Abstract 149: Multiple brown tumours as a manifestation of tertiary hyperparathyroidism in a patient with chronic kidney disease

Background: Brown tumours are lytic lesions of bone that occur due to increased osteoclastic activity and are seen in group of parathyroid disorders (primary, secondary, tertiary). Tertiary hyperparathyroidism due to chronic kidney disease is a rare cause of brown tumours. Case Report: A 22-year-old lady was diagnosed with chronic kidney disease in 2017. She was on maintenance hemodialysis. She developed swelling in left side of jaw 4 years ago. Swelling was progressively increasing in size and was painful. On evaluation, orthopantomogram showed a lytic lesion in left side of mandible. Later she developed more swellings in left elbow, right side of jaw. Serum calcium was 10 mg/dL, serum phosphorous was 4.8 mg/dL, PTH was 1565 pg/mL, serum alkaline phosphatase was 438 IU/L. Tc99m MIBI parathyroid scan could not detect any parathyroid adenoma, but showed lytic lesions in left part of mandible and right maxilla. F18 NaF bone scan showed lytic lesions in left part of mandible, right maxilla, left 9 th rib, left proximal ulna, left superior pubic ramus and proximal end of left tibia. She was started on tab cinacalcet 30 mg, but she had poor drug compliance. After 10 months her serum PTH was 926 pg/mL, but there was no decrease in size of jaw swelling. She was advised surgery for brown tumour excision injawandwasadvisedtocontinuecinacalcet. Conclusion: Uncontrolled hyperparathyroidism for prolonged period leads to brown tumours. Brown tumour excision is required when size doesn't decrease despite adequate medical management or when it is large enough to cause functional impairment.