Renal osteodystrophy presenting as a metabolic superscan on F-18 FDG PET/CT: A case report

Metabolic Superscan on 18 F-FDG PET/CT in a Patient With Secondary Hyperparathyroidism

ABSTRACT

Superscan on PET/CT has been reported in the literature and mainly involved metastatic diseases. We report an uncommon case of a metabolic superscan on 18 F-FDG PET/CT in a 56-year-old man with end-stage renal disease on hemodialysis who presented with secondary hyperparathyroidism. Parathyroid scintigraphy showed 2 lesions posteroinferior to both thyroid lobes, suggestive of parathyroid adenoma/hyperplasia. FDG PET/CT performed to assess for pulmonary nodules revealed diffuse FDG hypermetabolism involving the visualized skull, mandible, spine, sternum, ribs, and appendicular skeleton without corresponding CT lesion with no urinary radiotracer excretion, consistent with metabolic superscan secondary to renal osteodystrophy.

Tertiary Hyperparathyroidism With Renal Osteodystrophy on 18F-Fluorocholine PET/CT

A 27-year-old man, with a history of chronic renal failure due to obstructive uropathy, treated with hemodialysis and awaiting kidney transplantation, presented with tertiary hyperparathyroidism. Despite regulation of phosphate and calcium and treatment with cinacalcet, the serum parathyroid hormone levels remained elevated. The patient was referred for parathyroidectomy, and a F-fluorocholine PET/CT was acquired for preoperative planning. Besides visualization of the hyperfunctioning parathyroid glands, the scan also showed a typical picture of renal osteodystrophy, a finding on F-fluorocholine PET/CT that has not been reported before.