Common Primary Malignant Neoplasms of Bone

Common Primary Malignant Neoplasms of Bone 1. Osteosarcoma o Description: Most common primary malignant bone tumor. Typically occurs in adolescents and young adults. o Location: Often found in the metaphyses of long bones, especially around the knee (distal femur, proximal tibia). 2. Chondrosarcoma o Description: Second most common primary bone cancer. Occurs mainly in adults over 40. o Location: Commonly affects pelvis, femur, and shoulder girdle. 3. Ewing Sarcoma o Description: Highly aggressive tumor predominantly affecting children and adolescents. o Location: Diaphysis of long bones, pelvis, and chest wall. 4. Fibrosarcoma o Description: Rare, malignant fibroblastic tumor affecting older adults. o Location: Metaphysis of long bones and jaw. 5. Chordoma o Description: Rare, slow-growing tumor derived from notochord remnants. o Location: Axial skeleton, particularly the sacrum and skull base. Common Secondary (Metastatic) Malignant Neoplasms of Bone 1. Breast Cancer o Description: Most common source of bone metastases in women. o Location: Vertebrae, pelvis, ribs, and proximal femur. 2. Prostate Cancer o Description: Most common source of bone metastases in men. o Location: Vertebrae, pelvis, and proximal femur. 3. Lung Cancer o Description: High propensity to metastasize to bone. o Location: Axial skeleton, particularly the vertebrae. 4. Renal Cell Carcinoma o Description: Frequently metastasizes to bone. o Location: Vertebrae, pelvis, and proximal femur. 5. Thyroid Cancer o Description: Tends to metastasize to bone, though less common than breast or prostate cancer. o Location: Axial skeleton, particularly the vertebrae. Investigations 1. Imaging o X-ray: Initial assessment for bone lesions. Helps identify location, size, and nature of the lesion. CT Scan: Provides detailed images of bone structure, helpful in surgical planning. o MRI: Superior for soft tissue assessment and marrow involvement, essential for evaluating the extent of bone tumors. o Bone Scan (Scintigraphy): Useful for detecting bone metastases and multifocal bone lesions. o PET Scan: Assesses metabolic activity of the tumor, useful for staging and detecting metastases. 2. Biopsy o Core Needle Biopsy: Minimally invasive, used to obtain tissue sample for histopathological examination. o Open Biopsy: More invasive, performed if needle biopsy is inconclusive. 3. Laboratory Tests o Blood Tests: Complete blood count (CBC), alkaline phosphatase, lactate dehydrogenase (LDH), and calcium levels can provide information on tumor activity and bone turnover. o Tumor Markers: Specific markers depending on suspected primary source (e.g., PSA for prostate cancer, CA 15-3 for breast cancer). o Principles of Management 1. Multidisciplinary Approach o Team Involvement: Orthopedic surgeons, oncologists, radiologists, pathologists, and palliative care specialists collaborate for optimal patient care. 2. Surgery o Curative Resection: Aim to remove the entire tumor with a margin of healthy tissue. o Limb-Salvage Surgery: Preferred over amputation; involves resection of the tumor and reconstruction with prosthetics or bone grafts. o Amputation: Considered if limb-salvage is not feasible due to the extent of the tumor. 3. Radiation Therapy o Used for local control of tumor, especially in radiosensitive tumors like Ewing sarcoma. o Palliative radiotherapy for pain relief in metastatic bone disease. 4. Chemotherapy o Neoadjuvant (Preoperative): To shrink the tumor before surgical resection. o Adjuvant (Postoperative): To eliminate residual microscopic disease. o Standard for highly chemosensitive tumors like osteosarcoma and Ewing sarcoma. 5. Targeted Therapy and Immunotherapy o Emerging treatments for specific types of bone cancers and metastatic disease. o Example: Denosumab for giant cell tumor of bone. 6. Palliative Care o Pain management, fracture prevention, and maintaining quality of life in advanced disease stages. o Use of bisphosphonates or denosumab to strengthen bones and reduce skeletal-related events in metastatic bone disease. Effective management of bone neoplasms requires accurate diagnosis, comprehensive staging, and an individualized treatment plan tailored to the patient’s specific tumor type and overall health.