Sestamibi scanning and outcomes in minimally invasive parathyroidectomy.

OBJECTIVE: To determine whether preoperative sestamibi scanning facilitates the desired outcome of successful completion of minimally invasive parathyroidectomy (MIP) and also to analyze the results in patients with underlying concurrent thyroid disease. METHODS: We undertook a retrospective analysis by review of medical records of 133 parathyroidectomies for sporadic primary hyperparathyroidism with preoperative sestamibi scanning during a 26-month period at our medical center. RESULTS: Of the 133 patients with preoperative sestamibi scanning, 106 were candidates for MIP, and 86 had positive scans showing a localized focus of uptake. MIP, with use of intraoperative parathyroid hormone level monitoring, was successfully completed in 70 patients; the other 16 patients required conversion to bilateral neck exploration. Another 20 patients with negative sestamibi scans (no localized focus of uptake) also underwent MIP. The surgeon used ultrasonography or subtle, nondiscrete sestamibi scan findings to decide on this approach. In this group, 65% of patients had successful completion of MIP, in comparison with 81% (95% confidence interval, 72% to 89%) in the group with positive scans (P = 0.13). Subgroup analysis of patients with underlying concomitant thyroid abnormalities showed successful completion of MIP in 39 of 51 (76%), in comparison with 31 of 35 patients (89%) without thyroid abnormalities (P = 0.16). CONCLUSION: In patients with sporadic primary hyperparathyroidism, finding a localized focus of uptake on a preoperative sestamibi scan facilitates successful completion of MIP. In patients with underlying thyroid disease, positive sestamibi scans are still useful in completing MIP, but more patients in this group require conversion to bilateral neck dissection.

Cushing's syndrome from ectopic production of corticotropin by a metastatic gastrinoma.

OBJECTIVE: To present a case of a young woman with new-onset diabetes mellitus resistant to insulin attributable to Cushing's syndrome caused by ectopic production of corticotropin by a metastatic gastrinoma. METHODS: We summarize the clinical presentation and the pertinent laboratory values in a patient with Cushing's syndrome. A review of the literature regarding ectopic production of corticotropin by gastrinomas is also presented. RESULTS: A 26-year-old woman with dehydration, severe hyperglycemia, and hypokalemia was seen in consultation. The patient required large doses of insulin to control plasma glucose, and further work-up confirmed the presence of Cushing's syndrome caused by ectopic production of corticotropin from a metastatic gastrinoma. CONCLUSION: This case is unusual in that the patient was relatively young and the clinical presentation of Cushing's syndrome was dominated by uncontrolled diabetes, insulin resistance, and hypokalemia. At the time of this diagnosis, the patient already had evidence of multiple liver metastatic lesions from a pancreatic gastrinoma. The rapid occurrence of difficult-to-treat diabetes and hypokalemia should raise the suspicion of Cushing's syndrome from ectopic production of corticotropin. In fact, patients with metastatic pancreatic tumors and poorly controlled diabetes with hypokalemia should undergo evaluation for Cushing's syndrome, even in the absence of the typical stigmas, because of rapid development of the disease and high levels of corticotropin.