Non-tumors

  • Brown’s tumors of hyperparathyroidism
  • Paget’s disease
  • Generalized osteopenia
  • Multifocal osteomyelitis

Benign

  • Familial osteochondromatosis (multiple hereditary exostoses)
  • Ollier’s disease
  • Maffucci’s disease
  • Polyostotic fibrous dysplasia
  • Histiocytosis X (eosinophilic granuloma, Hand-Schuller-Christian disease)
  • Non-ossifying fibroma

Malignant

  • Multifocal osteosarcoma
  • Chondrosarcoma arising in familial osteochondromatosis or Ollier’s disease
  • Multiple myeloma
  • Metastatic disease

Notes

  • Complete evaluation of the local radiograph will occasionally reveal multiple lesions. A bone scan is very useful in documenting the extent of skeletal involvement. Multiple lesions are, of course, most common in metastatic disease in patients over the age of 45. Combined with osteopenia, multiple lesions suggest myeloma
  • Paget’s disease should be suspected by the pattern of coarse disorganized trabeculae, cortical thickening, bony expansion, and the tendency of the radiographic changes to begin at one end of the bone.
  • Brown tumors are suggested by poorly defined metaphyseal lytic lesions combined with diffuse osteopenia and resorptive changes typical of hyperparathyroidism.
  • Patients with multiple exostoses generally have a family history of this autosomal dominant condition, although spontaneous mutations do occur. Because sessile osteochondromas occasionally resemble enchondromas, it may be necessary to search for typical exostoses to confirm the diagnosis of osteochondromatosis.
  • Polyostoticfibrous dysplasia has the tendency to be monomelic (confined to one extremity).

Other Differential Diagnoses by Anatomic Location