Primary hyperparathyroidism presenting as hypercalcemic crisis: Twenty-year experience

Abstract

Context: To study hyperparathyroid-induced hypercalcemic crisis (HIHC).

Aims: We see very advanced cases of primary hyperparathyroidism (PHPT) and therefore, we sought to determine the incidence of HIHC in our surgically-treated PHPT patients, clinical presentation, and short- and long-term results with the use of bisphosphonate therapy and expeditious parathyroidectomy over a 20-year period at a single institution.

Settings and design: Retrospective review of PHPT patients at Department of Endocrine Surgery, a tertiary care referral center.

Materials and methods: Retrospective review of 177 patients of advanced PHPT who underwent parathyroidectomy at a single institution from 1989 to 2010. All patients with serum calcium ≥14 mg/dl (≥3.5 mmol/l) were included in HIHC group.

Statistical analysis: Analysis of variance (ANOVA) was used to determine differences between groups. Data is expressed as mean ± standard error of the mean (SEM); P values less than 0.05 were considered significant.

Results: We observed a higher incidence of HIHC (n = 37, 21%) with higher incidence of pancreatitis (n = 5, 13.5%). Crisis patients had heavier (6,717 mg) glands. Use of bisphosphonate therapy in seven crisis patients resulted in quicker lowering of serum calcium (mean: 4.5 vs 14.6 days in other crisis patients, P = 0.027) permitting early surgery. The incidence of postoperative hypocalcemia was not higher in these patients. Although the parathyroid adenoma was common pathology in both the groups, the incidence of parathyroid carcinoma was higher in crisis group (10.8%). Outcome with regards to postoperative eucalcemia was similar in both groups.

Conclusions: Crisis patients are at risk of developing pancreatitis. Bisphosphonate therapy has the potential to quickly lower the serum calcium permitting early surgery without added risk of postoperative hypocalcemia. Successful and sustained eucalcemia with excellent long-term survival is possible with use of bisphosphonates and semi-emergent, focused parathyroidectmy.

Keywords: Bisphosphonate; hypercalcemic crisis; parathyroidectomy; primary hyperparathyroidism.

Figure 1

Histopathological findings of parathyroid adenoma in patients (control) with primary hyperparathyroidism without hyperparathyroidism-induced hypercalcemic crisis (HIHC), (a) Adenoma: Microphotograph showing absence of microcystic pattern, intracytoplasmic vacuoles, and intraglandular fibrosis (H and E, ×100 magnification), (b) Adenoma with capsule: Microphotograph showing thin capsule of parathyroid adenoma. There is absence of microcystic pattern, intracytoplasmic vacuoles, and intraglandular fibrosis (H and E, ×100 magnification)

Figure 2

Unique histopathological findings of parathyroid adenoma in patients with HIHC. (a) Microcystic pattern: Dilated follicles forming cysts (H and E, ×200), (b) Intracytoplasmic vacuoles: Cells of parathyroid adenoma showing intracytoplasmic vacuoles (H and E, ×400), (c) Intraglandular fibrosis: Thick fibrous bands traversing within the tumor (H and E, ×100), (d) Intraglandular fibrosis with thick capsule: Thick fibrous bands traversing within the tumor surrounded by thick fibrous capsule (H and E, ×100)