Mixed pheochromocytoma and adrenal cortical adenoma (corticomedullary adenoma) is extremely rare. We report a 41-year-old woman diagnosed preoperatively with Cushing syndrome of adrenal origin. Nonsuppressible serum cortisol and 24-hour urine free cortisol levels by a standard low-dose dexamethasone suppression test with a low plasma adrenocorticotropic hormone (ACTH) level suggested ACTH-independent Cushing syndrome. Magnetic resonance imaging (MRI) revealed a left adrenal mass about 4 cm in diameter, showing a slightly heterogenous signal drop in chemical shift imaging, suggesting high lipid content in the tumor. The T2-weighted image, however, had a mildly high signal, rather than the typical normal to low signal characteristic of a cortical adenoma. 131I-6β-iodomethyl-norcholesterol (NP-59) scintigraphy revealed early accumulation of radioactivity in the left suprarenal region, suggesting a functioning cortical tumor. The patient underwent left adrenalectomy, but the surgery caused a marked elevation of systolic blood pressure (greater than 200 mm Hg). The suspicion of pheochromocytoma was entertained. Mixed pheochromocytoma and adrenal cortical adenoma (corticomedullary adenoma) were disclosed by immunohistochemical stains and electron microscopic examination. This case is the fifth reported pathologically proven corticomedullary adenoma. We include special image findings that contain characteristics of both cortical and medullary components.
*Attending Physician, Division of Endocrinology and Metabolism, Department of Internal Medicine, Tauyuan Veteran Hospital, Tauyuan, Taiwan; and †Chief, Ultrastructural and Molecular Pathology, Pathology and Laboratory Medicine Department, ‡Attending Urologist, Division of Urology, Department of Surgery, and §Chief Resident and ¶Chief, Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
The authors have disclosed that they have no significant relationships with or financial interests in any commercial company that pertains to this educational activity.
Lippincott Continuing Medical Education Institute, Inc. has identified and resolved all faculty conflicts of interest regarding this educational activity.
Reprints: Hong-Da Lin, MD, Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Road, Taipei 11217, Taiwan. E-mail: firstname.lastname@example.org.
Chief Editor’s Note: This article is the 33rd of 35 that will be published in 2007 for which a total of up to 35 AMA PRA Category 1 Credits™ can be earned. Instructions for how credits can be earned precede the CME Examination at the back of this issue.