• It is most commonly located in the distal femur, proximal tibia, metaphysis (knee region).
• It is the second most common primary malignant bone tumor in adults. It is the most common nonhematogenous primary bone tumor.
• It is common in 10-30 year old men.
• The most important finding is pain.
• It appears as a triangle where the tumor tissue breaks up the cortex (Codman triangle, sunlight).
• It most commonly metastasizes to the lung.
• Osteosarcomas are categorized as primary and secondary.
• Primary osteosarcomas are classified as classical osteosarcoma, low grade intramedullary osteosarcoma, parosteal osteosarcoma, periosteal osteosarcoma, high grade osteosarcoma, telangiectatic osteosarcoma and small cell osteosarcoma.
Osteosarcoma
• Secondary osteosarcomas are generally seen above the age of 50. It occurs in Paget's patients and in patients who have previously received radiotherapy.Paget's sarcoma usually occurs during the 6-8 decades of life.
• High grade: classic osteosarcoma, small cell osteosarcoma, high grade osteosarcoma
• Intermediate grade: Periosteal osteosarcoma
• Low grade ones: low grade osteosarcoma, parosteal osteosarcoma
• The rate of development of osteosarcoma in Paget's disease is 1%. It is most often located in the pelvis.
• Treatment: Surgery, chemotherapy, radiotherapy
Chondrosarcoma
• It is the second most common malignant tumor of bone of nonhematological origin after osteosarcoma.
• Primary chondrosarcoma is common between the ages of 40-60 and secondary chondrosarcoma between the ages of 25-45.
• It is most commonly seen in pelvis, proximal femur, proximal humerus. They are rarely seen in the hand and are the most common malignant tumor of this region. They come to the clinic with complaints of slowly growing and gradually increasing pain.
• The risk of secondary chondrosarcomas in ollier and mafucci syndrome is 25%. It is also known to develop from osteochondromas. This risk is around 1% if the lesion is single and 5% if there is more than one osteochondroma.
• Its radiological appearance is punctate, popcorn and comma-shaped calcification.
Ewing Sarcoma
• It is the 3rd most common nonhematological malignant bone tumors. It is the most common malignant bone tumor in children under 10 years of age. It is common between the ages of 5-25.
• It starts from the metaphysis of long bones and extends towards the diaphysis. It is quite rare in the African race.
• Pain, fever, erythema and swelling can be confused with osteomyelitis. On average, the diagnosis is 34 months after the onset of symptoms (partly due to the late arrival of the patient after the onset of symptoms and partly to the delay in the physician's correct diagnosis from the first visit).
• Leukocytosis, C-reactive protein and erythrocyte sedimentation rate increase.
• Classically, the appearance of onion skin is present in radiology. Small blue cells are detected in histology.
• There is a t(11;22) (q24;q12) translocation in 90% of cases. They are stained with periodic acid-Schiff positive due to the presence of intracellular glycogen.
Multiple Myeloma MM
• It is the most common primary malignant bone tumor.
• It is seen between the ages of 40-60.
• The most common clinical finding is pain.
• It causes bone fractures.
• The most common site of involvement is the vertebrae, followed by the hip and pelvic bones.
• There is Bence Jones proteinuria in the urine, an increase in the alpha 2, 3 or gamma region in the blood electrophoresis.
• A lytic lesion in the form of a punch hole can be seen in the bones. These lesions are most common in the skull bones.
Chordoma
• It develops from the embryonic remnants of the notochord.
• It is most commonly seen in the sacrococcygeal and sphenooccipital regions.
Malignant Fibrous Histiocytoma and Fibrosarcoma
• Even though they are different titles, the difference between them may not be very obvious sometimes. They occur most frequently in the distal femur and proximal tibia metaphysis. Pain is the main complaint.
Metastatic Bone Tumors
• Metastasis to bone occurs from breast, prostate, lung, kidney, thyroid and gastrointestinal system.
• The majority of bone metastases are osteolytic, while prostate and breast cancer metastases are osteoblastic.
