Unusual Case of Autoimmune Diabetes Mellitus in the Setting of Extra-Adrenal Paraganglioma with Loss of Succinate Dehydrogenase Expression

Abstract

ABSTRACT Objective: To report a case of a catecholamine-secreting paraganglioma with possible tumor-dependent autoimmune diabetes mellitus. Methods: We present the imaging, laboratory, and pathologic findings and describe the clinical course of a patient with a norepinephrine-secreting aortic paraganglioma with succinate dehydrogenase deficiency who was concomitantly diagnosed with latent autoimmune diabetes of adults at the time of initial diagnosis. We performed immunohistochemistry on the paraganglioma tissue for glutamic acid decarboxylase-65 (GAD65). Results: A 55-year-old man was diagnosed with a retroperitoneal, norepinephrine-secreting paraganglioma. He was concomitantly found to have elevated serum glucose levels and positive anti-GAD65 antibodies, consistent with latent autoimmune diabetes of adults, and was started on a basal-bolus insulin regimen. Surgical removal of the tumor resulted in rapid improvement of his hypertension and glycemic control, eliminating the need for insulin therapy withi...