AB185. SOH24AB_063. Cystic parathyroid adenoma in female with stage IV chronic kidney disease: primary or 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 long-standing chronic kidney disease, raising the possibility of tertiary hyperparathyroidism. Methods: Having failed conservative management, a minimally invasive parathyroidectomy was performed with intra-operative parathyroid hormone level testing in the case of a 65-year-old female with hypercalcemia and elevated parathyroid hormone on a background of stage IV chronic kidney disease. Results: A bilobed cystic parathyroid adenoma was excised with an appropriate reduction in parathyroid hormone level. Conclusions: Cystic parathyroid adenomas are a rare cause of hyperparathyroidism and usually present with signs and symptoms of elevated calcium and parathyroid hormone levels. Accurate diagnosis is challenging, requiring a combination of laboratory investigations and imaging. Management commonly involves surgical resection, especially following failed conservative treatments.