Author(s)
Colin D.F. Cotton, BA
Robert P. Baughman, MD
Abid Yaqub, MD
Alice Tang, MD
Tammy M. Holm, MD PhD
David L. Steward, MD
Affiliation(s)
University of Cincinnati College of Medicine;
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to determine the etiology of hypercalcemia in patients with possible primary hyperparathyroidism and/or granulomatous disease.
Objectives: Primary hyperparathyroidism and granulomatous diseases are relatively common causes of hypercalcemia, which can cause diagnostic challenges if coexistent. We compare three patients with hypercalcemia and sarcoidosis and/or primary hyperparathyroidism.
Study Design: Retrospective review.
Methods: Clinical and laboratory data from three patients with hypercalcemia referred for parathyroidectomy were collected and compared.
Results: Patients 1 and 2 were 78 and 79 y/o females with histories of sarcoidosis presenting with asymptomatic hypercalcemia (11.2 and 11.5mg/dL, respectively), variable 25(OH)D (22.4 and 29.5ng/dL), variable 1,25(OH)2D (15.4 and 108pg/mL), and elevated iPTH (112 and 152mg/dL). Single hypercellular parathyroid glands were identified on imaging and removed, with iPTH improvement intraoperatively (138 to 15pg/mL and 265 to 74pg/mL). Postoperatively, calcium normalized (9.4 and 9.6mg/dL). Patient 3 was a 61 y/o female with longstanding hypercalcemia (10.9mg/dL), low 25(OH)D (22.4ng/dL), elevated 1,25(OH)2D (75-109ng/mL), normal iPTH (24-38pg/mL), and upper-normal ACE (50U/L). Ultrasound demonstrated normal thyroid without enlarged parathyroid glands. Sestamibi scan was nonlocalizing. Chest CT identified calcified mediastinal lymph nodes consistent with granulomatous disease.
Conclusions: In patients with hypercalcemia and sarcoidosis, it is important to check PTH to exclude coexistent primary hyperparathyroidism, which may benefit from parathyroidectomy. In patients with hypercalcemia and suspected normo-hormonal primary hyperparathyroidism, a complete biochemical workup to exclude other causes is fundamental. Granulomatous disease should be suspected when 25(OH)D is low and 1,25(OH)2D is elevated in the presence of a low-normal PTH level, as vitamin D conversion occurs by macrophages (extrarenal and not under PTH regulation). Neck and chest imaging may contribute to the assessment but the evaluation is predominantly biochemical.