Predictors of recurrence in pheochromocytoma.

BACKGROUND: The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study aims to identify predictors of recurrence and optimal biochemical testing and imaging for detecting the recurrence of pheochromocytoma. METHODS: In this retrospective study we reviewed all patients who underwent adrenalectomy for pheochromocytoma during a 14-year period at a single institution. RESULTS: One hundred thirty-five patients had adrenalectomy for pheochromocytoma. Eight patients (6%) developed recurrent disease. The median time from initial operation to diagnosis of recurrence was 35 months. On multivariate analysis, tumor size >5 cm was an independent predictor of recurrence. One patient with recurrence died, 4 had stable disease, 2 had progression of disease, and 1 was cured. Recurrence was diagnosed by increases in plasma and/or urinary metanephrines and positive imaging in 6 patients (75%), and by positive imaging and normal biochemical levels in 2 patients (25%). CONCLUSION: Patients with large tumors (>5 cm) should be followed vigilantly for recurrence. Because 25% of patients with recurrence had normal biochemical levels, we recommend routine imaging and testing of plasma or urinary metanephrines for prompt diagnosis of recurrence.

The prevalence of undiagnosed and unrecognized primary hyperparathyroidism: a population-based analysis from the electronic medical record.

BACKGROUND: The electronic medical record (EMR) of a large, tertiary referral center was examined to study the prevalence of undiagnosed and unrecognized primary hyperparathyroidism (PHPT). METHODS: The EMR was queried for outpatient serum calcium >10.5 mg/dL over a 2-year period. RESULTS: Of 2.7 million patients, 54,198 (2%) had hypercalcemia (>10.5 mg/dL). In a 2-year sample of 7,269 patients, 1.3% (95 patients) had a recorded diagnosis of PHPT, and 0.3% (16 patients) had parathyroidectomy. Of the remaining patients, parathyroid hormone (PTH) values were recorded in 32% (2,337 patients). Of patients with PTH measured, 71% (1,662 patients) had PHPT (PTH > 30 pg/mL). Patients with calcium of 11.1­11.5 mg/dL were most likely to have PHPT (55%). Patients with calcium >12 mg/dL were most likely to have PTH measured (52%). Of hypercalcemic patients, 67% never had PTH obtained, 28% of whom were likely to have PHPT. It is estimated that 43% of hypercalcemic patients are likely to have PHPT. The estimated prevalence of PHPT in the general population is 0.86%. CONCLUSION: PHPT is a more common disorder than previously documented. It is crucial to evaluate even mild hypercalcemia, because 43% of these patients have PHPT. PHPT is underdiagnosed and undertreated.