Lytic metastasis to left L1-L2 pedicles with pathological vertebral compression fracture from unknown primary tumor.
Metastases are most common malignant bone tumors
Metastases are most common malignant bone tumors
Most involve axial skeleton
- Skull, spine and pelvis
- Rarely do metastasis 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=â€pedicle-signâ€
90% of skeletal metastasis are multiple
- The next four lesions comprise 80% of all metastases to bone
- Breast (70% of bone metastasis in women)
- Lung
- Prostate (60% of all bone metastasis 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, metastasis 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
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