BONES, Joints, Soft Tissues Part 2 Flashcards
(34 cards)
Bone Tumors:
Are most primary or metastatic?
What kinds of bones do we usually see them in?
When are they a/symptomatic?
What are the 3 most common (after hematopoietic)?
Almost always d/t hematopoietic or metastatic tumors (rarely primary)
Most often found in long bones
Benign tumors are often asx and found incidentally; possible pain or pathologic fracture
Most common: Osteosarcoma, chondrosarcoma, Ewing sarcoma
What are 2 bone-forming tumors?
Osteoid osteoma & osteosarcoma
What are 4 cartilage-forming tumors?
Osteochondroma, chondroma, enchondroma, chondrosarcoma
What are 3 tumors of unknown origin?
Ewing sarcoma, giant cell tumor, aneurysmal bone cyst (ABC)
What are 3 lesions simulating primary neoplasms?
Fibrous cortical defect, nonossifying fibroma, fibrous dysplasia
Describe the pain pattern of an osteoid osteoma. Do medication will it respond to? What is this pain due to?
Where do they usually appear and how large are they?
Histo and tx?
Pain that is usually worse at night that responds to aspirin & NSAIDs; excess prostaglandin E2 production by osteoblasts
Seen in males in teens and 20s; 50% appear on femur or tibia
- Strictly <2cm
Central nidus surrounded by osteoblasts; thick rind of reactive cortical bone
- Tx w radiofreq ablation
Compare osteoblastoma to an osteoid osteoma
Location, pain, medications, tx
Osteoblastoma is >2cm, so bigger than osteoma
Involves posterior spine
No bony reaction
Achy pain that does NOT respond to aspirin
Tx: Curetted or excised en bloc
Malignant transformation is rare
What is an osteosarcoma? Are they typically malignant tor benign?
What age do we common see them in?
Malignant mesenchymal cells produce bone matrix; presents as painful enlarging mass
- Most common primary malignant tumor of bone
Bimodal age distribution
- First peak is in males <20yo
- Second peak is in older males w Pagets, bone infarcts, or prior radiation (secondary osteosarcoma)
What do you see on x-ray and what do you see grossly in an osteosarcoma?
X-Ray: Mixed lytic and blastic mass w infiltrative margins
- Codman triangle (elevation of periosteum after bone breaks through cortex) demonstrates aggressive tumor
Gross: Bulky, gritty, grey-white tumors containing hemorrhage & cystic degeneration
- Destroys cortex, spreads to soft tissue, spreads extensively through medullary canal & replaces marrow
What genetic abnormalities do you see with osteosarcomas?
- Rb gene inc risk of sporadic osteosarcoma by 70%
- TP53 Li-Farumani syndrome
- CDKN2A (aka INK4a)
What do you see in microscopy in an osteosarcoma?
“Bizarre giant tumor cells”, large hyperchromic nuclei w abundant mitoses (abn tripolar forms)
- “Lace-like” bone
- May produce cartilage (chondroblastic osteosarcoma if abundant cartilage)
What is an osteochondroma (aka exostiosis)?
What age is this normally seen? What gene abnormalities is this seen with?
Does this normally have a solitary or multiple tumors?
Most common benign bone tumor
Solitary and more common in men in early adulthood
- Younger ages see multiple hereditary exostoses
- EXT1 or EXT2
Multiple hereditary exostosis can progress to chondrosarcoma
What does an osteochondroma (aka exostosis) look like grossly?
Where is it typically located?
Attached to skeleton by bony stalk capped by cartilage; pain if impinge on nerve or fracture
Cartilage is disorganized and undergoes endochondral ossification; medullary cavity of osteochondroma is continuous w bone of origin
Only in bones of endochondral origin
- Metaphysis near growth plate of long tubular bone (esp knee)
What is a chondroma/enchondroma?
What genes are a/w them?
What is tx?
Benign hyaline cartilage, solitary metaphyseal lesion tubular bones of hands and feet
- If it’s within medullary cavity it is an enchondroma
- If it is on the surface it is a subperiosteal or juxtacortical chondroma
- IDH1 & IDH2
Tx: Observation or curettage
What imaging do you see in an chondroma/enchondroma?
Well-circumscribed nodules of hyaline cartilage (lucency) w central irregular calcifications, a sclerotic rim, and an intact cortex
What is Ollier syndrome?
What is Maffucci syndrome? What does this inc the risk for?
Ollier: Multiple chondroma/enchondromas, not hereditary
Maffucci: Multiple chondroma/enchondroma plus hemangiomas; inc risk of chondrosarcoma & other malignancies; not hereditary
Both have inc cellularity and atypia
What is a chondrosarcoma? What patient population do we often see it in? Where in the body do we see it?
Second most common malignant matric producing tumor of bone (osteosarcoma is first)
- M:F=2:1; usually 40s or older
- Axial skeleton (pelvis, shoulders, ribs)
- 15% are secondary that arise from enchondromas or osteochondroms
What are some characteristics of a chondrosarcoma? Genes?
Invade locally, painful enlarging mass, may metastasize
- Grade 3 often spread hematogenously esp to the lungs
- IDH1 & IDH2
What does imaging show in a chondrosarcoma?
Calcified matrix appears as foci of flocculent densities
What are the grades and types of chondrosarcomas and what is the correlation between histologic grade and behavior?
Direct correlation b/w grade and behavior; graded 1-3 based on cellularity, cytologic atypia, mitotic activity
- Conventional: Nodules of glistening grey-white, translucent cartilage
- Dedifferentiated: Low grade w a high grade component, no cartilage
- Clear cell: Numerous osteoclast-type giant cells & intralesional bone formation
- Mesenchymal: Islands of well-differentiated hyaline cartilage surrounded by sheets of primitive appearing small round cells
What is tx for a chondrosarcoma?
Wide surgical excision for conventional. Mesenchymal & dedifferentiated require excision & adjuvant chemotx bc more aggressive
What are Ewing Sarcoma Family Tumors?
- What are common ages and populations we see it in?
- What is the cell appearance?
- Where in the body do these present?
- Clinical sx?
- Often seen in Caucasian populations less than 20 years old
- Small blue round tumor or primitive round cells; neural differentiation (PNET)
- Reactive bone in “onion-skin” on xray
- Diaphysis of long bones esp femur and the flat bones of the pelvis
- Painful enlarging mass that is often tender, warm, and swollen; mimics infection
- What genes do we see in Ewing Sarcoma Family Tumors?
- Histo?
- Gross appearance?
- Tx?
- Important prognostic finding?
- EWSR1 gene on chromosome 22 w partner of FLI1 on chromosome 11; fusion of these two leads to uncontrolled growth & abn differentiation
- Soft, tan-white, w areas of necrosis and hemorrhage
- Homer-wright rosettes
- These are aggressive malignancies best txx w chemo followed by surgical excision w or w/o radiation
- The amount of chemo-induced necrosis is an impt prognostic finding (the more necrosis the better, indicative of sensitivity to tx)
Giant cell tumor:
What is an osteoclastoma? Benign or malignant? What is a ddx for this tumor?
What age do we normally see this?
Where in body do we see?
Multinucleated osteoclast-type giant cell; neoplastic cells are primitive osteoblast precursors expressing RANKL which promotes proliferation & differentiation of osteoclasts
- In ddx must consider brown tumor of hyperPTism
Common in 20-40yos; benign but locally aggressive
Arises in epiphyses
- Knee: Distal femur & proximal tibia gives arthritis-like sx
