FULL HISTORY:

68-year-old woman with history of comminuted right humeral fracture eight months prior. She now presents with hypercalcemia and persistent right upper extremity pain along with swelling of the right upper extremity and right chest wall. A recent chest CT demonstrates a comminuted fracture of the proximal right humerus with a large adjacent fluid collection with possible soft tissue mass component. The patient has no known history of cancer.  Evaluate for primary or metastatic disease.

DIFFERENTIAL DIAGNOSIS: Localized bone scintigraphy uptake (Mettler, 2006)

trauma

degenerative changes (arthritis)

infection

primary bone tumor (benign and malignant)

metastatic disease

Paget's disease, fibrous dysplasia

hyperemia

overlying soft tissue activity

decreased overlying soft tissue (decreased attenuation)

DISCUSSION:

Pathologic fractures occur in bone that has been weakened secondary to a disease process, usually osteoporosis, although primary and secondary bone lesions, to include both benign and malignant etiologies can result in pathologic fractures.  Pathologic fractures can occur during normal activity or minor trauma secondary to the weakening of the underlying bone.  Pathologic fractures represent a serious co-morbidity in patients with osseous metastatic disease.  Prevention of pathologic fractures by utilizing proactive treatments can result in better patient outcomes, lower cost, and less difficult operative procedures.  Therefore, it is important to determine which lesions may require preventative treatment.  Many characteristics can be used for determining the risk of pathologic fracture including type of cancer, type of treatment, size of the lesion, location of the lesion, characteristics of the lesion and symptoms due to the lesion.