Unusual functioning endocrine tumors
- 49 Downloads
Endocrine surgeons should maintain a high index of suspicion when patients are diagnosed with clinical signs or symptoms of parathyroid carcinoma. Although rare, the best chance for cure of these patients is at the time of the initial operation. Surgical resection of recurrent disease can provide effective palliation and can sometimes be assisted using gamma-probe directed dissection of sestamibi-labeled tumor tissue. Treatment of hyper-parathyroidism in the setting of multiple endocrine neoplasia type 1 (MEN-1), particularly in the reoperative setting, can be aided by using the rapid intraoperative parathyroid hormone assay to judge the adequacy of parathyroid debulking. In addition, in selected cases, the gamma probe can assist in identifying the location of ectopic or autografted sestamibi-labeled parathyroid tissue. Patients with incidental adrenal masses rarely require fine needle aspiration to exclude metastatic cancer. Fine needle aspiration, if performed, should never precede hormone evaluation to exclude pheochromocytoma. Patients who are diagnosed with incidental adrenal masses in the setting of a prior or concurrent cancer diagnosis are equally likely to have a primary adrenal mass as they would be to have metastatic cancer in the adrenal gland. Pheochromocytomas occasionally develop in patients with MEN-1. In suspicious cases, molecular identification of an MEN-1 mutation can be used to confirm the diagnosis. Preoperative hormone evaluation of a patient with an adrenal incidentaloma should include evaluation for subclinical Cushing’s syndrome through an overnight 1-mg dexamethasone suppression test. Identification of this condition allows for safe peri- and postoperative steroid hormone replacement, with very slow withdrawal of exogenous steroids to allow the opposite adrenal gland to recover and avoid postoperative Addisonian crisis. Paragangliomas are more commonly multifocal and malignant compared to pheochromocytomas. Evaluation of patients with paragangliomas should include radiographic staging for multifocality and metastatic disease, and postoperative hormone and radiographic follow-up evaluation should be performed. Consideration should be given to genetic testing for von Hippel-Lindau and succinate dehydrogenase mutations. Surgical treatment of rare functioning pancreatic and duodenal endocrine tumors, such as metastatic sporadic insulinoma and MEN-1-associated gastrinoma, can provide effective palliation. Surgical treatment should be integrated into a comprehensive treatment scheme that recognizes the natural history of the disease and incorporates appropriate adjunctive therapies and follow-up strategies.
Unable to display preview. Download preview PDF.
References and Recommended Reading
- 2.Grau AM, Evans DB, Hoff AO, Lee JE: Carcinoma of the parathyroid glands. In Endocrine Surgery of the Head and Neck. Edited by Pellitteri PK, McCaffrey TV. New York: Delmar Learning; 2003:429–440.Google Scholar
- 9.Neumann HP, Bausch B, McWhinney SR, et al.: Germ-line mutations in nonsyndromic pheochromocytoma? N Engl J Med 2002, 346:1459–1466. In this series of 271 patients who were diagnosed with nonsyndromic pheochromocytoma and without a family history of disease, nearly 25% of the patients had germline mutations in RET, VHL, SRHD, or SDH subunit B. Routine analysis for these genetic mutations in patients with apparently sporadic pheochromocytomas may be indicated.PubMedCrossRefGoogle Scholar
- 14.Norton JA, Fraker DL, Alexander HR, et al.: Surgery to cure the Zollinger-Ellison syndrome? N Engl J Med 1999, 341:635–644. In this National Cancer Institute series of 151 patients, 123 patients had sporadic gastrinomas and 28 patients had MEN-1. Patients with MEN-1 who underwent surgery had at least one imaged tumor 3 cm in diameter. No patient with MEN-1 was free of disease at 10 years.PubMedCrossRefGoogle Scholar
- 16.Thompson NW: Surgical treatment of the endocrine pancreas and Zollinger-Ellison syndrome in the MEN-1 syndrome? Henry Ford Hosp Med J 1992, 40:195–198. In contrast to the National Cancer Institute experience, an aggressive surgical approach in 11 patients with gastrinoma in the setting of MEN-1 resulted in normal serum gastrin levels in 10 of 11 patients after a follow-up time ranging from 3 months to 14 years.PubMedGoogle Scholar