Tumor Intro Flashcards
Harington’s Criteria for impending fracture
50% destruction of diaphyseal cortices
50-75% destruction of metaphysis (>2.5cm)
Permeative destruction of the subtroch femoral region
Persistent pain following irradiation
ow to predict risk of impending fracture
significant functional pain
50% coritcal destruction
Staging systems: Harington’s, Mirels
Mirels Criteria
Treatment algorithm for pathologic impending fracture
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
Types of mets with lowest life expectancy after pathologic fracture
lung cancer then melanoma
Treatment of metastatic peritrochanteric and proximal lesions, intracapsular lesions
prophylactic and internal fixation
intracapsular: cemented replacement
Post-op radiation
MSTS staging for osteosarcoma with skip lesions
stage III
Indications for biopsy
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
Fine needle aspiration
providec cytologic (cellular) speciman
used for carcinoma not sarcoma
Core biopsy
tumor structural exam (evaluated cytologic and stromal elements
Sarcoma
Incisional biopsy; excisional
small surgical excision to access tumor
excisional when small, superficial soft tissue masses
Principles of incisional biopsy
longitudinal incision, through one compartment or muscle, meticulous hemostasis (release tourniquet prior to wound closure), bring drain out in line with surgical incision
How does chemo therapy work
induces apoptosis
eliminates micromets in lungs
98% necrosis with chemo is good prognositc sign
Indications for chemo
osteosarcoma (intramedullary and periosteal)
Ewing’s sarcoma/primative neuroectodermal tumor
Malignant fibrous histiocytoma
dedifferentiated chondrosarcoma
Length of chemo admin
Pre-op 8-12 weeks
Post-op 6-12 months
Most common chemo agent
Doxorubicin - cytostatic agent
side effect: CHF
Mechanism of action for radiation
production of free radicals
direct genetic damage
Indications of external beam irradiation
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)
Typical dose of radiation
180-200cGy/Day
Radiotherpy is cumulative
60 Gray: tissue unlikely to heal
Presurgical chemo associated with
more wound complications, less stiffness, smaller radiation field, pseudocapsule formation, shrinks tumor, lower local recurrence rates
What is an enchondroma
benign chondrogenic tumor composed of hyaline cartilage
located in medullary cavity
abnormality of chondroblast function in the physis
Most common bone tumor in hand, 20-50yo
enchondroma
Pathophysiology of enchondroma
chondroblasts and fragments of epiphyseal cartilage escape from physis, displace into metaphysis and proliferate
Associated conditions with enchondroma
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
Treatment of enchondroma
observe but serial radiographs to confirm stability
intralesional curettage and bone grafting - change on xrays, symptomatic, pathologic fracture
Workup of enchondroma
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
What is a periosteal chondroma
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
