G HARLEY1, R RAJ1
1Launceston General Hospital, Launceston, Tasmania
Background: Lytic bone lesions in the elderly often raise the spectre of disseminated malignancy. Uncontrolled hyperparathyroidism can occasionally cause similar lesions as part of the spectrum of osteitis fibrosis cystica.
Case report: A frail 76-year old gentleman on maintenance haemodialysis for hypertensive nephropathy developed a clavicular fracture with minimal trauma after months of unexplained weight loss. He had a background of sustained hyperparathyroidism (iPTH >100picomol/L) but was too frail for parathyroidectomy and did not tolerate calcimimetics. Other medical issues included chronic diarrhoea, an episode of cardiac arrest and prolonged cardiopulmonary resuscitation from which he recovered and amaurosis fugax.
CT and X-ray investigations revealed multiple osteolytic lesions in the appendicular skeleton, left scapula and clavicle. These were in conjunction with heterogenous bone marrow pattern of the pelvis, osteodystrophy of the spine and a right pleural effusion with suspected mass lesion. Whole-body positron-emission tomography showed no uptake in the effusion or suspected pleural mass, focal increased uptake in the appendicular skeleton and diffuse uptake in the axial skeleton. Screening tests for multiple myeloma and prostate cancer were negative. A bone biopsy of his right fibular lesion showed numerous osteoclast-type giant cells consistent with brown tumours of hyperparathyroidism. He subsequently became progressively unwell and bed-bound because of severe bone pains. He eventually died after withdrawal from dialysis.
Conclusions: Formation of brown tumours represent a rare complication of longstanding uncontrolled hyperparathyroidism and should be considered in the differential diagnosis of any patient on long-term dialysis with multiple skeletal lytic lesions.