Osteosarcoma diagnostic delay associated with alendronate-induced pain relief.

A 32-year-old man with a painful osteoblastic osteosarcoma of the right hip was initially diagnosed as having Paget's disease of bone. He was treated with alendronate for presumptive Paget's disease. The patient's bone pain was dramatically reduced by the administration of alendronate for 7 months. Following discontinuation of alendronate, his pain promptly recurred, culminating in a more thorough evaluation that led to the correct diagnosis. Despite chemotherapy, the patient succumbed to metastatic osteosarcoma. The main purpose of this publication is to report the potential for pain relief when an osteosarcoma is treated with bisphosphonate medication. Clinicians are advised not to consider an alendronate-associated pain reduction in an osteoblastic lesion as an indicator of an underlying benign process of bone. The evaluation of painful sclerotic bone lesions is briefly reviewed.