Bone tumors

Tamara shawabkehKhozama khalafat

Heba Rbab3h

Outlines

• •Introduction (signs, symptoms, investigation)

• •Benign tumor

• •Malignant tumor

• •Metastatic bone tumor

Bone tumors

• Rare tumors (< 2%)

• More in young ages

Begnin vs malignant tumors

•Rapid growth

•Warmth

•Tenderness

•Ill-defined edges

All are suggestive of malignancy

• Classification

• Origin:

• –Primary

• –Secondary (95%): breast, lung, prostate, kidney and thyroid

• cell type:

• –Bone: Osteoma, osteosarcoma

• –Cartilage: Chondroma, Chondrosarcoma

• –Marrow: Hemangioma, angiosarcoma

• –Fibrous tissue: Fibroma, fibrosarcoma

• Tumor type:

• –Benign: Osteoma, osteochondroma

• –Malignant: Osteosarcoma, chondrosarcoma

Investigations

• History and examination

• Imaging (x-ray, CT, MRI & bone scanning)

• Biopsy

• Labs

• Ca & P: Greater than normal levels may indicate bone metastasis.

• PTH: Lower than normal levels may indicate bone metastasis.

• ALP isoenzyme: Higher than normal ALP levels may indicate Paget's disease, osteoblastic bone cancers, osteomalacia and rickets.

• LDH: High values indicate poor prognosis

Plain X-Ray

•Most useful

•Could see:

•Lump

•Cysts

•Bone destruction

•Cortical thickening & periosteal reaction

•Important to notice:

Where,How many, Cystic or not, Margins, Destruction

Periosteal reaction•Periosteal hypertrophy which develops in response to periosteal irritation. They are a non-specific sign.

•They have many causes:

-Infections

-Tumors (both benign & malignant)

-Benign tumors are thick & smooth or completely absent

-Malignant tumors are thinner & irregular (wavy).

-Healing fractures

-Chronic stress

• Periosteal reactions seen in the distal tibia and fibula.

• Periosteal reaction at the distal radius with irregular edges: malignant.

Midshaft periosteal reactionwith smooth + thick edges: this is a benign osteoma.

•CT and MRI

•Asses the extent of the tumor

•Relation to surrounding structures

•bone scan:

•Helpful in revealing site of a small tumor

•Skip lesions

•Silent secondary deposits

• Multiple hot spots seen: lung cancer which has metastasized to vertebrae.

Biopsy•Allows us to reach a diagnosis.

•Allows us to plan for treatment.

Methods:

•Open biopsy: surgical procedure done under GA.

•Zonal biopsy: open biopsy from transition zone.

•Excisional biopsy: excision of the entire tumor.

•Large–bore needle biopsy: aspirating cells.

Complications:

•Hemorrhage

•Wound break down

•Infection

•Pathological fractures

Benign tumor Bone Forming Tumors1-Osteoid osteoma2-Osteoblastoma Fibrous Tumors 1- Histiocytic Fibroma (old name NOF; Non-ossifying fibroma) 2- Fibrous DysplasiaCartilage-Forming Tumors 1- Enchondroma2- OsteochondromaCystic and Vascular tumors1- Simple Bone Cyst

2- Aneurysmal Bone Cyst Giant Cell Tumor (Osteoclastoma)

Begnin bone tumors

Osteoid osteoma○ Shaft of tibia and femur

○ Present with night pain that responds to NSAIDS.

○ < 2 cm

○ DDx: Brodie’s abscess “subacute osteomyelitis” but not cortical → >2 cm Night pain relieved by NSAID is seen in Osteoid osteoma and Brodie’s abscess.

○ May Resolves spontaneously in 3 years in certain cases but because it's painful patient does not wait for 3 year!!

○ Nidus can be removed surgically or now radiofrequency ablation

○ No malignant transformation

• Plain radiograph in a 25-year-old male with cortical osteoid osteoma. shows a radiolucent nidus surrounded by fusiform cortical thickening

• Nidus: tiny radiolucent area.

• Diaphysis surrounded by dense bone and thickend cortex.

• Metaphysis less cortical thickening.

Transaxial CT scan through the proximal shaft of the right femur in a 17-year-old boy, Osteoid osteoma.

bone scan shows focal intense activity at tumor site.

