Benign Bone Tumors basics explained well

Benign lesion of bone is defined as one that does not invade surrounding tissue or spread else where in the body. Most benign lesions have limited capacity of recurrence, surgical resection therefore, is often curative. Benign lesions show wide variety of behaviors, some being latent (inactive) i-e;Non ossifying fibroma while others are active with higher risk of recurrence after treatment. i-e;Aneurysmal bone cyst. Intermediate (locally aggressive) can destroy bone and surrounding tissue.i-e Osteoblastoma. Intermediate (rare metastsizing) behave similar to locally aggressive but occasionally show the ability to distant metastasize. i-e Giant Cell Tumor then comes Malignant which are truly aggressive and spread to distant sites.

1. Benign Bone
Tumors
Dr Waris Ali
House Officer
DOST Unit 2

2. Introduction

Abnormal new growth of bony tissue which is uncoordinated, unwanted
and Uncontrollable.
WHO classified bone tumors into
A.Bone forming tumors
B.Cartilage forming tumors
C.Giant Cell tumors
D.Marrow tumors
E.Vascular tumors
F.Tumors like lesions
G.Others

4. Epidemiology
Bone and Soft tissue sarcomas comprise a family of tumors derived from
mesenchymal tissues.
Soft tissues sarcomas occurs more frequently comparatively to bone sarcomas.
The incidence of bone and soft tissue sarcomas is marginally higher in males than
females.
Bone sarcomas demonstrate bimodal distribution in both males and females with
peaks of incidence seen in both teenage/adolescent years and the elderly.
Primary bone tumors may arise in all sites but have preponderance for certain
anatomical locations. More than 60% in long bones of lower limb, 18% bones of
pelvis, 13% upper limb or shoulder girdle.

5. Osteochondroma
Benign, cartilaginous neoplasm derived from an aberrant subperiosteal
nest of physeal cartilage which grows and mature according to normal
endochondral ossification.
Most common benign tumor
Males < 25 years of age
Most commonly occurs in Metaphysis of long bone
Osteochondroma classified in two types;
1.Pedunculated
2.sessile

6. Pathophysiology
Mutations in Exostosin 1 and Exostosin 2 gene
Normally these genes form EXT1 and EXT2
protein which forms Heparin sulphate
Heparin Sulphate regulates growth of growth
plate (Metaphysis)
So Osteochondroma arises at growth plates
forms Lateral bony projection of growth plate
covered by cartilaginous cap

7. It normally presents as painless mass though can cause symptoms
secondary to formation of an overlying bursa due to friction or to activity
related discomfort
Risk of malignant transformation is rare (possibly 1%)
The risk of transformation is dependant on the size , with the cartilaginous
cap being the source of neoplasia in chondrosarcoma.

8. Diagnosis
★X-ray
★Eccentric bony outgrowth from metaphyseal region of
long bone composed of cortical and medullary portions
which are continuous with the cortex and medulla of the
underlying bone.
★Cap not visible (oftenly)
★Usually sufficient

10. Treatment
➢Small asymptomatic lesions— Observation
➢Indications for surgical excision ( Complete excision)
1.Cosmesis
2.Joint dysfunction
3.Fracture
4.Impingement of nerves, vessels ,tendons
5.Malignant Change

11. Osteoma

Benign tumor composed of sclerotic, well formed bone
protruding from the cortical surface of bone.
Most often involves surface of facial bones.
May produce visible swelling.
Associated with Gardner syndrome

12. May bulge into one of the air
sinuses (frontal , ethmoidal etc)
and cause obstruction to sinus
cavity leading to pain.

No treatment is generally
required except for cosmetic
reasons where as a simple
excision is sufficient.

13. Osteoid Osteoma
This is a small benign tumor formed of osteoid and woven bone
surrounded by a halo of reactive bone.
Most common in young patients (Males>females)
Commonly seen in Cortex of long bones particularly proximal
femur.
It is more often diaphyseal than metaphyseal.

14. Presenting feature

Patient presents with bone pain (worse at night), that is
relieved by NSAIDs. (Aspirin only)
When in spine can cause muscle spasm and scoliosis
When lesion near joint can result joint stiffness and
effusion.

15. Diagnosis
Generally confirmed on X-ray.
Tumor is visible as zone of sclerosis
surrounding a radiolucent nidus,
usually less than 2 cm in size.
In some cases, due to excessive
surrounding sclerosis, nidus not seen
plain x-ray, maybe detected on CT
scan.

16. Chondroblastoma
Benign tumor of
childhood. Peak age of
incidence is in teenage
years.
Most common in
epiphysis of long bones
and can cross the physis
Cause pain and
occasionally joint effusion
and stiffness

17. On xray, round or oval lytic lesion ranging on size
from 1 to 7 cm
Cortex maybe expanded but often not breached
Histologically it appears as wet--sawdust with areas
of chondroid matrix ,calcification and hemorrhage.
The presence of chicken wire calcification is
pathognomonic.
Simple curettage with or without bone grafting. En
bloc resection for more aggressive and recurrent
disease

18. Osteoblastoma
Benign tumor consisting of
vascular osteoid and new bone.
Occurs in Jaw and Spine. If
occurs in long bones it occurs in
Diaphysis or Metaphysis but
never in epiphysis.
Occurs second decade of life.
Males>females

19. Patient present with aching pain,
unresponsive to NSAIDs.
Radiologically , it is well defined
radiolucent expansile bone lesion
measuring more than 2 cm.
(2-12cm)

20. Giant Cell Tumor (Osteoclastoma)
Benign but locally aggressive tumor of bone
‘Composed of proliferation of mononuclear
cell with scattered macrophages.
Most common between 20—40 years of age
Typically affects the metaphysis of long
bones

21. Presenting features

Patient will presents with;
Pain
an increasing mass particularly around the knee.
Pathological fracture

22. Plain x ray classically
demonstrate , an eccentric ,
expansile , lobulated lytic
lesion with a narrow zone of
transition
Soap bubble appearance
Cortex may be thinned out or
perforated at places.
Excision or Radiofrequency
done depending upon
location of tumor.

23. Thank you!