1064 Cystic Parathyroid Adenoma: A Rare Occurrence in Setting of Stage IV Chronic Kidney Disease with Tertiary Hyperparathyroidism

Background Cystic parathyroid adenomas represent a rare subtype of parathyroid adenomas characterised by cystic degeneration for which surgical intervention is the only curative treatment. Conservative medical management is a suitable option for patients with multiple comorbidities or mild symptoms. To our knowledge this is the first case of a bilobed cystic parathyroid adenoma in a patient with tertiary hyperparathyroidism secondary to long standing chronic kidney disease. Case presentation: A 65-year-old lady with stage IV CKD was referred to the endocrine surgical department having presented with hip pain. Investigations revealed hypercalcaemia, high parathyroid hormone in the setting of bilateral small echogenic kidneys. Imaging identified a bilobed parathyroid mass. 99m-technetium sestamibi scan confirmed a parathyroid adenoma. Having failed conservative management a minimally invasive parathyroidectomy was performed with histological analysis reporting a cystic parathyroid adenoma. Conclusions Cystic parathyroid adenomas are a rare cause of tertiary hyperparathyroidism and usually present with signs and symptoms of high calcium and high parathyroid hormone. Accurate diagnosis requires a combination of laboratory investigations and imaging. Management commonly involves surgical resection especially following failure of conservative treatments.