Kim, Rachel C.Roch, Alexandra M.Birdas, Thomas J.Ritter, Hadley E.McDow, Alexandria D.2023-01-202023-01-202021-02-04Kim RC, Roch AM, Birdas TJ, Ritter HE, McDow AD. Hypercalcemic Crisis Caused by a Parathyroid Mass Requiring Thoracoscopic Resection. AACE Clin Case Rep. 2021;7(4):264-267. Published 2021 Mar 4. doi:10.1016/j.aace.2021.02.004https://hdl.handle.net/1805/30977Objective: To describe the presentation, work up, and treatment of a giant parathyroid adenoma presenting as hypercalcemic crisis that ultimately weighed 57 g and extended into the mediastinum, requiring hand-assisted thoracoscopic resection. Methods: The patient is a 68-year-old man with a prior history of parathyroidectomy, who initially presented with a severe hypercalcemia of 16.3 mg/dL and a parathyroid hormone (PTH) level of 2692 pg/mL on routine labs. Results: Diagnostic and staging work up revealed a 7.2-cm mass extending from just superior to the sternal notch into the right posterior mediastinum to the carina, causing esophageal displacement. No evidence of local invasion or distant metastasis was observed on further imaging, and cytology demonstrated hypercellular parathyroid tissue. The PTH level of the aspirate was >5000 pg/mL. The patient subsequently underwent a right hand-assisted video-assisted thoracoscopic resection of the intrathoracic mass. Final pathology identified a 7.0-cm, 57-g parathyroid adenoma, without any pathologic findings suspicious for malignancy. However, the endocrine surgery team plans for annual laboratory assessment to ensure no recurrence. Conclusion: Primary hyperparathyroidism is most commonly caused by a single adenoma. However, in the setting of severe hypercalcemia and elevated PTH, one must have a high suspicion for malignancy, and care should be taken to remove the mass en bloc. For extremely large adenomas extending into the mediastinum, a minimally invasive, hand-assisted, thoracoscopic approach is a safe and effective method of resection.en-USAttribution-NonCommercial-NoDerivatives 4.0 InternationalGiant parathyroid adenomaHypercalcemic crisisPrimary hyperparathyroidismThoracoscopic resectionArticle