DEPARTMENT OF ORTHOPAEDICS

GANDHI HOSPITAL

BENIGN BONE TUMORS - Dr P.Nagendra Post graduate( M.S

Ortho)

cartilage lesions :

- osteochondroma

- chondroma

enchondroma

periosteal chondroma

• OSTEOCHONDROMA -also called osteocartilagenous exostosis

- mc skeletal neoplasam - developmental anamoly

- Cartilage capped subperiosteal bone projection

< 20 yrs age

site : long bones esp. distal femur & proximal tibia

also ilium ( crestal border ) , scapula (vertebral border ) , ends of clavicle , calcaneum .

Clinical features :

- usually symptomless

- painless lump

- pain due to pr on surrounding structures

or # or bursitis

- pseudoaneurysm of large v. noted

- grows till skeletal maturity

- spon. Resolution well documented

Radiographic features - Pedunculated or sessile

- sessile lesions – metaphyseal widening ( trumpet shaped deformity )

- metaphysis

- cortex & cancellous bone of the lesion blend with the parent bone – CT is more helpful

- Directed away from growing end of bone

- Irregular calcification with areas of uncalcified cartilagenous islands – radiopaque areas

- U.S – for thickness of cartilage cap

pathology :

endochondral ossification of hyaline cartilage – like a normal growth plate but more disorganised

DD :. juxtacortical chondroma ( cortical defect )

. myositis ossificans ( don’t blend with parent bone)

. parosteal OS ( ill defined margins )

- Sarcomatous change < 1 %

more distal – less chance

In pelvis , scapula , vertebra – 10 %

Treatment - asymptomatic – no Rx

- excision – if symptomatic

en bloc resection with a rim of normal bone surrounding its base and the entire overlying bursae

excision if possible postponed until later adolescence

Hereditary multiple exostosis - autosomal dominant

- < 10 yrs

Clinical features :

- knobby appearance

- short stature or even dwarfed ( limbs short in relation to trunk )

- Deformity of forearm - in 40 – 60 %

ulna short , radius bowed , loss of pronation n supination , tibiofibular synostosis , genu valgum , coxa valga

DD : multiple enchondromatosis , achondroplasia

Treatment : excision of symptomatic exostosis

correction of deformity & limb length discrepancy

ENCHONDROMA - solitary, benign ,intramedullary tumor - Mc primary tumor in hand - 3 to 4 th decade - Site : short tubular bones of hand & feet

hand > feet

proximity to epiphyseal plate - Clinical features : asymptomatic

swelling or pathological #

pain without # suspect malignancy

- Caused by failure of normal endochondral ossification

- Radiographic features :

well circumscribed , distinct rarefaction , expands the bone , intralesional calcification -“spotty or punctate”

DD : epithelial inclusion cyst,

SBC & NOF

Olliers ds : multiple enchondromatosis

with hemangiomas : maffucci s syndrome

Favouring malignancy - Pain without # - Rapid increase in growth - More proximal lesions - Multiple enchondromatosis - Bone scan activity greater than that of ASIS on

comparison

TREATMENT : symptomatic – curettage & graft

if # has occurred – delayed until # heals

PERIOSTEAL CHONDROMA -also called juxtacortical chondroma

-uncommon tumor < 100 cases reported

Site : proximal metaphysis of humerus - Painless swelling - Continues to grow even after skeletal maturity - Radiological : radiolucent lesion

on surface of bone ,

rim of osteosclerosis ,

no penetration into medullary canal ,

Saucer like erosion

DD : fibrous cortical defect ,

soft tissue tumor sec involving cortex

periosteal chondrosarcoma

periosteal osteosarcoma

TREATMENT :

diagnosis sure & asymptomatic – observation

Otherwise – en bloc excision & grafting

curettage – high chance of recurrence

CHONDROBLASTOMA-also called codmans tumor - Rare - Arising from the immature cells of epiphyseal

cartilage - 10 to 20 yrs age - M > F- Site : upper humerus , upper tibia , lower femur - C .F : pain without h/o trauma

synovitis

rare development of pulmonary mets in histologocally benign chondroblastoma is well documented

Radiographic features :

age ,

epiphysis

lytic

well defined margins

fine calcification – punctate or in rings may be seen

DD : GCT

TB

ABC

Central chondrosarcoma

eosinophilic granuloma

Treatment : curettage

excision if location permits

CHONDRMYXOID FIBROMA

- extremely rare - 2nd to 3rd decade - Site : metaphysis of proximal tibia - Presents with mild pain or swelling - Radiographic findings : eccentric

lytic, well defined margins , metaphysis , oval with axis parallel to diaphysis ,

as lesion progresses – bite like cortical destruction ,

no periosteal reaction, no mineralization of matrix

DD : fibrous cortical defect ,

ABC

Fibrous dysplasia

UBC

Pathology : very close to chondrosarcoma . Radiology helps to make the final diagnosis.

