Xray Rounds - A Hole in the Bone

1. Xray Rounds - A Hole in the Bone Robbie N Drummond October 31, 2002

2. Overview • Hole found on xray incidental vs presenting symptom • metastases, benign lesions, malignancies : • some basic criteria • the impending fracture

3. What do we do when a test we order brings up an incidental finding • Diagnosis made my combination of primary care physician, radiologist, interventional radiologist, histopathologist, oncologist and orthopod • no definitive pathognomonic findings for specific lesions • our role to initiate diagnosis and slant treatment

4. Is the Lesion infective or neoplastic? • Is the Lesion benign or malignant? • Is it a primary or secondary lesion? • Is the tumour creating or destroying bone? • Is the cortex of the bone intact, broken or eroded

6. Five basic presentations of hole in bone • 1 benign bone tumour • 2 malignant bone tumour • 3 metasastases • 4 non-tumour • 5 infection

7. Age • Osteosarcoma and most malignant tumours are tumours of child hood • Any invasive lesion < 40 Sarcoma • any invasive lesion > 40 Metastasis

8. Location of Common Tumours

9. Benign Tumours • Intact cortex • usually solitary • enlarges by expansion and pressure... Slowly • the margin is sharp geographic • narrow zone of transition • if part of lesion looks benign whole lesion usually is • periosteum not affected

10. Benign Tumour - Chondromyxoid Fibroma

11. Chondromyxoid Fibroma • Uncommon benign tumour • found in proximal tibial metaphyses • sharply marginated lytic zone of destruction • sclerotic rim of bone

12. Malignant Tumours • Moth -eaten leading to permeative pattern • wide zone of transition ill-defined lucencies • small ill-defined lesions • periosteum involved • often soft-tissueinvolvement

13. OsteoSarcoma

14. OsteoSarcoma • Third most common malignancy found in children • 2,500 new cases a year in USA • metaphyses usually in femur proximal tibia • can develop in any bone at any age • mixed sclerotic and lytic lesion • periosteal and soft tissuechanges • almost always solitary

15. X-ray Findings • Sclerosis visible as a cloudy density • variable pattern • permeative moth-eaten pattern • often periosteal involvement as in onion-skin change of • Ewings Tumour

16. Osteomyelitis

17. Metastases • 2,000,000 new cancers a year in USA • half metastasize to bone • only 8,000 new cases of primary bone cancer a year • often metastasis is first presentation of cancer • 50 % of bone gone before found on xray • hallmark multiple bony lesions (found on bone scan)

18. Thyroid Metastasis to Femur (note Codman’s triangle)

19. X-ray Appearance • Metastasis shows poor margination • aggressive looking • variable pattern with soft tissue extension • periosteal reaction • can be lytic, blastic or combined

20. Mets from the Breast

21. Tumours With Predilection for Spread to Bone • Prostate 32% blastic goes to pelvis • Breast 22% lytic prone to fractures long bones • Kidney 16% lytic aggressive long bones • Lung lytic can go to hands and feet • Thyroid usually solitary and lytic

22. Bone Metastases from breast

23. Bone Cysts • Implies hollow often filled with fluid tissue • circumferential thinned and slightly expanded cortex • no periosteal involvement • most are asymptomatic • 2/3 found after pathological fracture • children, boys more than girls • proximal humerus and femur 90% • calcaneus and ileum in adults • multiple cysts rare

24. Xray Appearance • Arise centrally in bone • thinning of overlying cortex • ovoid, symmetrical • most in metaphysis • parallel to axis of bone • geographic and sclerotic margins

25. Treatment • Curretage • insertion of bone chips • methylprednisolone • usually never recur

26. Expanding Aneurysmal Bone Cyst

27. Bone Cyst With Fallen Fragment

28. Benign Bone Cyst

29. The Impending Fracture • Osteolytic more prone than osteoblastic or mixed • areas of high stress - femur humerus • site of endosteal or periosteal resorption with cortical thinning • extending more than 50 -75% of original thickness • interruption in longitudinal or coronal plane > 50% diameter • lesions > 2.5 cm in femur • persistent pain on weight-bearing despite treatment • can be prevented by change in activity, prophylactic pinning, radiation therapy

30. The Impending Fracture

31. The Impending Fracture

32. Mirels Risk Score pathological # • RISK SCORE • VARIABLE 1 2 3 • Site upper limb lower limb peritrochanter • Pain mild moderate severe • Lesion Blastic mixed lytic • Size <1/3 1/3 -2/3 >2/3 (diameter) • fracture likely > 10 unlikely < 7

33. Conclusions • We as primary care physicians should be able to initiate the process of diagnosis in lesions found in bone. • Should be able to differentiate between benign and malignant lesions, primary and secondary lesions and should have some knowledge of non tumourous lesions • should be able to start to advise the patient on the severity of their disease • with the help of the pathological fracture scale decide which patient can benefit from prophylactic surgery