Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Orthopaedics PPT 5 Benign Bone Tumour Lecture Notes
BENIGN BONE
TUMOURS
CLASSIFICATION
1.BONE FORMING TUMOURS.
a] BENIGN b]MALIGNANT.
. osteoma . Osteosarcoma
. osteoid osteoma . juxta cortical
. Osteoblastoma osteosarcoma
. periosteal
osteosarcoma
2.CARTILAGE FORMING TUMOURS
a] BENIGN b]MALIGNANT
. Chondrosarcoma
. osteochondroma
. chondromyxoid fibroma
. chondroblastoma
3.GAINT CELL TUMOUR
a] classical benign type (locally aggressive)
b] malignant GCT
4.MARROW TUMOURS
a] ewings sarcoma
b] myeloma
5.VASCULAR TUMOUR
A] benign b] malignant
. haemanigoma . angiosarcoma
. lymphangioma
. glomus tumour
6. CONNECTIVE TISSUE TUMOURS
A] benign
B] malignant
. desmoplastic fibroma . fibro sarcoma
. lipoma . Liposarcoma
7.OTHER TUMOURS.
a] chordoma
b] adamantinoma
c] neurofibroma
8.TUMOR LIKE LESIONS
a] solitary bone cyst
b] aneurysmal bone cyst
c] ganglion
d] non ossifying fibroma
e] fibrous dysplasia
f] eosinophilic granuloma
g] myositis ossificans
h] brown tumor of hyper parathyriodism.
Radiographic Features of the Various
Tumors
Benign:
well circumscribed, narrow zone of transition, no periosteal
reaction, sclerotic border.
Benign Aggressive:
expansion, thinning of cortex, usually lytic, +/- periosteal
reaction, +/- narrow zone of transition.
Malignant:
++++periosteal reaction, large zone of transition, permeative,
moth eaten.
BENIGN TUMOUR
BENIGN AGGRESSIVE TUMOUR
MALIGNANT TUMOUR
Age of Tumors
<20y - Osteogenic Sarcoma, Ewings.
20-40y - GCT, Chondrosarcoma, MFH, Lymphoma
In 60 y - Mets, Myeloma, Chondrosarcoma, late
Osteogenic sarcoma, MFH, Fibrosarcoma.
Sites of Tumors
Diaphyseal: Ewings, Osteoid Osteoma, Mets,
Adamantinoma, Fibrous Dysplasia
Epiphyseal: Chondroblastoma, GCT,
Metaphyseal: Osteosarcoma, bone cysts.
OSTEOID OSTEOMA
This is benign osteoblastic tumor with a well
demarcated nidus of less than 1 cm
surrounded by a distinct reactive bone
INCIDENCE: 2.6% of all primary bone tumors
Age : 10-25 yrs
Sex: M:F::2:1
Site : long bones usually tibia and femur more
commonly affected
Clinical feature:
.vague and intermittent pain more at night
. pain relived by aspirin.
. mild swel ing , tenderness present
X-ray : central lucency surrounding the nidus with or without
dense calcified center, which is surrounded by reactive
sclerosis
Treatment : wide enblock resection with removal of
surrounding sclerotic bone .
BENIGN OSTEOBLASTOMA
A benign osteoblastoma is an uncommon vascular
osteoid and bone forming tumor .
It is very slow growing and characterized by
absence of any reactive perifocal bone formation.
INCIDENCE:0.8% of all primary tumors.
AGE:10-20yrs.
SITE: vertbra ,flat bones usually.
Microscopy - A well circumscribed tumor when it is expanded it is
delimited by a shell of cortical new bone. Dense sheets of osteoid
and irregularly calcified new bone with intervening vascularized
background of osteoblastic connective tissue stroma. Giant cells may
be present.
q Clinical Features: Pain, Swelling, Rarely As
Fractures
X RAY : Lesion is well circumscribed, radiolucent and expansile in
fusiform fashion . Cortex is preserved with or without calcification.
Malignant transformation has been reported.
Treatment:
Small to moderate ? Curretage and bone grafting
Recurrent - enbloc marginal excision.
ENCHONDROMA
This is a benign cartilaginous tumor centrally located in phalynx.
INCIDENCE:3% of all bone tumors.
AGE:10-50yrs.
SITE: metaphysis is usually involved, it is common in phalanges
of hand and feet.
PATHOLOGY: tumor surrounded by fibrous capsule neoplastic
tissue is composed of bluish white translucent cartilage.
primitive mesenchymal cartilage is in periphery, while most
mature is in center of tumor.
q Signs and symptoms : incidentally diagnosed radio logically,
pain and enlargement of phalanx.
q X- ray : tumor appears cystic ( loculated or non ? loculated,
cortex- thin and expanded it may be perforated . No reactive
bone formation.
circumscribed focus of popcorn like densities is characterstic
of chondroma
Maffucci and ol iers syndrome ? associated with multiple
enchhondroma.
