Dr. Sidharth yadav Orthopaedic dept.

Diagnosis of cystic lesions in skeletal system is based on radiologic analysis.

Radiologic analysis of bone lesion that are lytic 7 question has to be asked :-

Where is the lesion? How large is the lesion ? What’s the lesion doing to bone ? What is bone doing in response ? What kind of matrix ? Is the cortex eroded or intact ? Is there any soft tissue extension ?

Solitary bone cyst Aneurysmal bone

cyst Fibrous dysplasia Chondroma Chondromyxoid

fibroma chondroblastoma

Brown tumour hyperparathyroidism

Hydatid cyst Intraosseous

Ganglion Epidermoid cyst Giant cell tumour Fibrous cortical

defect

Is a common lesion of unknown cause & pathologyAge :- most commonly in 5-15 yrs rarely after 20 yrsSex :- male predominant (2:1)Location :- long tubular bones particularly

humreus & femur -metaphysael region is the preferred site.

2 types :-

Active cystic lesion :- develops under 10yrs age -adjacent to the epiphyseal plate.

Benign latent cyst :- develops after 20 yrs age

- seprated from epiphysis

Physical findings :- - Usually asymptomatic.-Cyst lying adjacent to growth plate can lead to growth disturbances.

X ray findings :- centrally located,lytic lesion.-Expansion of the bone.-Well marginated outline.-Thinning of the cortex( scalloping).- Fallen fragment sign- Periosteal surface is smooth.-loculated appearance is due to presence of ridges over inner surface of cyst.

Pathology :- Gross :- - Bone displays an area of fusiform expansion.- Underlying bone is egg-shell thin.- Cavity contain yellow fluid.- Thin layer of connective tissue lines the cavity that gives the pseudoloculated apperance on x-rays.

Microscopic :- - Connective tissue composed of fibroblast contaning multinucleated giant cells , foam cell.- Cortical wall consist of lossely trabeculated osseous tissue & many thin walled vessels.

Diagnosis :- -Is establisehed by aspiration , injection of radio-opaque substance & direct operative exposure.

Treatment :-Curettage Aspiration Steroid injection

Solitary expansile Blood filled reactive lesion of bone .Locally destructive.Age :- usually in 1st ,2nd & 3rd decade of life .

Sex :- slight female predominance.

Location :- any bone may be involved. -Most common is proximal humreus ,distal femur,proximal tibia & spine.

Types :-

Primary :- apperas de novo following intraosseous A-V fistula.Secondary :- results of cystic changes in GCT ,OSTEOBLASTOMA etc.

Clinical feature :--Pt complain of mild to moderate pain.-Swelling -Limitation of joint movements.-Neurological deficit or radicular pain.-Rapid growth may occur which clinically presents as a malignancy.

X ray findings :-Affected bone is expanded, cystic & ballooned outward.Ecentricaly placed.Cortex is breached.Surrounded by a faint outline representing new periosteal bone.

PATHOLOGY :-

GROSS :--Large mass is attached by a broad base to the shaft of long bone .-Growing outwards & displacing the soft tissue.-Thin shell of bone enclosing the blood filled spaces.-Bony shell is easily penetrable with a liver like friable mass interposed with gritty bone particles is encountered.

Microscopic :--Bone & marrow are replaced by the large pool of blood enclosed in fibro osseous septae.-Connective tissue bordering the vascular space contain multinucleated giant cells, new bone formation & calcium deposits.

Other investigation:-Bone scan :- shows diffuse or peripheral tracer uptake with decreased uptake in center.

Ct scan :- helpful in delineating the cyst in complex area ex. Spine ,pelvis .

MRI :- shows multi loculated cavities & fluid level.

Treatment :--Currettage & bone grafting.-Marginal resction Is indicated in expendable bone-Low dose radiation has been used effectively ,associated with rapid ossification.

•Benign lesions of hyaline cartilage.

•It can arise with in a bone ( ENCHONDROMA)

or on the surface of abone ( PERIOSTEAL /JUXTACORTICAL CHONDROMA).

•Usually presents as a solitary lesion but multiple lesion can also be present (enchondromatosis/OLLIER’S disease).

•Tumour may be accompanied by a vascular lesion (MAFFUCCI’S SYND.)

Age :- usually all age group are affected .More commonly young individiual in 2nd -4th decade.

Sex :- equally (M:F=1:1)

Location:- any bone can be affected but commonly phalanges of hand & feet.-solitary enchondromas involve humreus , tibia & femur.

Clinical findings :-

-Swelling-Tenderness -Pain

Pathology :- Gross :--Tumour is surrounded by a fibrous capsule.-The neoplastic tissue is composed of bluish white translucent cartilage- Areas of calcification.

Microscopically :--Tumour shows stages of cartilage formation.-Mesenchymal tissue is seen at periphery.-Most mature cartilage is seen at center.

X RAYS FINDINGS :-

-small loculated area with well defined margins.-Cortex is thinned & expanded.-Interlesional calcification :- calcification is irregular Stippled ,punctate or popcorn.-no reactive bone formation

CT scan :- Evaluate endosteal erosion to rule out chondrosarcoma.

Treatment of solitary enchondroma consisit of oberservation with serial radiographs.

