brown tumours , an unusual but recognized complication of both primary and secondary hyperparathyroidism , have been reported to occur in 4.5% of patients with primary and 1.51.7% of those with secondary disease . a frail 57-year - old male haemodialysis patient with known severe peripheral vascular disease presented to the vascular surgeons with a 4-week history of worsening leg weakness . a magnetic resonance imaging ( mri ) scan of the spine ( figure 1 ) showed multiple lesions , the largest of which was at t12 , causing cord compression . this showed portions of bone containing a cellular spindle cell proliferation with abundant brown , granular and globular material and scattered groups of multinucleate giant cells of the osteoclast type , which , in the context of high parathyroid hormone levels , was diagnosed as a brown tumour of hyperparathyroidism . despite significant cord compression , he was initially commenced on increased medical therapy for his secondary hyperparathyroidism including cinacalcet . however , after 6 weeks the patient had not responded to treatment , and he therefore underwent a four - gland parathyroidectomy . brown tumours ( or osteoclastomas ) are an unusual but recognized complication of both primary and secondary hyperparathyroidism and have been reported to occur in 4.5% of patients with primary and 1.51.7% of those with secondary disease . they are composed of multinucleated osteoclasts , stromal cells and matrix [ 2 , 3 ] and are benign in nature , although they can cause significant morbidity due to secondary effects such as spinal cord compression . the name derives from their vascularity , haemorrhage and consequent haemosiderin deposition , which give these tumours their characteristic colour [ 2 , 3 ] . brown tumours are histologically similar to other giant cell tumours and diagnosis therefore depends on the histological findings along with a raised pth level [ 1 , 4 , 5 ] . in terms of the underlying pathology , brown tumours are a localized form of osteitis fibrosa , the classical histological form of high - turnover renal osteodystrophy . they most commonly arise from the tuberous parts of the jaw , and in long bones and ribs . spinal cord lesions are less common [ 57 ] and historically reported more frequently in patients with primary hyperparathyroidism . however , a recent literature review noted increased reporting of vertebral brown tumours in patients with esrd over the last few decades for which this may simply reflect increased reporting or be a marker of increased survival in dialysis populations resulting in a true increase in the incidence of cases . the first case of brown tumours involving the spine in a haemodialysis patient was reported in 1978 by ericsson et al . . in total and excluding the case presented here , 36 other cases of spinal cord compression secondary to brown tumours have been reported in the literature ( table 1 ) . of these , 64% ( 23 of 36 ) of cases have been reported in patients with secondary hyperparathyroidism due to chronic kidney disease ( ckd ) . all cases presented with signs and symptoms of cord compression , 77.8% ( 28 of 36 ) had surgical resection of tumour and 69.4% had parathyroidectomy . table  1.summary of the spinal brown tumour cases reported in the literatureyear publishedsex / age ( years)hyperparathyroidismspine involvedsymptomstreatmentshaw and davies 1968f/58primaryt10 pedicleparaparesis and urinary retentionsurgical resection and parathyroidectomyshuangshoti et al . 1972m/32primaryl4 posterior elementsprogressive paraparesis and reticular painsurgical resection and parathyroidectomysundaram and scholz 1977f/63primaryt10 body and pedicleparaplegia and t7 bodiesparaparesissurgical resection and parathyroidectomybarlow and archer 1993f/31secondarycervicalneck pain and cervicobrachial neuralgiaparathyroidectomy and minerva jacketsarda et al . 2012m/47secondarylumboscralback pain and difficulty in gaitposterior laminectomy and tumour excision summary of the spinal brown tumour cases reported in the literature vertebral brown tumours can either present acutely due to cord compression with progressive neurological deficit or with symptoms caused by vertebral fracture [ 1 , 4 ] . radiological findings depend on the modality used . on plain x - rays , brown tumours usually present as an osteolytic lesion [ 1 , 10 ] . in the long bones , these are usually well demarcated but in the spine the margins can be difficult to see . a computed tomography scan can confirm an osteolytic lesion with no cortical disruption or periosteal reaction [ 1 , 5 ] but an mri scan will provide a far more detailed image and often demonstrates the fluid cysts which are a highly suggestive marker of a brown tumour . medical treatment includes aggressive dialysis , treatment with phosphate binders , vitamin d supplements and cinacalcet , although previous case reports have questioned the effectiveness of the latter [ 3 , 8 ] . parathyroidectomy is also commonly performed but requires a patient to be fit enough for a general anaesthetic . normalizing bone biochemistry and parathyroid hormone levels generally result in bone remineralization and resolution of the tumours . however , remineralization may not happen in a spinal lesion ; this is presumed to be due to the reduced amount of mechanical stress in comparison to long bones . in conclusion , the possibility of a brown tumour should form part of the differential diagnosis in patients with advanced kidney disease presenting with peripheral neurological symptoms and a mass lesion . this case demonstrates the need for a high index of suspicion and highlights the need for nephrologists to be involved in the ongoing care of dialysis patients admitted to other specialties .
brown tumours are an uncommon manifestation of primary and secondary hyperparathyroidism . 
 there are numerous case reports of brown tumours arising in various parts of the skeleton . 
 they can therefore present a wide range of clinical manifestations . 
 a recent case highlighted the need for heightened awareness of the diagnosis and prompted a literature review .