Treatment :
small ? curettage and bone grafting
recurrent ? radical resection
Osteochondroma (exostosis)
It is aberrant developmental anomalies formed of bone and
cartilage that arise from the periphery of cartilaginous growth
plate
Most common benign bone tumor
Incidence : 11%
Age : common during growth period
Sex : M : F :: 1.4 : 1
Pathology : usually lateral out growth of cartilage have all
histological feature of " epiphyseal plate" in their
cartilaginous cap . Grows until epiphysis fuses
Histology : deep layer of periosteum (cambium) retains ability
to form catilage and bone. Tumors may be due to perverted
activity of this layer
Signs and symptoms : symptom less, pain and swelling can
occur once bursitis or malignant changes occurs
firm to hard, fixed, painless mass overlying bone .
X- ray :flow out from cortex of metaphyseal area no reaction
of underlying bone .Cartilaginous cap and overlying bursa are
radiolucent
Malignant change occurs in 1-2%
Treatment :
? Observation
? Surgery- removal of tumor with resection of extracapsular
margins
CHONDROMYXOID FIBROMA
Least common benign cartilaginous bone tumor
Incidence : 0.4%
Age : 10-30 yrs
Site: upper end tibia ,lower end of femur , lower end fibula.
Pathology : collagen fibers abundant in this tumor. Cellular
population predominantly chondroid and myxoid in this case
C/F : mild pain ,swelling ,tender mass fixed to bone
X-ray : translucent mass of variable size located eccentrically
in the metaphysis , with in tumor faint trabecular pattern is
present .
Treatment : excision and bone grafting .
CHONDROBLASTOMA
Benign tumor arising in epiphysis consisting of
polygonal chondroblasts, small foci chondroid
tissue , osteoclast like giant cells and samll foci
of calcification .
Its importance lies in to differentiate from GCT
q INCIDENCE : 1 %
q Age : 10 -15 yrs
q Site :upper end humerus ,lower end femur, upper end tibia
q Clinical feature : pain ,swelling ,limitation of movememts
q X ray :lesion eccentric and involves less than one half of entire
epiphysis .
border of host bone sclerosis present, small puncture
calcification present
q treatment :currettage and bone grafting .
On MRI
GIANT CELL TUMOR
It is an osteolytic lesion arising from epiphysis common in
young adults .
Incidence : 5 %
Age : 20- 40 yrs (70 %cases )
Sites : epiphyseal region of long bones , pelvis and sacrum.
Pathology : soft tumor very friable readily bleeding tissue
contains cavitation and small cysts . Color of tumor varies
from reddish to chocolate brown .
Presence of abundant tumor giant cell and stromal
hyperplasia is characteristic .
C/F : chronic course , swelling , pain , pathological fracture .
egg cell crackling sensation is characteristic
X-ray : cortex is expanded and thin , osteolytic lesion ,no
periosteal new bone formation .
Thin septa of bone traverse the interior and produce " soap
bubble appearance"
q Treatment :
curettage and bone grafting ? recurrence is 40 %
Treatment -
Curettage and acrylic cementation
Curettage and bone grafting
Enblock excision for aggressive tumors
Benign Cystic lesions -
Unicameral bone cyst
Age : first 2 decades of life
Sex preponderance : M > F [2:1]
Location : long bones particularly metaphysis
Types of UBC
1. Active cystic lesion - within 1cm of physis
2. Benign latent cysts ? separated from epiphysis
Unicameral bone cyst (contd)
Pathophysiology
Unclear
Focal defect in metaphyseal remodeling
Recent studies show increased activity of lysosomal
enzymes in cyst fluid
Gerasimov AM et al(1991) Clin Orthop Relat Res.
Unicameral bone cyst (contd)
Pathology
Grossly, bone shows fusiform
expansion with thin cortex
On microscopy, lined by fibrous
membrane < 1mm thick,
composed of fibroblast,
mesenchymal cel s and lymphocytes
Histology of unicameral bone cyst
Unicameral bone cyst (contd)
Fig1: simple bone
cyst in proximal
humerus in 6 yr old
boy
Fig2: simple bone
cyst in proximal
femur in a 11 yr old
girl
Source: Greenspan 4th
ed ch 20
Simple bone cyst in proximal
humerus with fallen leaf sign
Source: Greenspan 4th ed ch 20
Treatment modalities
Percutaneous:
Steroid injections-methylprednisolone acetate (Scaglietti
et al 1974 Clin Orthop Relat Res.)
