Metabolic Superscan on 18F-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 18F-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.

Case report: 18F-FDG PET/CT skeletal superscan-like in an adult patient with acute lymphoblastic leukemia

“…This feature “looks too good” due to the diffuse and symmetric skeletal uptake, similar to the appearance of a bone scan. To date, diffuse tracer uptake in the skeleton/bone marrow as a skeletal superscan pattern on 18 F-FDG PET/CT has been previously reported in hematological diseases (including two cases of multiple myeloma ( 12 , 13 ), two cases of lymphoma and two cases of acute lymphoblastic leukemia ( 6 , 14 – 16 ), and one case of hemophagocytic lymphohistiocytosis) ( 17 ), nine cases of solid tumors with extensive bone metastasis ( 11 , 18 – 25 ), and metabolic diseases with three cases of hyperparathyroidism and one case of renal osteodystrophy ( 26 – 29 ). By reviewing all the medical images of the reports, the hematological diseases revealed greater homogeneous radiotracer uptake in the skeleton, as in our case, and the metabolic diseases all had a specific skull and mandible intense uptake pattern.…”