Malignant bone tumors

Osteosarcoma Pathology:• Also called osteogenic sarcoma.

• It’s a primary malignant bone tumor produces osteoid tissue.

• It destroys bone and spread into the surrounding tissues and along the medullay canal.

• At the same time it forms abnormal new osteoid in some of its parts, so it destroy bone at the same time it forms new abnormal bone tissue.

• It’s easily metastatized via blood and reaches such organs like lung, liver, other bones, …etc.

Clinical features:

• It’s seen at the age of 10-20.

• It’s a metaphysical lesion usually seen around the knee and in proximal humerus.

• 50% present with history of trauma.

• Pain is a major symptom its usually severe constant and mainly at night.

• Sometimes lump is the presenting symptom.

• O/E, swollen tender lump without defined margins.

• Overlying skin is thin, shiny and warm.

• ESR is high.

Imaging

• X-ray shows changes of bone destruction and new bone formation in the metaphysis (rarefaction + sclerosis).

• Cortical perforation and soft tissue swelling.

• Subperiosteal new bone formation sometimes in the form of Codmen’s triangle and/or sun burst appearance.

• CTscan, MRI, and bone scan can show the tumor extent and possible local and distant metastasis.

• Pulmonary CTscan can show possible lung metastasis.

Incisional biopsy is essential to

establish diagnosis

Treatment of osteosarcoma:

• The use of cytotoxic drugs is useful, it increased the 5-year survival of patients up to 50% or even more.(10 years survival)

• Eradication of the primary tumor is essential by radical amputation.

• Pre and postoperative cytotoxic drugs are essential especially if there is metastasis, it should go for at least one year.

• Irresectable tumors can be treated with combined chemo and radiotherapy.

Chondrosarcoma

Its of two types; primary and secondary.

• Primary type:• Its slowly growing form occurs in the flat

bones mainly or in the medulla, sometimes mistaken for chondroma.

• Rarely seen before the age of forty.• Presents with pain and possible

pathological fracture.• X-ray shows destructive medullary tumor

with possible flecks of calcification

• Secondary type:

• Arises as malignant transformation of a primary chondroma or osteochondroma.

• A previously benign tumor and after stop of bone growth starts to increase in size and gets painful.

• Sometimes it reaches very large size before being discovered especially in the scapula or pelvis where there is big space for tumor growth.

• X-ray shows the original lesion being enlarged and covered with fluffy flecks of irregular calcifications.

• Before treatment we investigate the patient with CTscan, MRI and bone scan to establish the diagnosis and see the extent of tumor and its metastasis.

• Biopsy is always essential to establish diagnosis.

The tumor metastasis is late, because of that surgical treatment is always useful with wide local excision or amputation.

Sometimes we use radiotherapy for irresctable tumors.

Fibrosarcoma

• It’s a rare bone tumor.

• Usually arises from a previous abnormal lesion like fibrous dysplasia, bone infarct or after irradiation.

• Patient usually an adult have pain and swelling rarely pathological fracture.

• X-ray may show localized bone destruction, MRI, CTscan can show local extension.

• Low-grade tumors can be treated with wide excision and prosthesis.

• High-grade tumors needs radical resection or amputation.

• Radiotherapy may be useful.

Ewing’s tumor

• Malignant tumor of vascular endothelium of bone marrow ???

• Occur at the diaphysis of long bones commonly tibia, fibula and clavicle.

• It causes severe type of periosteal new bone formation.

• It’s readily metastasize through blood (sometimes its regarded as blood disease).

• Usual age is 10-20.

• Pain and swelling is the common presenting features, sometimes there is fever and local lymph node enlargement.

• There is tender ill-defined mass which is warm.

• Differential diagnosis is acute osteomylitis

• X-ray shows diaphysial lesion with bone destruction and multiple layers of periosteal new bone formation in an Onion-Skin appearance.

• Bone scan shows increased activity.

• Biopsy is highly indicated.

• Treatment includes all methods of radical surgery, chemotherapy and radiotherapy.

Multiple myeloma

• It’s a tumor of plasma cells of red marrow wherever it’s found, mainly long bones, pelvis and spine.

• Usually its multiple but rarely its localized solitary myeloma lesion and called plasmacytoma.

Clinical features:

• Patient aged 45-65, presents with pain or pathological fracture.

• Pain is constant, severe mainly backache and possible root pain.

• Anemia, cehexia and chronic nephritis with general ill health all may present.

• ESR always very high.

• Main cause of death is renal failure.

X-ray:

• Commonest feature is generalized osteopenia, (osteopenia and high ESR in patient above 50 is MM until proved otherwise).

• Sometimes multiple punched-off small defects in more than one bone.

• Vertebrae can show compression fractures.

Investigations

• CBP+ESR.

• Urine for Benz Jones protein.

• Serum&urine protein electrophoresis.

• Bone marrow aspirate and biopsy.

Treatment

• Radiotherapy and chemotherapy controls the abnormal growths, relieve pain and pressure and improves survival.

• Pathological fractures treated with curettage & internal fixation +/- bone cement.

• Spinal lesions and cord or root pressure needs decompression +/- bone fusion.

Metastatic bone tumors:

• Its more common than all primary malignant bone tumors together.

• Mainly from Ca-breast, lung, prostate, kidney, thyroid or others.

• The primary sometimes cannot be found.

• Lesions appear in areas of red marrow as shaft of long bones, spine or pelvis.

• They destroy and replace bone, they grow rapidly and there is no bone reaction.

Clinical features:• Age usually 50-70 years.• Commonly there is pain of long bones

spine or pelvis.• Sometimes present as pathological

fractures.• We may look for the primary source with

clinical exam, imaging, laboratory tests and all possible means.

• If primary source is not obvious no need for further effort to find it because it does not affect final treatment a lot.

X-ray:• Pure destructive osteolytic lesion

usually in the diaphysis gives a Moth-Eaten appearance without any bone reaction.

• Generalized osteopenia is common.

• Chest X-ray or pulmonary CTscan can exclude lung metastasis.

• Generalized bone scan can show other skeletal lesions.

Treatment • As metastasis already occurred the

prognosis is always poor and treatment is usually palliative.

• Patient may need radio+/- chemotherapy plus support of the general condition.

• A pathological fracture needs curettage, internal fixation +/-bone cement.

• Spinal lesions and cord or root compression may need decompression +/- bone fusion.