Treatment : curettage or

excision

Fibrous lesions : Nonossifying fibroma Cortical desmoidBenign fibrous histiocytoma Fibrous dysplasia Osteofibrous dysplasia

NON-OSSIFYING FIBROMA - Also called fibrous cortical defect or metaphyseal

cortical defect - Mc musculoskeletal tumor - Occurs in 30 % of children - 1st two decades - Site : femur , tibia , humerus ( 8 % - multiple

lesions) - Asymptomatic - X ray : well defined , eccentric , radiolucent

lesion , rim of sclerosis , doesn’t expand the cortex & no periosteal reaction.

- Treatment : observation

CORTICAL DESMOID - Irregularity in posteromedial aspect of distal

femoral metaphysis - In boys , 10 – 15 yrs age - Reaction to muscle stress – Add. magnus - Best seen on oblique radiograph – lower limb ext.

rotated 20 – 45⁰- On x ray – erosion of cortex with sclerotic base - No treatment needed

BENIGN FIBROUS HISTIOCYTOMA - Also called fibroxanthoma / primary xanthoma of

bone- Rare - Site : diaphysis or epiphysis of long bones

pelvis ( ilium – mc site )

rib , clavicle , spine

C.F : local pain , swelling or #

Radiographic findings : lytic , sharp margins , sclerotic rim , expansion of affected bone , no matrix mineralizsation ,

Larger lesions destroy cortex

Treatment : curettage & grafting

FIBROUS DYSPLASIA -intrinsic defect of endochondral bone maturation

immature ossification pattern

-Characterized by benign fibrous stroma , stipled with bony islands of metaplastic bone weakbone .

- Solitary or multifocal - ALBRIGHT ‘ S SYN : polyostotic F.D + cafeaulait

spots + endocrinopathies .- Site : rib , femur , humerus , tibia , maxilla - C.F : monostotic – asymptomatic

bone pain , skeletal deformities .

Radiographic features : - Epiphysis or metaphysis or diaphysis - Well defined geographic lytic lesions - Ground glass matrix : intramedullary

radiolucencies- Cortical thinning - Secondary deformities esp. in wt , bearing bones

- shepherd’s crook deformity

( microfractures – on tension side of bone ) - Poorly defined areas of osteolysis suspect - Cortical destruction malignant - Soft tissue involvement

transformation

- Treatment :

monostotis lesions asymp no Rx

Indications : severe deformity

persistent pain

pathological # - Curettage & grafting ( cortical allograft

prfrd.)- Internal fixation +/- osteotomy - Bisphosphonates : beneficial

OSTEOFIBROUS DYSPLASIA- Also called campanacci disease - Rare affecting tibia & fibula

- 1st two decades - Middle third of tibia – mc site - Pain usually absent , bowing of tibia or pathological

# - Xrays – eccentric intracortical osteolysis with

expansion of cortex- DD : adamantinoma & monostotic f.d - Don’t progress after puberty - Rx : pathological # - conservative - Deformity – surgical correction

bone forming tumors :

osteoid osteoma

osteoblastoma

bone island

OSTEOID OSTEOMA - Osteoblastic mass called nidus surrounded

by zone of reactive sclerosis - 2nd decade - M > F- Site : proximal femur ( mc ) , tibia ,

spine ( posterior elements )

not seen in bones of membranous origin

C. F : dull pain , worse at night , relieved with NSAID s , not related to position or function , often aggravated by alcohol

- Pain is elicited by local pr. - O.O is suspected in spine when a pt < 30 yrs

complains of constant back pain , when spine is stiff and scoliotic & SLRT is positive with no signs of nerve root compression.

