Malignant skeletal tumors

Skeletal malignant tumors are tumors of the bone and cartilage with a local tendency to destruct the bone and a distant metastatic potential

Osteosarcoma
Osteosarcoma is a primary malignant tumor of the bone (2nd most common bone tumor after multiple myeloma). Osteosarcoma mostly affect young patients aged between 10 and 25. Osteosarcoma typically grows in the metaphysis of long bones, most commonly in the vicinity of the knee.

Osteosarcoma can arise without any predisposition in the young patients but in the older population it usually arises due some predisposing factors as Paget's diseases, fibrosis, and dysplasia.

Locally, osteosarcoma destroys the bone and enters into the surrounding soft tissues around the bone. Distantly, it metastasizes hematogenously into the lungs, bones (skip metastasis) and the brain.

Classification

 * Central (medullary, conventional) osteosarcoma: is when the tumor grows in the marrow of the metaphysis and then infiltrates into the cortex bellow the periosteum or even into the surrounding soft tissues. Microscopically, osteoid formation is a hallmark of the disease. Osteoid is produced by neoplastic osteoblasts. Different proportions of osteoid, cartilaginous, fibrous and vascular tissues can develop and according we can classify it into
 * Fibroblastic: spindle shaped tumor cells are present. Osteoid is minimally present. High vascularization is also evident.
 * Chondroblastic: Neoplastic cartilaginous tissue is present with some atypical spindle cell elements
 * Osteoblastic: mineralized or non-mineralized osteoid islets or beams are present. Tumor osteoblasts are severely anaplastic (pathologically deformed cells)


 * Peripheral (superficial) osteosarcoma: Forms a painful protuberance on the bone surface. On x-ray secondary periosteal ossification is visible. One example is the parosteal (juxtacortical) osteosarcoma with very good prognosis.

Clinical picture

 * pain in the affected bone, typically resting and nocturnal (ie not associated with stress),
 * with tumor growth, solid swelling occurs, which may not be painful to the touch (typically around the knee joint),
 * in an advanced stage, pathological fractures of the relevant bone could occur,
 * non-specific general symptoms - night sweats, fever, weight loss,
 * cough and difficulty breathing - lung metastases

Diagnostics

 * Elevated phosphates levels are a biochemical marker for bone tumors
 * Simple x-ray
 * osteolysis and newly formed bone
 * cortical bone disruption
 * periosteal reaction in the form of Codman's triangle


 * bone MRI
 * Bone scan (scintigraphic bone examination)
 * Bone biopsy for histopathological examination and definite diagnosis not only of the tumor but also of the type.
 * Lung X-ray or CT, brain MRI to check for distant metastasis

Therapy

 * chemotherapy (Adriamycin, high dose Methotrexate, leucovorin, Cis-platin, Isophosphamide)
 * Radical surgical removal of the tumor (amputation or limb saving procedures)
 * Osteosarcoma are generally not radiosensitive so radiotherapy is rarely used

Prognosis
Patients with a radically cured tumor and a good response to chemotherapy has an 80% chance of cure. (tumor type, patient age, time of diagnosis, treatment effect all play a role in prognosis)

Ewing Sarcoma
Ewing's sarcoma (EWS) belongs to the sarcomas of the Ewing group: EWS, PNET (primitive neuroectodermal tumor), Askin's tumor (Ewing on the chest wall).

It is the 2nd most common malignant bone tumor in children and adolescents, the highest incidence in the period of 5–30 years.

It most often develops in the bone marrow of the diaphysis of long bones (main femur, tibia). Early metastasizes to the lungs is typical.

Clinical picture: It often mimics acute osteomyelitis: subfebrile, leukocytosis, increased sedimentation. Pain, swelling and pathological fractures are also common

Diagnosis:


 * X-ray image: osteolytic changes with permeative bone destruction + periosteal reaction.
 * Scintigraphy examination is positive

Therapy: 1. neoadjuvant CHT, 2. radical surgical resection, 3. intraoperative / subsequent RT, 4. adjuvant CHT.

Prognosis: 5-year survival 60-76% (in case of no metastases).

Chondrosarcoma
Chondrosarcoma is a chondrogenic tumor usually happening in the metaphysis of the proximal part of the humerus, femur , tibia , and pelvis

It arises primarily or secondary to Ollier's disease (multiple enchondromas)

typically affects older patients between the age of 30 and 70 years.

Clinically manifests as gradually increasing pain specially nocturnal, swelling, and a palpable mass

X-ray: intraosseous osteolytic lesion.

Histological picture: lobularly arranged masses of cartilaginous tissue with cellular atypia.

Therapy: the only treatment is surgical removal of the tumor: broad / radical resection of the tumor.

Multiple Myeloma
Multiple myeloma (MM) is a malignant tumor of the plasma cells. It is usually arising from the bone marrow, where it destroys the bones and the bone marrow. In MM several neoplastic foci develop. Neoplastic cells produce protein chains (immunoglobulin or parts of immunoglobulins) known as paraprotein.

Macroscopy
Myeloma takes the form of dark red osteolytic deposits in the bone marrow (calf, vertebrae, pelvis, humeral shaft, femur).

Complication

 * Pathological fractures (spinal cord lesions in the case of vertebrae).
 * AL amyloidosis.
 * Myocardium - arrhythmias, heart failure.
 * Large intestine - malabsorption.
 * Kidneys - renal failure ( proteinuria, periorbital edema, uremia ).
 * Liver, blood vessels, nodes…
 * Tongue - macroglossia.
 * Myeloma kidney - clogging of tubules by protein chains - Bence Jones protein.

It threatens the patient's life

 * Failure of an organ affected by amyloidosis,
 * bronchopneumonia - develops after vertebral fracture and spinal cord injury,
 * opportunistic infections after total bone marrow destruction

Ostatní vzácnější malignity skeletu

 * adamantinom dlouhých kostí
 * chordom
 * maligní fibrózní histiocytom
 * fibrosarkom
 * liposarkom

Související články

 * Benigní nádory skeletu