Atypical Paget's disease with quantitative assessment of tracer kinetics.
BACKGROUND
Paget's disease of bone is characterized by alterations in skeletal metabolism, affecting a single or multiple bones. Paget's is usually confined to an individual bone and typically does not spread or extend across joints. A patient with an unusual pattern of disease is presented together with quantitative assessment of the tracer kinetics pre- and posttreatment.


METHODS
A 75-year-old lady patient presented to her general practitioner in May 2002 with a history of lethargy. Clinical examination was unremarkable and further investigations such as blood tests (alkaline phosphatase levels), Tc-99m MDP bone scan, biopsy, and CT scan were carried out.


RESULTS
Alkaline phosphatase levels were greater than 2000 IU/L (Normal: 31-116 IU/L). The Tc-99m MDP bone scan showed strikingly increased uptake in the central skeleton involving the thoracic vertebrae and the adjoining ribs. The bone biopsy was inconclusive. CT scan revealed symmetrical expansion of the ribs with bridging osteophytes across the ribs and spine. The patient was treated with risedronate and quantitative analysis of the pre- and posttherapy bone scans showed reduced plasma clearance in the pagetic bones.


CONCLUSIONS
This case illustrates an unusual distribution of bone lesions in Paget's disease, which we think could be due to the result of degenerative disease leading to bridging and allowing direct extension of disease from one bone to another.
Gnanasegaran
Gopinath
G
Department of Nuclear Medicine, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK. gopinath.gnanasegaran@gstt.nhs.uk
Moore
Amelia E
AE
Blake
Glen M
GM
Vijayanathan
Sanjay
S
Clarke
Susan E
SE
Fogelman
Ignac
I
D000368:Aged; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D008657:Metabolic Clearance Rate; D010001:Osteitis Deformans / Q000000981:diagnostic imaging* / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D013669:Technetium Tc 99m Medronate / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate