Tumor biology and incidence

  • Very rare for this tumor to be primary malignancy of bone
  • Majority of lesions are metastatic when present in bone
  • Combined with non-Hodgkin’s lymphoma, accounts for approximately 10% of malignant bone lesions

Age

Between 20 and 60 years old

Gender

Slight male predominance

Presentation

May present with bone pain, often present before lesion becomes radiographically evident

Physical findings

  • Possible associated swelling if lesion is close to skin
  • Lymphadenopathy may be present; usually precedes detection of osseous lesions

Plain films

Site
  • 50% of lesions found in spine, ribs, pelvis, or femur
  • Thoracolumbar spine most common site of spinal involvement
  • Axial skeleton more commonly affected than appendicular skeleton
Size

Variable

Tumor effect on bone
  • Lesion usually presents as lytic lesion with permeative features
  • Check anterolateral vertebral bodies and ribs for “gouge defects” created by pressure erosion of bone by enlarged paravertebral lymph nodes
Bone response to tumor
  • May be sclerotic reaction
  • Vertebral body may become entirely sclerotic, yielding an “ivory vertebra”
  • Periosteal reaction rare
Matrix

None

Cortex

Cortical erosion may be evident

Soft tissue mass

May be present in osseous lesions

Bone scan

Will often show multiple sites of osseous involvement

Gallium scan

  • Tumors often gallium-avid
  • Gallium scan useful as part of systemic staging to delineate bone, soft tissue, and nodal extent of disease
  • Gallium scan has been shown to be accurate, specific modality in evaluation of disease response following therapy

CT and MRI

  • MRI useful for delineating local tumor extent in bone and soft tissues
  • CT scan of affected bone very helpful in determining integrity of cortex
  • CT of mediastinum, abdomen, and pelvis part of the systemic staging for determining nodal and organ involvement

Differential diagnosis

  • Eosinophilic granuloma (younger patients)
  • Ewing’s sarcoma (younger patients)
  • Non-Hodgkin’s lymphoma
  • Multiple myeloma
  • Malignant fibrous histiocytoma
  • Fibrosarcoma
  • Metastasis

Pathology

  • Gross: Firm tan tissue
  • Microscopic: Identification of Reed-Sternberg cells in appropriate background of eosinophils, lymphocytes, and plasma cells
  • Variable amounts of fibrosis present
  • Immunostaining for CD30 may help identify Reed-Sternberg cells

Diagnosis and treatment

  • Biopsy  required to obtain tissue for diagnosis
    • Gallium scan may demonstrate nodal tissue that may be biopsied in preference to bone
  • Treatment generally involves multi-agent chemotherapy and radiation
  • Radiation may be given to control bone pain or attempt to avert impending pathologic fracture
  • Surgery usually reserved for osseous complications arising secondary to osseous involvement:
    • Treatment of a pathologic fracture
    • Prevention of an impending pathologic fracture