Clinical Images: Increased bone metabolism in secondary hyperparathyroidism.

Abstract

The patient, a 47-year-old man, was diagnosed as having severe hyperparathyroidism secondary to end-stage kidney disease (ESKD), the underlying cause being leukocytoclastic vasculitis with IgA nephritis and minimal-change glomerulonephritis, which was confirmed by kidney biopsy in 2008. The patient had been receiving hemodialysis since 2014 and had a history of multiple fractures. His treatment included azathioprine, low-dose prednisolone, calcium carbonate, vitamin D, sevelamer, cinacalcet, torasemide, carvedilol, amlodipine, moxonidine, simvastatin, low molecular weight heparin, and erythropoietin. After a sudden transitory episode of vision loss with increased C-reactive protein (18.1 mg/liter) and response to glucocorticoids, 18F–positron emission tomography/computed tomography (18F-PET/CT) evaluation was performed to rule out systemic vasculitis. Ophthalmologic examination was negative for arteritic ischemic optic neuropathy, ophthalmoparesis, loss of visual field, and diplopia. Imaging with 18F-PET/CT revealed enhanced fluorodeoxyglucose uptake in the skeleton (A and B) and thickening of cortical bone such as in the femurs (C). Bone loss as osteolytic lesions in the calvaria, increased uptake in the setting of diffuse skull thickening with loss of distinction between the inner and outer table (D), and increased uptake in mandible bones (E) could be seen. There was no evidence for vasculitis. ESKD is associated with a complex remodeling of bone, summarized as renal osteopathy (1). This might include bone resorption, periosteal reaction, brown tumors, osteoporosis, osteosclerosis, osteomalacia, and soft tissue/vascular calcifications. Imaging may reveal any number of these conditions (2, 3). In our patient, 18F-PET/CT revealed osteolytic lesions, which were considered brown tumors and interpreted as osteitis fibrosa cystica. The patient was hypocalcemic (adjusted serum calcium 1.90 mmoles/liter), with elevated alkaline phosphatase (758 IU/liter) and massively elevated parathyroid hormone levels (1,872 pmoles/liter), indicating severe secondary hyperparathyroidism. These 18F-PET/CT images reflect the widespread, strongly induced metabolic activity of bone in secondary hyperparathyroidism during ESKD. Disclosure Form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.