Spontaneous Near-Remission of Hyperparathyroidism after Parathyroid Crisis

ABSTRACT Objective: To describe an unusual case of primary hyperparathyroidism due to a benign cystic parathyroid adenoma involving parathyroid crisis, profoundly elevated serum calcium and parathyroid hormone levels, and near-remission prior to surgery. Methods: We describe the presentation, evaluation, and treatment of an elderly female with parathyroid crisis due to a benign cystic parathyroid adenoma. Issues related to management of parathyroid crisis, parathyroid cancer, and atypical parathyroid lesions are highlighted. Previously reported cases of spontaneous remission of hyperparathyroidism are briefly reviewed. Results: Our patient was admitted with altered mental status, palpable neck mass, serum calcium level of 22.5 mg/dL, and parathyroid hormone level of 3,131 pg/mL. After immediate stabilization maneuvers, evaluation and treatment proceeded under a presumptive diagnosis of parathyroid cancer. Prior to surgery, parathyroid hormone level had spontaneously reduced by 20-fold. Resection of the parathyroid tumor with en bloc ipsilateral thyroid lobectomy was performed. Pathology demonstrated a benign cystic parathyroid adenoma. Conclusion: To the best of our knowledge, this is the only case of spontaneous near-remission days following admission for parathyroid crisis in which the diagnosis of benign adenoma was confirmed by pathology. This report may therefore contribute to an improved understanding of the natural history of primary hyperparathyroidism associated with atypical parathyroid lesions. The presenting serum calcium and parathyroid hormone levels in this case are among the highest ever reported for primary hyperparathyroidism due to benign adenoma and are at the upper end of values typically observed with parathyroid cancer. Abbreviations: PHPT primary hyperparathyroidism PTH parathyroid hormone