Malignant bone tumours

Question 1

systemic symptoms

Answer 1

weight loss loss of appetite fatigue more likely in patients over 60

Question 2

red flags that there is metastatic cancer affecting bone

Answer 2

constant pain - may be severe and is usually worse at night systemic symptoms unexplained skeletal pain in over 60s - more likely to develop malignant cancer unexplained skeletal pain in under 25s - shouldn’t happen

Question 3

characteristics of primary malignant bone tumours

Answer 3

can occur in children not uncommonly misdiagnosed as muscle pain - presentation is often late so metastases have occurred

Question 4

X-ray signs of a primary malignant bone tumour

Answer 4

substantial ill-defined bone swelling - urgent investigation and referral aggressive and destructive signs cortical destruction periosteal reaction - raised periosteum producing bone new bone formation - sclerosis as well as lysis from destruction extension into surrounding soft tissue envelope

Question 5

what is osteosarcoma?

Answer 5

the most common primary malignant tumour producing bone pretty aggressive

Question 6

who gets osteosarcoma?

Answer 6

younger - adolescence, early adulthood proximal femur, proximal humerus and pelvis are the common sites

Question 7

what is the metastatic spread of osteosarcoma?

Answer 7

haematogenous not lymphatic spread 10% have pulmonary metastases at diagnosis

Question 8

what is the treatment for osteosarcoma?

Answer 8

it is not radiosensitive but adjuvant chemotherapy can prolong survival

Question 9

what is chondrosarcoma?

Answer 9

a cartilage producing bone tumour mainly in the older age group - 45 can be very large and slow to metastasise normally in the pelvis/proximal tumour

Question 10

how is chondrosarcoma managed?

Answer 10

not radiosensitive and unresponsive to adjuvant chemotherapy

the prognosis depends on histological grading - majority are low grade

Question 11

how do you grade a sarcoma?

Answer 11

the degree of differentiation/proliferation (miotic count)

presence of coaguative necrosis

Question 12

what are fibrosarcoma and malinant fibrous histiocytoma

Answer 12

fibrous malignant primary bone tumours

In abnormal bone e.g. bone infarct, fibrous dysplasia, post irradiation or Paget’s disease

fibrosarcoma occurs in adolescents and young adults

Question 13

what is Ewing’s sarcoma?

Answer 13

a malignanr tumour of the primitive cells in the marrow

the 2nd most prevalent bone tumour

has the poorest prognosis

Question 14

how does ewing’s sarcoma present?

Answer 14

in 10-20 year olds

symptoms (associated):

fever

raised inflammatory markers

warm swelling

may be misdiagnosed as osteomyelitis

Question 15

how is ewing’s sarcoma treated?

Answer 15

radiosensitive and chemosensitive

Question 16

how are primary bone tumours managed?

Answer 16

staging investigations

bone scan

CT chest

MRI & CT - to determine the extent of the tumour and muscle nerve and vessel involvement

biopsy - histological diagnosis & grading prior to definitve surgery

surgery: remove the tumour and surrounding tissue

amputations used to be common

limb salvage surgery since the chemo’s better now

wide margin 3-4cm

biopsy tract removed with the tumour

joints involved need reconstructed

adjuvanr chemotherapy and radiotherapy:

neo-adjuvant chemotherapy (prior) - can improve survival

80% survival rate

Question 17

what is lymphoma?

Answer 17

cancer which begins in the lymphocytes

round cells of the lymphocytic system/ macrophages

Question 18

primary lymphoma in the bone

Answer 18

non-hodgkins lymphoma from marrow

pelvis and femur are common sites

treatment - surgical resection

Question 19

Metastatic lymphoma

Answer 19

any lymphoma can metastasise to the bone (20%)

treatment:

splenomegaly

radiotherapy or chemotherapy

survival less than 2 years

Question 20

What is myeloma?

Answer 20

malignant B cell proliferation from the marrow

solitary lesion = plasmacytoma

multiple lesions = multiple myeloma

Question 21

how does myeloma present?

Answer 21

in 45-65

weakness

back pain

bone pain

fatigue

weight loss

may have marrow suppression - anaemia,recurrent infection

may present with pathologic fracture

Question 22

how is myeloma diagnosed?

Answer 22

plasma protein electophoresis - high paraprotein levels

early morning urine collection - Bence Jones protein assay

x rays

lytic lesions - not usually an osteoblastic response to the osteoclastic bone reabsorptoin - metastases may not be detected on bone scan

Question 23

How is myeloma treated?

Answer 23

plasmacytoma = radiotherapy

multiple myeloma = chemotherapy (5yrs< 30%)

Question 24

bones most frequently involved in metastatic bone cancer

Answer 24

vertebra

pelvis

ribs

skull

humerus

long bone of lower limb

Question 25

type of metastases from breat carcinoma

Answer 25

blastic (sclerotic/ lytic metastases

mean survival 24-26 months

Question 26

type of metastases from prostate carcinoma

Answer 26

sclerotic metastases

osteoblastic activity - pathologic fractures are more likely to heal

radiotherapy and hormone manipulation - reduce fracture risk

survival with prostatic bone metastases around 45% at 1 year

Question 27

type of metastases from lung carcinoma

Answer 27

lytiv bony lesions

mean survival 6 months with bone metastases

Question 28

type of metastases from renal cell carcinoma

Answer 28

large, very vascular lytic “blow out” bony metastases

can bleed tremendously with biopsy or surgery

single bone metastasis and primary tumour amenable to resection (nephrectomy) - surgery

multiple bone metastases mean survival 12-18 months

Question 29

symptoms of bone metastases

Answer 29

pain - initially can be misdiagnosed as muscle pain

any pain with red flags should be investigated at least by x ray

pathological fracture

Question 30

investigations if bone lesion found on x-ray in over 45

Answer 30

primary bone tumour needs to be excluded - bone scan, MRI

bone scan - exclude primary bne umour, demonstrate extent of metastases

if multiple - primary tumour should be found

breast exam

PR exam

CXR - pulmonary lesion

Blood tests:

serum calcium - hypercalcaemia

LFTs

plasma protein electropheresis - myeloma

FBC

U&E

Question 31

what are the indications that there is a risk of impending fracture because of a bone metastases

Answer 31

very painful lesions - especially on weight bearing

lesions occupying >50% of the diameter of the bone

cortical thinning

“at risk areas” - subtrochanteric area of the femur

skeletal stabilisation/ joint replacement should be done

Question 32

when should surgery be done for metastases

Answer 32

fractures/impending fractures - stabilization using long ords (intramedullary nails)

destruction of joint (acetabulum, femoral head) - joint replacement

surgery has a high risk of DVT and prophylaxis must be given

chemo and radiotherapy after surgery

Question 33

how should painful lesions not to be at risk of impending fracture be managed?

Answer 33

bisphosphates and radiotherapy

Question 34

spinal cord compression - advanced spinal metastases

Answer 34

radiotherapy or surgical decompression (anterior or posterior)