Giant cell tumor of bone (GCT) is a rare, aggressive non-cancerous (benign) tumor. It generally occurs in adults between the ages of 20 and 40 years. Giant cell tumor of bone is very rarely seen in children or in adults older than 65 years of age. Giant cell tumors occur in approximately one person per million per year.

Giant cell tumors are named for the way they look under the microscope. Many "giant cells" are seen. They are formed by fusion of several individual cells into a single, larger complex.

Many bone tumors and other conditions (including normal bone) contain giant cells. Giant cell tumor of bone is given its characteristic appearance by the constant finding of a large number of these cells existing in a typical background. Most bone tumors occur in the flared portion near the ends of long bone (metaphysis), but giant cell tumor of bone occurs almost exclusively in the end portion of long bones next to the joints (epiphysis). In rare cases, this tumor may spread to the lungs.

Giant cell tumors of bone occur spontaneously. They are not known to be associated with trauma, environmental factors, or diet. They are not inherited. In rare cases, they may be associated with hyperparathyroidism.

agent Pharmaceuticals, Inc., a privately held specialty pharmaceutical company, today announced that it has launched pamidronate disodium injection in single-dose vials containing 30 mg per 10 mL and 90 mg per 10 mL.  Pamidronate disodium injection, the generic alternative of Novartis Pharmaceutical Company's Aredia®, is a bone resorption inhibitor.  The 2008 U.S. market for pamidronate disodium approximated $17 million, according to IMS data.
"Pamidronate is an important adjunctive therapy for cancer patients for the treatment of chemotherapy-associated osteoporosis," said Jeffrey M. Yordon, chief executive officer, founder, and chairman of the board of Sagent. "It will be a valuable addition to Sagent's oncolytic and supportive care product line, and we believe we are well positioned to serve this market."

Pamidronate disodium is indicated for the treatment of moderate or severe hypercalcemia associated with malignancy, with or without bone metastases. Patients who have either epidermoid or non-epidermoid tumors respond to treatment with pamidronate disodium. Secondly, pamidronate disodium is indicated for the treatment of patients with moderate to severe Paget's disease of bone. Thirdly, it is indicated, in conjunction with standard antineoplastic therapy, for the treatment of osteolytic bone metastases of breast cancer and osteolytic lesions of multiple myeloma.