Other fibrosing agents
Trepenation (Komiya et al 1993 Clin Orthop)
Autologous bone marrow injection
Open procedure: sub-total resection with or without
bone grafting
Aneurysmal bone cyst
Age : usual y in 1st to 3rd decade of life .
Sex : slight female predominance.
Location : any bone may be involved.
Most common is proximal humerus
Types :
Primary : appears de novo following intraosseous A-
V fistula.
Secondary : results of cystic changes in GCT,
osteoblastoma
Aneurysmal bone cyst (contd)
Pathophysiology:
Unclear
Local circulatory disturbance leading
to increased venous pressure
Aneurysmal bone cyst (cont.)
Pathology:
? Grossly, cavitatory
lesion with blood
fil ed septate spaces
? On microscopy,
cavernous spaces
separated by
cel ular stroma ?
fibroblasts,
histiocytes, giant
Histologic appearance of aneurysmal
cel s
bone cyst
Source: Campbel 13th ed page 913
Gross appearance of ABC
Source: pathpedia.com
Radiograph of tibia showing
ABC
Source: Greenspan 4th ed ch
20
Aneurysmal bone cyst (contd.)
Other investigation:
Bone scan : shows dif use or peripheral tracer
uptake with decreased uptake in centre.
Ct scan : helpful in delineating the cyst
MRI : shows multi loculated cavities & fluid level
Aneurysmal bone cyst (cont.)
Treatment :
Curettage & bone grafting.
Marginal resection is indicated in expendable bone
Low dose radiation
Other adjuvants- high speed burr, cement, phenol,
argon beam coagulation, cryosurgery
Aneurysmal bone cyst (contd)
Alternative treatment:
Arterial embolization
Sclerotherapy
Curopsy (Reddy et al Clin Orthop Relat Resp 2014)
Percutaneous doxycycline (Fife et al J Lab clin Med 1997)
Denosumab
Bisphosphonates
Case 1:
12 year old female presented with pain and swelling left knee for 3 months.
Diagnosed as ABC and treated with curettage and bone cement.
Case2:
40 year old male presented with complain of pain
knee and swelling. First diagnosed as ABC treated
with intra-lesional sclerosant.
FIBROUS DYSPLASIA
Intrinsic defect of endo-chondral bone maturation results
in incomplete or immature ossification , the absorbed
bone is replaced by fibrous osseous tissue.
Incidence : 0.8%
Age : 3-15 yrs .
Site : diaphysis or metaphysis of femur , tibia , fibula.
Pathology : appearance of immature bone in a sea of fibrous
connective tissue.
immature dysplastic trabeculae are round, plump .
Multinucleated giant cells +
q Clinical features : in wt. bearing bones marked deformity ,
pathological # +
" sheperd crook " deformity of proximal femur is commonest
deformity ( 1-30 cms size ).
Albright syndrome ? precocious puberty , fibrous dysplasia,
brown skin patches.
X ray : cyst like lesion in diaphysis or metaphysis with
endosteal scalloping with or without bone expansion.
Uniform distribution of dysplastic trabeculae gives ground
glass appearance.
q Treatment: Aim is to supplement dysplastic bone with bone
cement and mechanical support by implants to produce
strength to prevent deformity and fracture than to eradicate
disease.
Ground glass appearance
Shepherd crook deformity
Conclusion
Benign cystic lesions can mimic aggressive and malignant lesions of bone
and vice versa
Despite multi-modal approach to diagnosis of bone lesions, HPE remains
the standard method
Standard treatment of benign cystic remains curettage/resection with
bone graft despite advent of new treatment .
Thankyou
MCQ 1
Fallen leaf sign is a feature of
1. Giant cell tumor
2. Unicameral bone cyst
3. Fibrous dysplasia
4. enchondroma
MCQ 2
Egg crackling feature is diagnostic of
1. Giant cell tumor
2. Enchondroma
3. Fibrous dysplasia
4. Unicameral bone cyst
MCQ 3
A 25 years old female presents to us with a swelling
around knee. On histopathology there is abundance of
giant cell in the backdrop of mononuclear cells. What is
the most probable diagnosis
1. Fibrous dysplasia
2. Giant cell tumor
3. Aneurysmal bone cyst
4. Unicameral bone cyst
MCQ 4
Treatment of shown exostosis with no sign of deformity,
neural or vascular compression and ceased growth is
1. Excision of tumor
2. Observation
3. Radical excision
4. Radiotherapy + chemotherapy
MCQ 5
A well demarcated bone forming tumor with well
defined nidus on CT scan is diagnostic of
1. Osteoblastoma
2. Osteoid osteoma
3. Chondroblastoma
4. enchondroma
This post was last modified on 07 April 2022