Rad 3 week 1

What are the 3 most important considerations for bone tumor identifications?*

Pain

Age

Location

What is the most common cause of metastatic tumors?

Primary soft tissue tumors

What are the considerations for tumors

number of lesions

site

location

cortex

periosteum

soft tissue mass

What is normally indicated by a narrow zone of transition?

Bengin lesion

What is normally indicated by a wide zone of transition?

Malignant and/or aggressive lesion

What is indicated by multiple lesions?

Metastasis

Multiple myeloma

What does a narrow zone of transition mean?

Well-defined lesion (obvious border between pathologic and healthy bone)

What does a wide zone of transition mean?

Ill-defined lesion

Where do chondroblastomas form?

Epiphyses

Apophyses

What is the term for a growth extending off the cortex?

Exostosis

What is the term for a growth in the cortex?

Cortical

What is the term for a growth offcenter in the middle of the bone?

Eccentric

What is the term for a growth centred in the marrow?

Centralized

What does an intact cortex indicate?

Benign lesion

What does a broken cortex indicate?

Aggressive lesion

What is contained in the outer layer of the periosteum?

Blood vessels

attachment of tendons and ligaments

What is contained in the inner (cambium) layer of the periosteum?

osteoblastic and clastic activity

What are the aggressive perisoteal reactions?

Laminated

Spiculated

Codman's triangle

What are the AKA of speculated periosteal reactions?

Sunray / Sunburst

What is the only benign periostea reaction?

Solid

What are the AKAs of laminated periosteal reaction?

Onion skin

Lamellated

Multi-layered

What does the periosteal reaction tell you?

The rate of growth of the lesion

What type of patient usually has periosteal responses?

younger patients due to active bone growth

T or F: Soft tissue masses are more commonly seen in metastatic tumors than primary tumors

False (more common in primary tumors)

What is the term for a well-defined area of radiolucency within bone, without a sclerotic border?

Geographic lesion

What is indicated by a geographic lesion?

Benign lesion

What is the term for large areas of destruction with ragged borders?

Moth-eaten

What is the term for small, ill-defined areas through marrow space?

Permeative

What do moth eaten and permeative appearances indicate?

Aggressive lesion

T or F: You can have a benign, expansile lesion

True

What terms can be used to describe expansile tumors?

Bubbly

Trabeculated

Loculated

Chambered

What are the top 2 Ddx for multiple lytic lesions?

Metastasis

Multiple Myeloma

What are the 3 most important parts of information to form a ddx

age, pain and location

What is the most common malignant tumor of the skeleton?

Metastasis (70%)

What age group is most affected by metastasis?

40+ yo

What is the most common cause of metastasis under 5 yo?

Neuroblastoma

What is the most common cause of metastasis from 10-20 yo?

Ewing's sarcoma

What is the most common cause of metastasis over 20 yo?

Hodgkin's lymphoma

Which gender is more affected by metastasis?

Male

What are the classic signs of metastasis?

Weight loss

Pathologic fracture

Pain worse at night

Intractable pain (can't be relieved)

T or F: Metastatic carcinoma is more frequently asymptomatic

True

What are the methods of metastatic spread?

Direct extension

Lymphatic channels

Hematogenous dissemination

What is the term for malignancy spreading to an adjacent bone?

Direct extension (contiguous)

What is the most common spread of metastasis?

Hematogenous spread

Why are lymphatic channels an uncommon method of bone metastasis transmission?

There are no lymphatic channels in bone marrow

What is the most common type of metastatic lesion?

Lytic (75%)

What is the term for destruction exceeds repair and radiolucent areas appear as hole sin the bone

lytic lesions

What is the term for reactive repair response of local osteoid tissue to the presence of tumor?

Blastic lesion

What is the name sign of blastic metastasis in the pelvis?

Multiple snowball appearance

T or F: Blastic metastasis has a better prognosis than lytic

True

What % of metastasis is mixed?

10%

What are the 3 most common origins of blow out metastasis?

Lungs

Thyroid

Kidney

What is the appearance of blow out metastasis?

