Application of Tissue Aspirate Parathyroid Hormone Assay for Imaging Suspicious Neck Lesions in Patients with Complicated Recurrent or Persistent Renal Hyperparathyroidism

Background: Comprehensive pre-reoperative localization is essential in complicated persistent or recurrent renal hyperparathyroidism. The widely used imaging studies sometimes lead to ambiguous results. Our study aimed to clarify the role of tissue aspirate parathyroid hormone (PTH) assay with a new positive assay definition for imaging suspicious neck lesions in these challenging scenarios. Methods: All patients with complicated recurrent or persistent renal hyperparathyroidism underwent parathyroid sonography and scintigraphy. Echo-guided tissue aspirate PTH assay was performed in suspicious lesions revealed by localization imaging studies. The tissue aspirate PTH level was determined by an immunoradiometric assay. We proposed a newly-developed definition for positive assay as a washout level higher than one-thirtieth of the serum PTH level obtained at the same time. The final diagnosis after re-operation was confirmed by the pathologists. Results: In total, 50 tissue aspirate PTH assays were performed in 32 patients with imaging suspicious neck lesions, including discrepant results between scintigraphy and sonography in 47 lesions (94%), unusual locations in 19 lesions (38%), multiple foci in 28 lesions (56%), and locations over previously explored areas in 31 lesions (62%). Among 39 assay-positive lesions, 13 lesions (33.3%) were not identified by parathyroid scintigraphy, and 28 lesions (71.8%) had uncertain parathyroid sonography findings. The final pathology in patients who underwent re-operative surgery proved the tissue aspirate PTH assays had a 100% positive predictive value. Conclusions: Our findings suggest tissue aspirate PTH assay with this new positive assay definition is beneficial to clarify the nature of imaging suspicious lesions in patients with complicated persistent or recurrent renal hyperparathyroidism.

Hyperparathyroidism presenting as acute pancreatitis: Case Report of mortality

Background: Acute pancreatitis may be caused by a myriad of factors, hypercalcemia secondary to hyperparathyroidism, albeit is a rare cause of acute pancreatitis but not unheard of. If the underlying cause of acute pancreatitis is diagnosed, goal-directed management becomes possible, reducing morbidity and mortality. Though acute pancreatitis on its own presents significant mortality, hypercalcemia, especially detected late, augments this. Case Report: We report a case of acute pancreatitis secondary to hyperparathyroidism. The patient was undiagnosed at the time of admission and presented with non-specific gastrointestinal symptoms. After admission, he developed multi-organ dysfunction and was managed by intensive care. The patient died within hours of admission despite our best efforts. Diagnosis of acute pancreatitis secondary to hyperparathyroidism was suspected on the basis of hypercalcemia, confirmed by a posthumous result of a raised parathyroid hormone assay. Conclusion: When a patient is admitted in the emergency department with a suspicion of acute pancreatitis, serum calcium levels and its reporting should be expedited to as early as possible. Hypercalcemia in the setting of acute pancreatitis merits a multidisciplinary approach and expedited parathyroid hormone levels sent with a high suspicion of long standing untreated hyperparathyroidism. Hyperparathyroidism is a cause of silent hypercalcemia and can be lethal if not diagnosed in time.