Tumor Intro

Question 1

Harington’s Criteria for impending fracture

Answer 1

50% destruction of diaphyseal cortices

50-75% destruction of metaphysis (>2.5cm)

Permeative destruction of the subtroch femoral region

Persistent pain following irradiation

Question 2

ow to predict risk of impending fracture

Answer 2

significant functional pain

50% coritcal destruction

Staging systems: Harington’s, Mirels

Question 3

Mirels Criteria

Answer 3

Question 4

Treatment algorithm for pathologic impending fracture

Answer 4

Tissue diagnosis with biopsy if primary

Radiation of low Mirels Score

Surgical fixation: do not proceed until primary neoplasty of bone has been ruled out

Post-op radiation: decreases pain, slows progression, treat remaining tumor

Question 5

Types of mets with lowest life expectancy after pathologic fracture

Answer 5

lung cancer then melanoma

Question 6

Treatment of metastatic peritrochanteric and proximal lesions, intracapsular lesions

Answer 6

prophylactic and internal fixation

intracapsular: cemented replacement

Post-op radiation

Question 7

MSTS staging for osteosarcoma with skip lesions

Answer 7

stage III

Question 8

Indications for biopsy

Answer 8

agressive bone or soft tissue lesions

soft tissue lesion >5cm, deep to fascia or overlying bone/NV structures

unclear dx in symptomatic patient

solitary bone lesion in patient with history of carcinoma

Question 9

Fine needle aspiration

Answer 9

providec cytologic (cellular) speciman

used for carcinoma not sarcoma

Question 10

Core biopsy

Answer 10

tumor structural exam (evaluated cytologic and stromal elements

Sarcoma

Question 11

Incisional biopsy; excisional

Answer 11

small surgical excision to access tumor

excisional when small, superficial soft tissue masses

Question 12

Principles of incisional biopsy

Answer 12

longitudinal incision, through one compartment or muscle, meticulous hemostasis (release tourniquet prior to wound closure), bring drain out in line with surgical incision

Question 13

How does chemo therapy work

Answer 13

induces apoptosis

eliminates micromets in lungs

98% necrosis with chemo is good prognositc sign

Question 14

Indications for chemo

Answer 14

osteosarcoma (intramedullary and periosteal)

Ewing’s sarcoma/primative neuroectodermal tumor

Malignant fibrous histiocytoma

dedifferentiated chondrosarcoma

Question 15

Length of chemo admin

Answer 15

Pre-op 8-12 weeks

Post-op 6-12 months

Question 16

Most common chemo agent

Answer 16

Doxorubicin - cytostatic agent

side effect: CHF

Question 17

Mechanism of action for radiation

Answer 17

production of free radicals

direct genetic damage

Question 18

Indications of external beam irradiation

Answer 18

Definitive control (primary malignant bone tumors): ewing, primary lymphoma of bone, hemangioendothelioma, solitary plasmacytoma of bone

Adjuvent to surgical excision: soft tissue sarcomas pre or post

Palliative care and impending fracture: metastatic bone disease (after fixation, prostate, BC)(GI and renal tumors are not radiosensitive)

Question 19

Typical dose of radiation

Answer 19

180-200cGy/Day

Radiotherpy is cumulative

60 Gray: tissue unlikely to heal

Question 20

Presurgical chemo associated with

Answer 20

more wound complications, less stiffness, smaller radiation field, pseudocapsule formation, shrinks tumor, lower local recurrence rates

Question 21

What is an enchondroma

Answer 21

benign chondrogenic tumor composed of hyaline cartilage

located in medullary cavity

abnormality of chondroblast function in the physis

Question 22

Most common bone tumor in hand, 20-50yo

Answer 22

enchondroma

Question 23

Pathophysiology of enchondroma

Answer 23

chondroblasts and fragments of epiphyseal cartilage escape from physis, displace into metaphysis and proliferate

Question 24

Associated conditions with enchondroma

Answer 24

Olliers disease (multiple enchondromatosis), enchondromas throughout long bones

Maffucci’s syndrome - multiple enchondromas and soft-tissue angiomas, enchondromas markedly expand the bone, angio are round calcified phelboliths, high rate of malignant transformatin

Question 25

Treatment of enchondroma

Answer 25

observe but serial radiographs to confirm stability

intralesional curettage and bone grafting - change on xrays, symptomatic, pathologic fracture

Question 26

Workup of enchondroma

Answer 26

xray - popcorn stippling, arcs, whorls, rings, minimal erosion, may have cortical expasion in hands and feet or lytic appearance

skeletal survay and bone scan in polystotic disease suspected

core needle biopsy if bone scalloping or lysis

Question 27

What is a periosteal chondroma

Answer 27

rare benign chondrogenic lesion on surface of long bones

10-20 yo, most proximal humerus

painful due to irritation of tendons

tx: marginal excision including underlying cortex