Positive Tc-99m-MIBI scan in a patient with confirmed Paget's disease of bone

A 46-year-old man was referred to our department for a Tc-99m MDP bone scan after he was admitted to our hospital with diffuse bone pain and the subsequent finding of multiple mixed type (lytic-blastic) lesions on routine x-rays. The Tc-99m MDP scan was highly suspicious for malignancy and, therefore, a Tc-99m MIBI scan was performed, which also revealed abnormal uptake in all regions with increased osteoblastic activity. Clinical chemistry and further workup revealed a highly elevated serum alkaline phosphatase and increased excretion of hydroxyproline in the urine. The presumed diagnosis of Paget's disease of the bone was further confirmed by biopsy.