Learning Radiology xray montage

Metastases to Bone
Renal Cell Carcinoma

    General Considerations 

    • Metastases are most common malignant bone tumors
    • Most involve axial skeleton
      • Skull, spine and pelvis
      • Rarely do mets occur distal to elbows or knees
    • Spread hematogenously
      • Most frequently occur where red bone marrow is found
      • Mets to spine frequently destroy posterior vertebral body including
        pedicle first=”pedicle-sign
    • 90% of skeletal mets are multiple
    • Primary carcinomas that frequently metastasize to bone
      • The next four lesions comprise 80% of all metastases to bone
        • Breast (70% of bone mets in women)
        • Lung
        • Prostate (60% of all bone mets in men)
        • Kidney
      • Also
        • Thyroid
        • Stomach and intestines
    • Clinical
      • Most lesions are asymptomatic
        • When symptomatic, pain is major symptom
      • Fractures of the lesser trochanter in adults should be considered
        pathologic until proven otherwise
    • Imaging Findings
      • In general, mets have little or no soft tissue mass associated with them
      • Usually no periosteal reaction
      • May appear as moth-eaten, permeative or geographic lesions
        • Indistinct zones of transition
        • No sclerotic margins
        • May be expansile
        • Soap-bubbly (septated)
        • May be sharply circumscribed or have indistinct borders
      • Metastases that are typically purely lytic
        • Kidney
        • Thyroid
      • Metastases that are usually mixed lytic and sclerotic
        • Lung
        • Breast
      • Metastases that are usually purely blastic
        • Prostate
        • Medulloblastoma
        • Bronchial carcinoid
      • No matter what the primary, skull metastases are usually lytic in appearance


    Most Common Tumors to Metastasize to Bone(80% of bone mets)
    Prostate Blastic
    Breast Mixed
    Lung Predominantly lytic
    Renal Cell Ca Predominantly Lytic


      • Imaging findings suggestive of a particular primary tumor
        • Lesions distal to elbows and knees
          • 50% are from lung and breast
        • Expansile and lytic (soap-bubbly)
          • Renal cell
        • Diffuse skeletal sclerosis or multiple round, well-circumscribed
          sclerotic lesions
          • Prostate
          • Breast
        • Cookie-bite lesions of the cortices of long bones
          • Lung
      • Radioscintographic studies
        • Bone scans are extremely sensitive but not very specific
        • 10-40% of lesions will not be visible on plain film but will be positive
          on bone scans
        • CT or MRI can be used to show findings in patients with negative
          conventional radiographs and positive bone scans
    • Complications of metastases to bone
      • Pathologic fractures
        • Destruction of 50% or more of bone suggests impending
          pathologic fracture
      • Spinal cord compression
      • Treated lytic mets may become sclerotic with treatment 

Metastases from Renal Cell Carcinoma. Frontal radiograph of the pelvis demonstrates a
huge, expansile osteolytic lesion destroying most of right ilium (yellow arrows). The lesion contains septa. Expansile metastases such as this generally occur with renal cell and thyroid carcinomas.

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For more information, click on the link if you see this icon

Orthopedic radiology: A Practical Approach, Greenspan, Ada; Lippincott, 2000
Diagnosis of Bone and Joint Disorders, Resnick, Donald, W. B. Saunders
Musculoskeletal Imaging: The Requisites, Manaster, BJ et al; Mosby, 2002