Bubbly and expansile

What are the 2 ddxs for blow out metastasis?

Solitary plasmacytoma

Giant Cell Tumor

What is the most common primary malignancy for lytic mets in men?

Lungs cancer

What is the most common primary malignancy for lytic mets in women?

Breast cancer

What is the most common primary malignancy for blastic mets in men?

Prostate cancer

What is the most common primary malignancy for blastic mets in women?

Breast cancer

T or F: Periosteal response is more common with metastasis than primary tumors

False (more common in primary)

What length of tumor indicates a primary tumor rather than metastasis?

> 6 cm (long lesion)

T or F: Expansile lesions are more commonly primary than metastatic

True

What is the gold standard for diagnosing a cancer cell type?

Biopsy

T or F: Primary lesions, more commonly, than metastasis have a soft tissue mass

True

What is the typical size of a metastatic lesion?

2-4 cm

What type of mets is the exception to most of the characteristic features of mets?

Blowout mets

T or F: Labs are often useful for diagnosis of mets

False (often non-specific)

How much bone must be lost before it appears osteopenic on x-ray?

30-50%

What is the benefit of X-ray over CT for cancer?

CT may overlook subtle areas of marrow replacement

What is CT most useful for in cancer cases?

Localizing biopsy sites

What are the AKAs of bone scan?

Nuclear imaging

Bone scintigraphy*

DEXA

What % of skeletal mets can be seen on bone scan?

85%

What isotope is used in bone scans?

Technetium-99m-methylene disphosphonate (Tech-99)

What % of bone loss can be seen on bone scan?

3-5%

What do bone scan hot spots indicate?

Increased metabolic activity

What colour are bone scan hot spots?

Dark

What is the gold standard for evaluating the entire skeleton for multiple lesions?

Bone scan

What part of the skeleton is tracer uptake greatest in bone scan?

Axial skeleton

What sites have the most symmetrical tracer uptake in bone scan?

Acromial and coracoid processes

What is phase 1 of a bone scan

Flow phase - first 60 seconds

show difference in vascularity

What is phase 2 of a bone scan

Pool phase - 2-9 minutes

pool in the difference in vascularity permeability

What is phase 3 of a bone scan

Delayed phase - 2-3 hours

increase in metabolic activity in bone

T or F: Bone scan is very specific, but not very sensitive

False (very sensitive, not very specific)

What is the triad of brochogenic metastasis?

Symmetric arthritis (most common in the knee)

Metaphyseal/diaphyseal periostitis

Clubbing of the fingers

What % of skeletal mets is detected by MRI?

91%

What is the most sensitive imaging to detect metastatic disease within an examined region?

MRI

What colour is cancerous marrow signal on T1 MRI?

Dark (normally light)

What does STIR stand for?

Short tau inversion recovery; fat sat

What colour is metastasis on STIR sequence?

Hyperintense (light)

What contrast agent is most commonly used for MRI?

Gadolinium

Where does gadolinium accumulate?

High vascular areas

What are the most common locations of skeletal mets?

Axial skeleton (40%)

Pelvis (12%)

Skull (10%) - mostly lytic

Ribs and sternum (28%)

proximal long bones (10%)

What is the name sign of lytic mets in the skull?

Swiss cheese appearance

T or F: Acral mets is common

False (very rare)

What is the most common cause of acral metastasis?

Bronchogenic carcinoma

What is the earliest sign of lytic mets in the vertebral body?

subtle loss of density in contrast to adjacent vertebral bodies

What is the appearance of a pathological compression fracture on x-ray?

Loss of anterior and posterior vertebral body height

What are the AKAs of pathological compression fracture?

Vertebra plana

universal compression fracture

Pancake vertebra

What are the causes of pathological compression fracture from most to least likely?*** (DONUT QUESTION)

Osteoporosis

Metastasis

Multiple myeloma

What is the finding of the vertebral endplate in metastasis?

Pathologic schmorl's nodes

What is the Ddx of pathologic schmorl's nodes?

Scheurmann's disease