FROM THE FILES OF THE AFIP Corticomedullary Mixed Tumor of the Adrenal Gland Jacqueline A. Wieneke, MD, Lester D.R. Thompson, MD, and Clara S. Heffess, MD Corticomedullary mixed tumors of the adrenal gland are quite rare, with only five well-documented cases reported in the literature. 1-4 Herein, we report the light microscopic and immunohistochemical features of two cases of this rare tumor. Patient 1 is a 34-year-old woman who presented with hypertension, hair loss, and amenorrhea of 1-year duration. Patient 2 is a 52-year-old woman who presented with flank pain and what appeared to be a renal mass on arteriogram with no history of hypertension, Cushing’s syndrome, or other endocrine abnormalities. At surgery, the tumor was noted to arise from the adrenal gland rather than the kidney and adrenalectomy was performed. In both cases, the surgically resected specimens consisted of a well-circumscribed, single adrenal mass surrounded by a rim of uninvolved adrenal cortical tissue. The tumors were composed of adrenal cortical cells intimately admixed with pheochromocytes. Immunohistochemical studies high- lighted these two cellular components. The pheochromocytes were strongly reactive with chromogranin and the sustentacular cells with S-100 protein, whereas the adrenal cortical cells reacted specifically with inhibin. Thus, we report two addi- tional cases of mixed corticomedullary tumor of the adrenal gland. Ann Diagn Pathol 5: 304-308, 2001. This is a US government work. There are no restrictions on its use. Index Words: Mixed tumor, corticomedullary tumor, adrenal gland T HE ADRENAL gland can be thought of as two separate organs, the adrenal cortex and the adrenal medulla, each with distinct structure, func- tion, and embryologic origin. Neoplasms arise from both components and typically present with differ- ent clinical symptoms. Tumors of the adrenal cor- tex include adrenal cortical neoplasms such as ad- renal cortical adenomas and carcinomas. Tumors of the medullary component typically present as pheochromocytomas. Tumors composed of both adrenal cortical and adrenal medullary tissue have rarely been reported. 1-4 To the best of our knowl- edge, the two cases described in this report repre- sent the sixth and seventh cases of true mixed corticomedullary tumor of the adrenal gland. There are a number of reports of synchronously occurring or coexisting adrenal cortical neoplasms and pheochromocytomas. 5-11 In the reported cases of true corticomedullary mixed tumors, including the two described herein, the adrenal cortical cells are intimately intermingled with the adrenal med- ullary component within a single tumor mass. Nei- ther the cortical nor the medullary component show cytologic features of malignancy. Materials and Methods The records of three patients with tumors diagnosed as “mixed corticomedullary adrenal tumors” were identi- fied in the files of the Endocrine Registry at the Armed Forces Institute of Pathology from 1970 to 2001. One case was excluded as it had been previously reported. 2 Materials within the Institute’s files were supplemented by a review of patient demographics (gender, age), symp- toms and physical findings at presentation (including duration), and past medical and surgical history. We obtained follow-up information by direct communica- tion with the pathologist and/or treating physicians. This clinical investigation was conducted in accordance and compliance with all statutes, directives, and guidelines of the Code of Federal Regulations, Title 45, Part 46, and the Department of Defense Directive 3216.2 relating to human subjects in research. Hematoxylin-eosin stained slides were examined in conjunction with immunohisto- From the Department of Endocrine and Otorhinolaryngic–Head & Neck Pathology, Armed Forces Institute of Pathology, Washington DC. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of Defense. Address reprint requests to Jacqueline A. Wieneke, MD, Department of Otorhinolaryngic and Endocrine Pathology, Armed Forces Institute of Pathology, Room G066-10, Building 54, 6825 16th St, NW, Washing- ton, DC 20306-6000. This is a US government work. There are no restrictions on its use. 1092-9134/01/0505-0009$0.00/0 doi:10.1053/adpa.2001.28297 304 Annals of Diagnostic Pathology, Vol 5, No 5 (October), 2001: pp 304-308