Osteoblastoma

Osteoblastoma (big brotherof osteoid osteoma)

○ Usually in the spine (spinous process)

○ Presents with pain that doesn’t respond to NSAIDS (pain not necessarily at night)

○ > 2 cm

○ Removed surgically

○ Histopathologically similar to osteoid osteoma.

Begnin Fibrous Tumors

Histiocytic Fibroma

● Histiocytic Fibroma (old name NOF; Non-ossifying fibroma)

○ Most common benign lesion of the bone

○ Failure of ossification of certain parts of bone → fibrosis.

○ Asymptomatic and is always encountered in children, Usually an incidental finding.

○ Can present with pathological fractures esp. if large.

○ NOF is a misnomer as there might be ossification

○ Considered a defect not a tumor

○ Usually in the metaphysis of long bones

○ Takes a long time to heal spontaneously up to 30 years (the lytic part decreases and the surrounding part ossifies)

•Well marginated radiolucent lesion

•Distinct multilocular appearance

Fibrous Dysplasia○ Is a tumor due to Gs-protein mutation.

○ 1% malignant transformation

○ Trabecular bone “spongy bone” becomes fibrous tissue with woven bone giving rise to the ground glass appearance due to normal body reaction to fibrous tissue

○ Most common site is proximal femur then ribs then tibia

○ Monostotic “single bone” → 80%, polyostotic “several bones” → 20%

○ Associated with McCune-Albright syndrome (endocrine abnormalities such as precocious puberty and also has café au lait spots with irregular margins unlike NF) McCune-Albright syndrome is associated with the polyostotic type but rarely can be with monostotic

○ There might be a Shepherd's crook deformity لراعي ةا coxa varus angulation”عصاof the proximal femur” due to weak bone bearing weight which might appear on x-ray

Treatment:

○ If small → observe

○ If large → curettage and grafting (cortical allograft to prevent recurrence if it was autograft)

○ Bisphosphonates only improve the symptoms by inhibiting the osteoclasts

cartilage-forming tumors

Osteochondroma

• Osteochondroma M.C benign bone tumor (Histiocytic Fibroma → Most common benign lesion of the bone)

• t is a developmental lesion which starts as a small overgrowth of cartilage at the edge of the physeal plate

• It grows with the pt until 16-18 years, if it grows after 18 years → malignant transformation

• It looks (on x-ray) smaller than it feels because the cartilage cap does not show on X-ray.

• The exostosis may go on enlarging up to the end of the normal growth period for that bone. Any enlargement after that is suggestive of malignant change → chondrosarcoma

• Indication for Treatment: surgery if it was long and cause mechanical block or fracture or for cosmetic reasons.

Cystic tumors

Simple bone cyst

Simple Bone Cyst

○ a true solitary bone cyst. (Like a balloon in the bone) → purely lytic

○ appears during childhood, typically in the metaphysis of one of the long bones and most commonly in the proximal humerus or femur.

○ heals spontaneously and is seldom seen in adults.

○ usually discovered after a pathological fracture or as an incidental finding on X-ray.

○ Treatment:

■ Asymptomatic lesions→ no tx , but the patient should be cautioned to avoid injury which might cause a fracture.

■ Active cysts (those in young children, usually bordering against the physeal plate and obviously enlarging in sequential X-ray should be treated, in the first instance, by aspiration of fluid and injection of 80-160 mg of methylprednisolone. This has been found to stop further enlargement and promote healing of the cyst.

■ If the cyst goes on enlarging, or there is a pathological fracture, the cavity should be curetted and then packed with bone graft → treat as a fracture

A 9-year-old girl with a simple bone cyst in the distal diametaphyseal

region of the tibia. Lateral radiograph reveals the simple bone cyst

complicated by a pathologic fracture.

DDx

○ Chronic osteomyelitis

○ Stress fractures: X-rays show an area of cortical “destruction” and overlying periosteal new bone; if a biopsy is performed, the healing callus may show histological features resembling those of osteosarcoma (Looks like immature bone formation)

• Principles of treatment

○ Benign + asymptomatic

■ If the diagnosis is beyond doubt, treatment may never be needed. Otherwise a biopsy is advised ○ Benign + symptomatic

○ Benign + symptomatic

■ Always require a biopsy to confirm the diagnosis, generally removed by complete local excision