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Flashcards in Bone Tumors Deck (17):
1

Osteoma

A tumor-like mass of abnormally dense bone (usually polypoid)

-almost exclusively in the skull (paranasal sinuses and facial bones)
-40-50s

Gardner's syndrome (osteomas, epidermal cysts, fibromatosis and colonic adenomatous polyposis)

2

Osteoid Osteoma
Epidemiology
Xray

A benign, highly vascular, sharply circumscribed osteoblastic proliferation less than 1.5 cm
-single
-intracortical in long bones

Epidemiology:
10-40
M:F 2:1
12y/o with bone pain worse at night relieved by aspirin

X-ray:
Targetoid appearance on X-ray due to pattern of ossification. CT and MRI are far more sensitive
Detectable by bone scan
-Intracortical osteoid osteoma

Histology:
Haphazard bone and osteoid
Rimmed by osteoblasts
Stroma-loose connective tissue, vascular

3

Conventional Osteosarcoma
Osteoblastic Osteosarcoma

High grade sarcoma producing immature osteoid
-painful tender mass
-Often large, metaphyseal centered, fleshy or hard tumor, which can contain cartilage

60% knee, 15% hip, 10% humerus, 8% face

peak age 10-20

Etiology unknown

Histology:
-anaplastic malignant tumor cells

High Grade
Imaging:
lytic blastic lesion with cortical destruction
-sunburst pattern
-periosteal elevation (codman's triangle)

Gross:
metaphysically centered
-fleshy or hard tumor

4

What is a codman triangle?

Osteoblastic OSTEOSARCOMA

triangular shadow between cortex and raised ends of periosteum

(tumor has broken through the cortex and lifted the periosteum resulting in reactive periosteal bone formation)

5

Parosteal Osteosarcoma

Low Grade
Imagining: heavily mineralized mass attached to the cortex with a broad base
-posterior distal femur

Histology:
well formed bony trabeculae in hypocellular stroma
-stromal spindle cells with minimal atypia
-50% cartilaginous differentiation

6

Periosteal Osteosarcoma

Intermediate Grade
Imaging: arising on the surface of the cortex
-displays non homogenous calcified spiculations that are deposited perpendicular to the cortex and overall sunburst appearance

Histopathology:
moderately differentiated chondroblastic osteosarcoma

7

Osteochondroma

An outgrowth of medullary and cortical bone, covered by cartilaginous cap, which projects from the cortical surface of the involved bone

Considered to be a malformation (exostosis) and not a true neoplasm

24% distal femur, 16 humerus, 15% knee

20 year olds

Histology:
fibrous band
cartilage cap
endochondral ossification

8

Osteochonromatosis

Multiple hereditary exostoses
Severe bone deformities with shortening and broadening of tubular bones
Usually manifests by adolescence and ceases in adulthood
autosomal dominant

9

Chondrosarcoma

Malignant cartilage forming tumor
>40 yrs men>women
-painful enlarging masses
-metabolize to lungs, skeleton

-prognosis related to grade, size (5 year 90% grade 1, 43% grade 3)

hip 27%, proximal humerus 19%, 10% ribs, 10% humerus

Histology:
Bone permeation
Bone entrapment

Treat:
surgery
some variants chemotherapy

10

Grade 1 chondrosarcoma

Mildly cellular
Little pleomorphism
myxoid and necrotic areas are sparse or absent
no mitotic activity
metastases are uncommon

11

Grade 2 chondrosarcoma

Moderate cellularity
Frequent myxoid stroma
mild to moderate necrosis
occasional mitotic figures
10-33% rate of metastases

12

Grade 3 Chondrosarcoma

High cellularity
High pleomorphism
Extensively myxoid
Frequent necrosis
Mitosis are readily identifiable
70% rate of metastases even with adequate local control

13

Ewing's sarcoma

a primary osseous neoplasm of small, round, and relatively uniform mesenchymal cells with no microscopic evidence of matrix production
characteristically rich in cytoplasmic glycogen


90% t(11;22)(q24;q12)*** chromosomal translocation
---Fusion EWS/FLI-1 ---overexpression of FLI-1

25% femur
peak 20 y/o

X-ray:
onion skin appearance
-sarcoma invading cortex and adjacent soft tissue

Histology:
-proliferation of small round cell tumor cells
-homer wright rosettes

14

Fibrous dysplasia

a benign intramedullary proliferation of fibrous tissue and bone
osseous component is irregular distributed distributed and is composed of woven bone with NO osteoblastic rimming

most cases single bone but polyostotic in 20%

one of the most common benign fibrous proliferations

22% femur
peak age 15

Radiographically:
well demarcated
expansile lesions
ground glass appearance
conspicuous calcification may be present
erosion through the cortex may occur
prominent periosteal reactivation when fractured

Histology:
curvilinear bone trabeculae

15

McCune Albright's syndrome

-polyostotic fibrous dysplasia (multifocal)
-precocious puberty
-usually unilateral macular pigmented skin lesions (cafe-au-lait spots)
-fibromyxomatous soft tissue tumor
-recurrent fractures may lead to deformities of the lower extremities

Genetics:
1. mutation of GNAS 1 gene that encodes the alpha subunit of the stimulatory G protein coupled receptor GsAlpha
2. albright hereditary osteodystrophy
3. Activating mutations occur post-zygotically replacing the arginine residue amino acid with either a cysteine or histidine
-cells that derive from mutated cells manifest the dysplastic features

16

Giant cell tumor

locally aggressive bone neoplasm characterized by a large number of uniformly distributed OSTEOCLAST LIKE GIANT cells in a background of plump, EPITHELIOID MONONUCLEAR cells

5% of primary bone tumors

24% distal, knee
age peak 25

17

Bone metastases

majority of bone neoplasms
-red marrow of axial skeleton

Adults: prostate, breast, kidney, lung
Children: Neuroblastoma, Wilms tumor, Rhabdomyosarcoma

-Direct extension
-Lymphatic or hematogenous spread
-Intraspinal seeding (batson plexus of veins)

Radiography:
Lytic
-prostaglandins, interleukins, parathyroid hormone related hormones
-osteoclast bone resorption stimulated

Blastic
-sclerotic response

Mixed lytic and blastic