Non-tumor

  • Brown’s tumor of hyperparathyroidism

Benign

  • Osteoblastoma
  • Chondroblastoma
  • Aneurysmal bone cyst
  • Giant cell tumor (included as benign aggressive, although rarely metastases may occur)

Malignant

  • Telangiectatic osteosarcoma
  • Conventional osteosarcoma

Notes

  • Giant cell tumor is the most common diagnosis in this group.
  • Aneurysmal bone cyst should be suspected in patients with open growth plates and from fluid_fluid levels on MRI or CT.
  • Features of osteoblastoma, giant cell tumor, and aneurysmal bone cyst are often present on histology from the same tumor.
  • Always do serum calcium to rule out Brown’s tumor
  • If a large associated soft tissue mass is present, consider telangiectatic osteosarcoma
  • Classic (non-telangiectatic) osteosarcoma may extend across the physis in children or across the growth plate scar in skeletally mature individuals. It is recognized by the presence of osteoid formation and the development of a soft tissue mass on top of the intact cortex.

Other Differential Diagnoses by Anatomic Location