Introduction Metastatic cancer is the most common reason for a destructive bone lesion in adults bone is the third most common site for metastatic disease (behind lung and liver) carcinomas that commonly spread to bone include breast lung thyroid renal prostate Metastatic hypercalcemia a medical emergency treat with hydration and loop diuretics epidemiology Age & location metastatic bone lesions are usually found in older patients (> 40 yrs) common sites of metastatic lesions include axial skeleton (vertebral bodies, pelvis, ribs) proximal limb girdle proximal femur is most common site of fracture secondary to metastatic bone lesions etiology Mechanism mechanism of bone destruction (osteolysis) metastatic bone destruction (causing osteolytic bone lesions) is caused by tumor induced activation of osteoclasts occurs through the RANK, RANK ligand (RANKL), osteoprotegrin pathway mechanism of tumor metastasis metastasis requires tumor cell intravasation avoidance of immune surveillance target tissue localization extravasation into the target tissue induction of angiogenesis genomic instability decreased apoptosis Presentation Symptoms pain may be mechanical pain due to bone destruction or tumorigenic pain which often occurs at night pathologic fracture occurs at presentation in 8-30% of patients with metastatic disease malignant hypercalcemia confusion polyuria & polydipsia nausea/vomiting dehydration Physical exam metastatic hypercalcemia muscle weakness Imaging Radiographic characteristics purly lytic or mixed lytic/blastic lesions 30% of lung CA is blastic 60% of breast CA is blastic 90% of prostate CA is blastic cortical metastasis are common in lung cancer lesions distal to elbow and knee are usually from lung or renal primary studies Workup for older patient with single bone lesion and unknown primary includes imaging plain radiographs CT of chest / abdomen / pelvis technetium bone scan labs CBC with differential ESR basic metabolic panel LFTs, Ca, Phos, alkaline phosphataseserum and urine immunoelectrophoresis (SPEP, UPEP) biopsy in patients where a primary carcinoma is not identified, obtaining a biopsy is necessary to rule out a primary bone lesion Histology Characteristic findings of metastatic lesions epithelial cells in clumps or glands in a fibrous stroma Immunohistochemical stains positive Keratin CK7 (breast and lung cancer) TTF1 (lung cancer) Treatment Nonoperative bisphosphonate therapy IV pamidronate prevents osteoclatic bone destruction dexamethasone prevents progressive neurologic injury with spinal cord compression radiation alone indications indicated in radiosenstive tumors such as breast cancer, prostate cancer, multiple myeloma and lymphoma indicated to shrink mets that are causing spinal cord compression Operative prophylactic IM nailing or arthroplasty with adjuvent radiation indications impending fx that meets criteria spinal neurologic decompression, stabilization, with postoperative radiation therapy indications metastatic lesions to the spine showing compression of neural elements and progressive neurologic deficits that are decreasing the quality of life in patient with life expectancy of greater than six months Differentials & Groups Malignant lesion in older patient(1)Multiple lesion in older patient(1)Epithelial glands on histologyBenefits from Bisphonate therapyTreatment is wide resection and radiation(2)Metastatic bone disease•••••Myeloma•••Lymphoma••Chondrosarcoma•MFH / fibrosarcoma•Secondary sarcoma•Pagets disease••Fibrous dysplasia•Synovial sarcoma•Hyperparathyroidism•Gomus tumor•Soft tissue sarcomas(3)•ASSUMPTIONS: (1) Older patient is > 40 yrs; (2) assuming no impending fracture (3) High-grade soft tissue sarcomas includes angiosarcoma, synovial sarcoma, liposarcoma, desmoid tumor, MFH/fibrosarcoma: exception is rhabdomysarcoma which is treated with chemotherapy and wide resection LocationXrayXrayCTB. ScanMRIMRIHisto(1)Case Aprox femurCase BpelvisCase Chand (thyroid CA)Case Dhand (lung CA)Case Efemur (lung CA)Case FpelvisCase Grenal CA (angio) Prognosis Median survival in patients with metastatic bone disease thyroid: 48 months prostate: 40 months breast: 24 months kidney: variable depending on medical condition but may be as short as 6 months lung: 6 months