Radiological findings : radiolucent nidus with reactive sclerosis in cortex ,

DD : osteoblastoma ,

non-suppurative osteomyelitis of garre ,

brodies abscess, stress # ,

Diagnosis : bone scan – “headlight in fog “ & “double – density sign “

CT – BULLS EYE appearance

Pathology :

nidus – osteoblasts & nonmyelinated axons

Stroma – osteoblasts , osteoclasts , fibroblasts & blood filled capillaries

- Transform into osteoblastoma but no malignant transformation.

Treatment : self limiting lesions – conservative treatment with NSAIDs – not well tolerated

- Surgery : to eradicate pain producing nidus ( accurate localization is hence crucial )

methods : - en bloc resection or burr down tech.

latest is percutaneous radiofrequency ablation

OSTEOBLASTOMA

- Histologically similar to O.O but differing in progressive growth & absence of reactive perifocal bone formation.

- Potentially malignant - Mc site : vertebral column ( post. Elements)- C.F : pain of varying intensity

pathological #

neurological problems

Radiographic features : nothing particularly distinctive

well circumscribed lesion ,

On CT – COTTON WOOL appearance due to irregular opacities

- Radiopacity expression of quqntity & degree of maturation of osteoid substance.

Bone scan – localizing smaller lesions esp in spine

Pathology : very vascular

DD : osteoid osteoma osteosarcoma ( increase in sr. ALP).

Treatment : curettage & bone grafting

BONE ISLAND - Also called enostosis - Benign lesions of cancellous bone - Ostepoikilosis – multiple bone islands throughout

the skeleton - Majority – asymptomatic - On radiographs – small round / oval homogenous

areas of increased density

brush like border

no bony destruction / periosteal reaction

- Treatment : observation & follow up

if pain or lesion grows – biopsy to r/o sclerosing osteosarcoma, blastic metastasis, or sclerotic myeloma.

Cystic lesions : Unicameral bone cyst Aneurysmal bone cystIntraosseous ganglion cyst

UNICAMERAL BONE CYST - Developmental anamoly of physis - Transient failure of ossification of physeal

cartilage & cyst formation- < 20 yrs age , M > F - Spontaneously resolve in late adolescence , rarely

persist into adulthood - Site : proximal humerus ,

proximal femur , calcaneum .

Active cysts are juxtaposed to physis

C.F : usually asymptomatic ,

pathological #

-cysts progress from active to quiescent to involutional stage . - cysts usually shrink as patient approaches skeletal maturity.

- Radiographic features : metaphysis of immature skeleton ,

well marginated ,

centrally located ,

radiolucent that expand and thin the cortex .

FALLEN FRAGMENT SIGN - # fragment in the cyst

DD : ABC & fibrous dysplasia

Treatment :

small asymp lesions in upper extremities – observation & follow up

Larger lesions

Symptomatic lesions need Rx

Lesions in lower extremities

- various options are

curettage +/ - bone grafting +/- int. fixation

aspiration & inj of steroids or bone products

FALLEN

FRAGMENT SIGN

ANEURYSMAL BONE CYST - Expansile , blood filled , intramedullary lesion - Young adults - Metaphysis of long bones or vertebrae - Radiographic features : eccentric

radiolucent , thinning of cortex ,

honey-comb internal architecture

well defined margins ( poorly in spine )

Treatment : excision – cortical based or surface tumors

extended intralesional curettage & grafting – central lesions

Embolisation – vertebral & pelvic ABC

Low dose radiation – effective method

INTRAOSSEOUS GANGLION CYST - In middle aged men - Ends of long bones – distal tibia , shoulder

- intraosseous extensions of ganglia of local soft tissues

- On radiographs & MRI: uniloculated or multiloculated, well-demarcated, lytic defects with a thin rim of sclerotic bone

- Treatment – if symptomatic

curettage & excision of overlying soft tissue

NON – NEOPLASTIC LESIONS

BROWN TUMOR OF HYPERPARATHYROIDISM

-in hyperparathyroidism skeletal change is diffuse dimineralization

rarely – markedly focal – BROWN TUMOR

DD : G.C.T

diagnosis : Sr . Calcium , phosphorous , ALP & PTH

BONE INFARCT- In pts with steroid use , alcoholism , sickle cell

anaemia , dysbaric conditions . - X rays : well defined , metaphyseal , irregular

margins

periphery – calcified ( chondroid lesions – calcified throughout )

- Asymptomatic – if pain – other etiology - M.F.H can occur at site of bone infarct

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