIX FORMATIONWhen the tumor advances, soft tissue pathology can be seen.

With calcifications osteoid or chondroid

Without calcification long spectrum of sarcomas & malignanciesWe should know how to differentiate between osteoid and chondroid.

1. Chondroid

Punctate, popcorn-like, flecks, rings, or arcs of calcific density Examples: Chondrosarcoma recurrence in bony pelvis

Intramedullary chondrosarcoma in the distal femur

Popcorn-like inferior pubic rim

Figure 15. Chondroid matrix. High grade chondrosarcoma of the left iliac bone. Soft tissue extension seen on axial T2-weighted MRI.

Figure 16. Chondroid matrix.2. Osteoid Cloudlike or amorphous (chalk-like appearance)

No particular shape May also present with calcifications

Figure 17. Osteoid matrix in osteosarcoma (left). Osteoid osteoma (right).

Figure 18. Intramedullary osteosarcoma of distal femur with large soft tissue mass exhibiting classic osteoid matrix.

II. SUMMARYKnowledge of the radiologic diagnostic criteria for bone tumors would enable a physician to accurately characterize the lesion, determine its aggressiveness, and come up with a short list of differential diagnoses.What determines how the lesions appear?

When cells are activated, it can be either: Blastic osteoblasts form more bone (ex. osteosarcoma)

Lytic osteoclasts stimulated

Matrix of tumor

END OF TRANSCRIPTION

GREETINGS!

Avie:

Thank you for taking pictures, Trish!Hello, Block 8! Lets eat more of these please :Q

Yanyan:

Hey Block 8! Hurrah for our very first block bonding activity last Friday! Also, lets all attend the TRP practices! TWTh at Calderon Hall and Student Lounge! Kamon mamooon! LETS WIN IT THIS YEAR!!! \:D/