If the lesion apperas to be radiographically stable & asymptomatic then no further investigation is required.

If the lesion appers to be unstable , growing then extended curettage is done.

-Least common cartilage tumour.

-Not known to metastasize.

-2% of all benign tumour.

-Seen in patients <30yrs specially in 2nd

& 3rd decade

-Tumour is more common in male (M:F=2:1).

-Observed in long tubular bones specially in lower extermity.

Clinical features:--Pain near the joint without h/o trauma-Occasionally swelling-Pathological fractures ( rare)-May presents with soft tissue swelling.

Radiographic findings :--Translucent mass located eccentrically.-Fusiform expansion in small bones.-Cortex is expanded & thinned.-Margin’s are scalloped & sclerosis +.-Periosteal reaction is uncommon.

Pathology :-Gross :--Cut surface reveals solid tumour mass containing small cavities with mucoid tissue.-Calcified areas are unusual.-Surface is sharply demarcated ,lobulated & surrounded by thin scalloped border of dense bone.

Microscopic :--Composed of lobulated areas of stellate cells with indistinct cytoplasmic borders.-At the periphery ,the appearance is more cellular & collagenous.

-local excision & filling the cavity with autogenous bone.

-Curettage is not sufficient as tumour may recure especially childrens.

-Wide en- bloc excision gives high rate of cure.

-If tumour recure even after en bloc excision then studies has to be done to rule out the malignant transformation.

-Non inherited, sporadic developmental anomaly.-Replacement of bony tissue with fibrous tissue.Age :- begins in childhood(<10 yrs).Sex :- M:F=1:1Location :- base of the skull & long bones.

Clinical features:--Pain -Limp-Deformity-Asymmetry of face-Endocrine disorder- Limb length discrepancy.

Pathology :-

Gross :--Bone is irregular in shape & bent.-Grey tough fibrous tissue that cut with a gritty resistance “SANDPAPER”

Micro :- -composed of dense,mature collagenous tissue.-fibroblast are oriented in linear /whorl pattern.

Radiological findings :--intramedullay & predominantly diaphyseal.-central or ecentric in location.-Ground glass appearance.-lesion is well defined with sclerotic margins-Cortex thinning & expansion is seen.-Pathological fractures .-Bowing of bones.-HARRISON’S GROOVE.

- Conservative management includes bracing & modification of activities.

Surgical management :--Pathological fracture usually heals but develops deformity.

-Fracture of long bone should be treated preferably with I.M nails along with bone grafts.

Large lesion which jeopardize the integrity of bone should be treated with currettage & bone grafting

-Benign well circumscribed fibrous growth with in a small area of long bone.-A/k/a nonossifying fibroma,fibroxanthoma-Localised form of fibrous dysplasia.

Age :- <30yrsLocation :- metaphysis of long bone.

-usually lower limb.Sex :-M:F=1:1

Clinical feature :- -usually asymptomatic -occasionally presents with pathological fracture.

Pathology :-Gross :- thin cortex enclose soft /tough rubbery gray –yellow or reddish brown tissue.

Microscopic :-Spindle shaped cell distributed in a whorled pattern.Fibroblastic proliferation with high cellularity.Giant & foam cells are present.

X ray findings :--well defined lobulated lesion.-Ecentrically placed.-Cortex thinning & expansion -Multilocular appearance or ridges in bony wall.-No periosteal reaction.

Treatment :-Excision & curettage

-Hyperparathyroidism results in disorder of bone & mineral metabolism.-Diffuse & focal lesion may arise in multiple bones.-These lesion are K/as brown tumours due to the presence of haemorrhage in the lesion.

Location :- Any bone can be affected.Mainly diaphysis of long bone.

Clinical features :- StonesBones Groans

Radiological features :-Salt & pepper skullMultiple osteolytic lesions

Laboratory findings :-↑ed levels of PTHHyper calcemia↑ed serum phosphate & urate.

TREATMENT :- treatment of the primary cause will cause the healing of lesion.

-Lesion of uncertain pathogenesis.Age :- can occur at any age.-Most commonly seen in 20-60yrs age .

Location :- subchondral region of tubular bone ,acetabulam & carpel bones.-Simultaneous occurrence of peri osseous ganglion cyst .-This led to the theory of adjacent soft tissue ganglion extension in bone.

Clinical feature :-are usually clinically silent.-Chronic pain -Swelling if associated with soft tissue ganglion.-Usually solitary

Radiogaphic findings :--Well demarcated ,sharply circumscribed osteolytic lesion.-Sclerotic margin is evident.-In para articular location gas may be evident.

Treatment :-- Local excision of overlying soft tissue & curettage of involved bone.- Recurrence is rare.

-Uncommon.-Due to the intraosseous implantation of epidermoid tissue .-M >FAge :- usually in 2nd ,3rd & 4th decade of life.Location :- skull & phalanges of hand are commonly affected.

Clinically :--Pain & swelling

Microscopically :--They resemble epidermal cyst of skin.

-Cysts are filled with keratinous material & lined by squamous epithelium.

RADIOGRAPHIC :-Well defined osteolytic lesion with sclerotic margins .

CT & MRI are rarely required.

Treatment :- Excision